US2250500A - Abrading apparatus - Google Patents

Description

July 29, 1941. w. A. RosENBE-RGER ABRADING APPARATUS I5 Sheets-Sheet 1 Filed Sept. 21, 1937 QQQQ W//am Row/Mayer @0M yi/hw July 29, 1941. w. A. RosENBERGx-:R

ABRADING APPARATUS 5 sheets-sheet 2 Filed Sept. 2l, 1937 Chroma/g4.

July 29, 1941. w. A. RosENBl-:RGER

ABRADING APPARATUS Filed Sept. 21, 1957 5 Sheets-Sheet 4 July 29, 1941. w. A. osENBERGl-:R

ABRADING APPARATUS Filed Sept. 2l, r19557' 5 Sheets-Sheet 5 @j @i ao. 5,2535. fz

Patented `lolly 29, 1941 ABRADING APPARATUS William A. Rosenberger, Hagerstown, Md., as-

signor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application September 21, 1937, Serial No. 164,924

7 Claims.

The present invention relatesto abrading and cleaning apparatus and methods andmore par- Aticularly to methods of, and apparatus for, subjecting articles uniformly to abrading or cleaning blast streams at successive blasting stations, as shown in my application LSerial No. 34,990, led August 6, 1935.

In thek copending application of EricY O. Hamren, Serial No. 65,509, led February 24, 1936, now Patent No. 2,160,697, datedMay 30, 1939, is .disclosed an abrading apparatus in which Van article or casting is continuously rotated and simultaneouslysubjected to abrading and cleaning blast streams at a single blasting station to which it has been moved and before which it has been stopped by a suitable intermittent drive mechanism.

The present invention provides ,a machine having a v plurality of blasting stations before .whichthe articler or casting visstopped in suc-v cessive operations and is designed to overcome certain problems in abrading and cleaning ,to` be later brought forth.

It is aY primary object of the present invention ,toprovide a novel apparatus for abrading and clean-ingall portions of an article uniformlymand thoroughly by subjecting therarticle to abrading or cleaning action at successiveblasting stations.

A further object of my invention isy to provide, adjacent a path along which articles lor castings are guided, a novel arrangement of spaced blasting stations for directing blast streams at various angles upon `each of the ,articles as it pauses ,before .each blast station in succession.

It isa further object of my invention to provide a novel apparatus for Ymoving van article through an abradingzone made up ofa plurality of spaced blasting stations for directing blast streams at various angles upon the article and causingthe larticle to dwell fora substantial vmeasured length of time in the blast streamV at `each blasting station in succession whereby it is subjected to measured uniform abradingaction A further object of my invention- -is to provide anabrading or cleaning apparatus havinga p lurality oispaced vblasting stations for directing blast4 streams atvarious angles to al pathialong Vwhich,aplurality of articles may be moved, the articles being subjected to abrading action at each of the blasting stations in succession and wherein a plurality of articles may be operated upon simultaneously by the blasting stations.

A further object of my invention is to provide a novel conveyor mechanism for use in an' abrad- 10 abrading apparatus.

Aiurther object of my invention is to provide a novelinechanism for continuously rotating a ,Work vcarrierwhile it is in anabrading zone.

Another important object of my invention is `to provide ka .novel method of labrading 'and cleaning articles, especially long castingswherein each articleismoved through an `abrading Zone made up of a plurality of spaced blastingsta'tions and caused to dwell for a substantial length of time before eachblasting station in succession whereby v'it is subjected to a plurality of diierent and, independent abrading `actions directed at variousangles.

Another'import'ant Vobject of my invention'v is .2 5 to providea: novel method ofabrading and cleaning rotating varticles lwhvereinthe' articles are subjected to blast streams successively lfrom spaced offset blasting stations to insure thorough cleaning action.

.30 Otherobjects of the invention will be apparent from the` following description and the appended claims taken in connection with the accompanyingdrawings wherein:

- Figure lis a photographic view in elevation of a complete apparatus embodying the invention showing the general operation of the apparatus inactual use and especially the vertical spacing `Voi the several blastingstations.

Figure 2 is aright-hand end View partly` in 40 sectionV illustrating the arrangement of some of the blasting stations and the entryv by which the work enters the abrading zone.

Figure 3 is a diagrammatic view illustrating a ,preferred -arrangement of the `several blast wheels; withrespect ,to the casting or otherwork to be. blasted.

. .Figure 4 Vis adiagrammatic Atopplan view of jtheapparatus of theinvention showing ,thel closed patnkalong ,which the `work isguided and the .spaced `relation of thewseveral blasting stations.

ing apparatus for moving a continuously rotating zone.

Figure 6 is an enlarged sectional view showing the details of the work carrier guides and chain drive at the abrading zone.

Figure 7 is a diagrammatic end View partly in section of the abrasive propelling wheel used at each blasting station in the apparatus.

Figure 8 is a side View on an enlarged scale illustrating the conveyor and chain drive mechanisms.

Figure 9 is a plan view of the drive mechanism of Figure 8.

Figure 10 is an end View partly in section 'cf one type of reciprocating mechanism for eiecting intermittent movement of the conveyor.

Figure 11 is a detail of the pawl mechanism of Figure 10 for engaging the work carriers.

Figure 12 is a sectional view showing the middle chain supporting sprocket and its support.

Figure 13 is a sectional View of one of the elongated chain guide members also illustrating its manner of support.

Figure 14 is a plan View of another type of reciprocating mechanism for eiecting intermittent movement of the conveyor.

Figure 15 is a side elevation of the mechanism of Figure 14 illustrating especially the conveyor chain drive.

Figure 16 is a view taken along lines Iii-I6 in Figure 15 illustrating further the conveyor chain drive.

Figure 17 is an end View, partly in section, of the reciprocating mechanism of Figure 14.

Figure 18 is a plan view, partly in section, of a pull rod embodying a safety device.

Figure 19 is a view taken along line Ill-I9 in l'.

Figure 18 further illustrating the safety device.

Figure 20 is a section taken along line 20-26 in Figure 1S.

Figure 21 is a section taken along line 2I-2I in Figure 18.

Figure 22 is an end view, partly in section illustrating the yieldable guide section mounting.

Figure 23 is a section taken along line 23-23 of Figure 5 showing the guide section pivot.

Figure 24 is a section taken along line 24-24 Il of Figure 5 illustrating further the guide section support.

Figures 25a, b and c illustrate a novel blasting arrangement and method in which the blast stream is offset with respect to the rotating Work.

Like reference characters are used to designate like parts.

With especial reference to Figures 1, 2 and 4 the whole apparatus is supported upon a base II and extending longitudinally of the base is a E' chamber I2 containing a plurality of blasting stations and dening a region which will be hereinafter called an abrading zone. Above the chamber is supported an endless guide rail I3 from which depends a conveyor I4 bearing a plurality of work carriers I5.

For intermittently moving conveyor I4 along the guide rail a one way drive mechanism generally indicated at I6, and driven from an intermittent drive generally indicated at I'I, is slidably mounted on the guide rail and adapted to position each work carrier in succession before the successive blasting stations. A continuous chain drive generally indicated at I3 in Figure 4 engages and rotates continuously the work carriers while they are in the abrading zone.

Abradzng zone Chamber I2 enclosing the abrading zone has a vertical side wall I9 upon which are mounted four abrasive propelling wheel housings 2 I, 22, 23 and 24 which open into the interior of the chamber. Each housing includes therein an abrasive propelling wheel 25 of the type shown in Figure '7, in which a rotor 26 is provided with a plurality of substantially radial blades 21 which terminate short of the central axis about which the wheel rotates to define a central abrasive admitting space.

Rotor 26 also supports an impeller blade assembly 28 surrounded by a cylindical hollow control member 29, provided with a discharge slot 3 I. Control member 29 is adjustably mounted to rotate about its axis with respect to the rotor and in this way eiective directional control of the discharged abrasive is obtained. This abrasive propelling wheel per se forms no part of the present invention and is disclosed in more detail in the copending application of myself and Walter L. Keefer Serial No. 726,188, iiled May 17, 1934.

As clearly shown in Figures 1 to 3 the four abrasive propelling housings define four individual blasting stations. Housing 2I is secured in any suitable manner as by bolts to a flange 20 which surrounds the blasting station opening in wall I9 and is therefore removable at will. Interiorly of housing 2I the rotor 26 is mounted upon an extension of shaft 32 which is driven through a suitable enclosed power transmitting unit 33 by an electric motor 34 also secured to wall I9. Housing 2I is provided with a door 35 for inspection of rotor 26, for replacement of blades 21 and housing liners and for like purposes, Without entering chamber I2.

Inasmuch as each of the blasting stations are of substantially the same construction, it will be merely pointed out here that the rotors in each of the housings 22, 23 and 24 are provided with individual motor drives similar to that described for the rotor in housing 2i Besides being spaced horizontally as shown in Figure 4, the blasting stations are stepped vertically as shown in Figures l and 2. Furthermore, the abrasive propelling wheels in housings 2I and 22 are preferably over shot Wheels While those in housings 23 and 24 are preferably under shot wheels. Either type of wheel, however, may be used at any station as desired for the particular type of work being handled.

Thus the stepped vertical spacing of the blasting stations, the above described angular control at 29 for the abrasive discharge streams and the optional use of undershot or overshot wheels all combine to provide an abrading zone which will thoroughly subject to abrading action articles of greatly varying shapes and sizes.

In Figure 3 is diagrammatically shown the operation of the spaced blasting stations 2i', 22', 23 and 24 in effectively subjecting every part of an elongated piece of work W to abrading action. Here the two lower wheels are undershot while the upper two are overshot to gain the desired abrading action.

As shown in Figure 4, chamber I2 is provided with an entry chamber 36 and an exit chamber 3l. Each of these chambers is provided with a plurality of iiexible self-closing doors 38 secured at opposite sides of a passage 39 and are adapted to be pushed open by the moving work as shown in Figure 4. End wall 4I of chamber 36 is provided with an elongated opening 42 which terminates in a vertical slot 43, the purpose of which will be later described.

llZor-k Qmoving -mecham'sm Although any suitable .guidewaymayibeused for .supporting .conveyor :I Il, I prefer touse :a guide :rail i3.shapedsubstantiallyas an I-.beam rigidly secured: to basa I I byfsupportsorsuspended fromoverhead byv brackets, which-'arelomitted for the sake of clarity in disclosing-theinvention. Guide rail I 3 iormsa closedhorizontallpath having -a-straight portion disposed nabove the abr-adingzonel as shown in Figure 4.

Guiderail I3 has acentral--web AIM 'and two parallel flanges `ll5--andA `116extending outwardly from opposite sides -of the web and servingas vguide supports `for two.- hangerwheels L1 Sand 48 respectively. -Wheel-Alis journaledat the-upper end of arm 49 which extends downwardly and ninwardly .and terminates in .adownwardlyxtending :portion 5|. extending -substanti'ally.paral.. lel to -web 44 .(Figure. v6) .i

.Wheel -41 isjournaledl at-.theluppenend ofaarm 52. similar to arm 49.andf.terminating,in adownwardly extending .portion 53 substantially par.- allel to web 44. A generally;Ceshapedhangerjl is provided with a. rigid upstandng flatlplate 55 which ispreferably integral with fhanger .54. Plate 55 is. ofvsuch thickness that itts snugly between downwardly extendinglarmportions 5| and 53 and Iall three members 5|,f53-and 455 are secured together rigidly by .bolts-or other suitable means. Plate 55 ispreferably centeredlvertically with respect to web 54,

At the lower end-of hanger 5l|iis avertically disposed cylindrical'boss 56 also centered with web 44 and in rwhich is supported a hanger bearing shaftr51. A ball bearing has its inner race58 secured to shaft 51 near the top of boss 56 and its outer race 594 fitted in gan internal annular shoulder 6| cut inboss 56. A second ball bearing has its inner-race |52V secured to .shaft 51 -near the bottom of boss 56 and has its outerrace 63 secured in an internal annular shoulder 64 cut in the lower end of boss 56. The inner .races 58 and 62 are separated by a cylindrical spacer member 65 surroundingl shaft 51- and-shaft 51 iS provided with an enlarged portion 66 rfor engaging the lower end of b'earingring 62.

The upper end of shaft 51- is provided with a stubv61 of reduced cross-section .and loosely mounted on this stub is a substantially cup shaped bearing collar 68` havingl a` hub. portionA 69 engaging the top bearing andan externalfflange 1I tting rover. a short cylindrical boss extension 12 of` reduced cross-section. Stub 61 is threaded at'the upper end and mounts a nut 13 which bears on the top of collar 68 and clampsthe latter rigidly against innerbearing'race 58. `Running clearancev is provided between exterior flange 1| of Vcollar 68 and extension-12 ofz boss 56.

Asshown at in Figure 6, a sprocket `14 is suitably and non-rotatively secured to shaft 51 below boss 56. A locknut'16, cooperating with a threaded portion '11 on shaft 51, forces sprocket 'lll 'upwardly against the enlarged shaft portion 66 and thereby secures the sprocket against movement Aaxially of shaft 51. 'Sprocket '14 is provided with a plurality of teeth 18 the purpose of which will later be described.

Shaft51 ends Ia shortdistance below sprocket 11i. A rod 'H3' is :suitablyand' non-rotatably securedtothelower-end of shaft51 vby means of a removable. coupling l 19. Rod 518' 1 is provided=at itslower end with lalhook -83 ('seeiFigurellyor some f similar .formation lto which worklto be ab'raded or cleaneds attached.

Belowcol-lar 19, rod 18' extends through a-s1ot -Yinthetop wall88 of chamber .I-2. This slot and its seal belowdescribed extendsthroughout the chamber =I2,' including chambers A{i6-and 31. Suitable .means are provided for sealing A oi the slotl to4` prevent abrasive rand rvdust from escaping therethrough. 'Verticali-y disposed walls |30Y and define a chamber lpassage vextending downwardlyfroml slot -80 .-Wa1fls-84- and 35V are Iprovidedv .with outwardly extending foot port-ions 86 #and l-r'espectively `forsecuring the 'same -to under side ofthetcp -wall 88 lofA chamber -|2 Edgeplates 89^and 9| definey -the edgefo slot -80 above wall 88. At one side of the slot, members 36,88 and 69are secured together-asbyboltsor rivets Jandai; the-other side of --the slotfrrxeinbers 81,-.88and19I are similarly-secured. v

.AA thin vmetal bracket 52-fis secured -.to -wall L84 and fhas an #upper lipA portionv 93 secured `to the under iside? of plate-89 and extending Iat right angles--towardrod -1-8.- Lip 93 terminates --adjacent rode18' and clamped between lip `93- anda longitudinally extending metal strip 94-is^a-sheet of --flexibleematerial 95 such as felt, rubber, lea-the er, etc. normally tending to extendfhorizontally. The: lower endf96 o-'bracket 52 is-bent-downwardly and inwardly and terminates adjacent'rod 18"; A strip of exible material illnormally tending to extend-in alignment withbracket end -96'is' securedibetween' the bracket --endl 96' and -a backing strip 598' by rivets v95 or .some other suitable means. Y 1 f A duplicate bracket 92 is secured to plate A9| and-wall05 at theother Yside'of ythe-slot. Flex-4 ible 'members'S and 91 are of such-length that they-would `completelyclose-the slot were it not for the presence ofrod 18. However-when-ro`d 1-8'-'is passingalongI-the-slot these flexible strips are bent downwardly-to-intimately engage opposite sides'of rod-18 andcooperate to provide an elective sealingmeans.

Hanger-54--isprovided on.- the oppositey sidefrom boss 56 with-a p'air of horizontally `extending apertured lugs |0I and |02. -PinI03-extends between lugs |0| and |02 respectively and' is -securedtheretoby cott-er-pins |04-and |05 or-the like fasteningimeans. Guide roller |-061is journaled onpin'l03 betweenthe lugsandengages guides -I |209Lbol-ted at -1 ||0vto-frame member |01. Flange |08oi frame'memb-er `-|01 is preferably provided .with slots y||-| to allow-'horizontal adjustments of the. guide i I 09.

Directly opposite` the position where the work rotating sprockets '14 start to engage thechain I8, a short guidesection `Iillais adjustably and yieldably-supported upon the'framermember |01. neiendof iguide sectionf|09ais provided with a circular aperturel 236 tting about anv enlarged cylindrical portion 231 on. a guide sectionfsupport bolt 238. The upperfend offboltl238 cooperates with a sloty I II in'stheframe-member |01 to allow horizontal adjustment *oi the Vguide section. Guide "section l'a'iis'rotatable about post 231 asa pvot. V

.'Nearfits other end' guide section IilotV is suppartes .by-:a secondA boit :239 similar to` but 123s, butherelthe guide sectionv aperture-"is an elongatedarcuate slot 24| allowing limitedrotation of-'Tguidelisection `|09a"about its pivot post 231.

At'rthe" rear of vguide section '|'09a, and intermediate: the support bolts, is provided av-substantially 'semi-circular groove 234. -A rod 123|, threaded substantiallyalongitsentire lengthgis provided with a' dat-head which -fextendsbetween the walls of the groove and isy pivotally mounted therein by means of pin 232,. The other end of rod 23| is supported in a bushing 226 upon the upturned leg of a substantially L-shaped support 225 rigidly secured to frame |01.

Rod 23| has mounted thereon a coil spring 236 which is compressed between anges on the bushing 226 and collar 221. Nuts 228 and 229 threaded on rod 23| abut bushing 226 and collar 221 respectively and maintain spring 23u under; compression. Adjustment of nut 229 regulates the compression of spring 230. Adjustment of nut 228 changes the eiective length of rod 23| and hence tends to rotate guide section IUSd-about its pivot 231. v

It will be noted that springi239 normally tends to maintain the guide position of guide section |9911 in alignment with guide |09. However, in case a tooth of sprocket 14 should, upon engaging chain I8, contact a chain roller 22|] rather than the space between adjacent rollers, the guide section |69a will yield under the pressure and pivot about post 231 against the action of spring 239. This permits the sprocket tooth to slide past the roller into the next space between the rollers without causing jamming or injury to the apparatus. After the sprocket has passed, spring 23|) returns the guide section |09a to alignment with guide |69.

Asshown in Figure 6, guide angles 242 and 243, forming a guide channel throughout the length of chamber |2, are provided on opposite sides of the rods 18' just above the sealed slot in wall 85. These guides prevent excessive swaying of heavy articles mounted on rods 18'. With reference `to Figure 5, it will be noted that guide 242 is provided with an offset portion 235 opposite sprocket |92 to permit sidewise motion of the rod 18 when a sprocket tooth initially engages a chain roller as explained above.

The above described work carrier is connected to conveyor chain I4 in the following manner. At each work carrier an apertured link H2 embraces the work carrier and as shown in Figure 6 fits snugly in grooves H3 and ||4 on opposite sides thereof. Since each link H2 has closed endswhere it is pivoted to the adjoining link, conveyor chain I4 thus interconnects all of the work carriers for simultaneous movement. A further interconnection between adjacent work carriers is shown in Figures 1 and 5. Each hanger 54 is provided with oppositely extending lugs H5 and H6 upon which are pivoted links |1. One end of each link H1 is slotted as at H8 to compensate for the outward swing of the lugs upon a curve in the guideway.

Conveyor chain I4 and the attached work carriers are moved intermittently along giude |3 by any suitable intermittent drive such as the well known pitman drive at |1 actuating a one way clutch mechanism I6. It will be apparent that other equivalent intermittent drive means such as a limit-switch and time-relay controlled electric motor can be used for the same purpose as the strictly mechanical drive above described. In fact, the use of any mechanical, electrical or hydraulic intermittent drive is well within the scope of the invention. With reference to Figures 4 and 8 to 11 a motor ||9 is adjustably mounted in suitable slide guides upon a rigid frame member |2|. Upon the motor shaft |22 is mounted a pulley |23 connected by a belt |24 toa pulley |25 on the shaft |26 of a speed reduction mechanism contained in housing |21.

Driven shaft |28 extending from housing |21 carries a pinion |29 which is meshed with a gear |3| xed on a shaft |36 which is journaled and suspended in suitable brackets |32 and |33 afxed to the frame. Gear |3| is provided with an eccentric pinY |34 engaging a slot |35 in a link |36 pivoted at one end at |31 to the frame and having a reduced extension at the other end pivotally mounted between the jaws of bifurcated member V| 38.

1 A second link consists of two aligned arms |39 ano'. |4| having adjacent ends threadedly engaging a turnbuckle |42. Upon the other end of arm |39 birurcated member' |36 is threadedly secured and at the other end of arm |4| is threaded a. block |43. All of the threaded connections at either end of arms |39 and |4| are locked by suitable nuts |44, |45, |46 and |41 as shown in Figure 9.

Block |43 is centrally bored at |48 to receive an upstanding pivot |49 secured to plate |59 at the top of clutch mechanism I6. A pair of duplicate arms |5| extend downwardly from plate |50 on opposite sides of guide I3 as shown in Figure 10. Each arm |5| has'a horizontal top flange |52 rigidly secured tothe bottom of plate |50, a downwardly extending vertical portion |53, a downwardly and outwardly extending portion |54, a downwardly and inwardly extending portion |55 and a short downwardly extending vertical portion at |56.

Secured rigidly to the top ange of rail I3 is a guide member |51 having a horizontal supporting guide surface |53 and two angularly disposed guide surfaces |59 and |6| on opposite sides thereof. A guide roller |62 is rotatably journaled in arm portions |53 and is supported upon surface |58. Arm portions |5| are provided with rollers |63 and |64 adapted to engage guide surfaces |59 and |6| respectively. It will therefore be seen that the frame made up of plate |59 and arms |5| is supported for movement along guide |51 by roller |62 and prevented from turning laterally thereof by guide rollers |63 and |64.

Each arm portion |56 (Fig. 11) has a pair of inwardly extending lugs |65 and |66 between which is pivoted a pawl |61. Secured to each portion |56 at one side of the pawl is a stop |68 preventing pivotal movement of the pawl in that direction and a spring |69 interconnects the pawl and stop |68 to tend to maintain the pawl normally pressed against the stop.

Secured upon the upper end of shaft |39 (Fig. 8) is a sprocket |1| which is connected by chain |12 todrive a similar sprocket |13 fixed to the upper end of shaft |14. Shaft |14 is rotatably suspended in suitable bearing brackets |15 and |16 secured to the frame and is provided with a flexible coupling portion |11 intermediate its ends. To the lower end of shaft |14 is xed a double sprocket |18 adapted to drive the chain I8. Shaft |14 is disposed at one end of the abrading zone and midway of the abrading zone is supported rotatably a double idler sprocket |19, mounted for rotation about stub shaft |89 which has its upper end secured as by welding to a plate |6| as shown in Figure 12. Plate |8| is secured to the underside of a rigid frame portion |82 by bolts |83. Slots |84 are provided in plate |9| to enable the plate to be adjusted laterally toward and from the work carriers. Bushing |85 surrounds the lower end of shaft |89 and is rotatably mounted thereupon by suitable ball bearing members |86 and |81 spaced by a cylindrical spacing element |88.4 A nut |89 upon the 'threaded lower end o'f shaft |30 'maintains the bea'ing'assembly in position.

ASprocket 'I1-9 lis fsecured to A'bushing =I`185 by vany suitableineans such as `s'crews I9I. 1 Thus, idle `'sprocket |19 serves as av support "and guide for chain I8 'to prevent 'excessive sagging and thus assures vproperniesh of chain |8 'and sprocket teeth '18.

Shaft ll1'4 -('F-ig. 46) below `the lbearing assembly |16, is provided with an enlarged `portion |96. Extending beyond "enlarged shaft portion I 96 -is a reduced shaft portion 292 provided with a keyway 1203. v'Sprocket |18 is provided 'with a keyway 294 at `its inner 'bore 'and theshaft and sprocket are Ynon-'rotatably'secured together by a suitable key 2&5 iitting in those keyw'ays Sprocket |18 4is clamped longitudinally upon shaft portion 292 in engagement with enlarged portion |95 atits upper end. At the lower end lof sprocket |18 a washer 2'96 is forced upwardly 'byya lnut '201 mounted 'on theeducedfand "threaded shaft end 258 :to secrefth'e sprocket againstldngitudinalinovenferit. Af'shaft "I 92 {(see Figure :)M upon 'whieh 'is mounted a sprocket 1524, is ya duplicate offthe `-shaftassembly at |14 lju'st deseribed'ex'cpt for the drive'sproketl13 and 4is used to `su1zport and guide chain I8 at the otherend of the ab'radin''gv zone. l

Guide |09 prevents the work arriere from being 'forced A"awayffrfom'chain 8. Suitable guide Iineinher's 299 -and 2| are provided to assist sprocket |19 in preventing chain lfrmbeing pushed Vlto'o 'far Vin 'the ppo's'ite direction.

'Guide 2091'as `show'n in Figure 13 isfsec'ured as 'by -'c'ap screws 2`I'Il to any angleniember 2'I2 which isboite atz l 3 'tothe undersioe or framemejmber |872. Angle member A'2|'2 's provided with slots It'will be Ynoted that the chain links 242|, 222, I'

-22f3, 224'are `v-not engaged by lany of the vsprocket members.

'Since guide vnmmbers 209 'andv 21| "are duplicates th'e latter 'will not vbe described in 'detail'.

Operation Castings or any 'articles' 'to 'be 'abraded or Clean'edare mounted upon the work carrier hooks 83 at a station located at any portion of "the laitipara'tus outside the ab'radi'ng zone 'and along guideWayfIS. Preferably Athis station is Vlocated at 'the right 'in 'Figure k1 and `Fig'ure'l, just before the ventrance doorway 42 of 'chamber 35.

The conveyor v|4`andfa'll Aof Ythe supported work carriers jare intermittently m'oved along guideway I3 by operation of the 'crank k|34 which causes reciprocation of the one way clutch mechanism Ialong guide |51. In its travel to the left inY Figure 4 clutch mechanismk I6 advances the-conveyor a full step but lupon return movement Vof clutch I6 the `pawls are swung aside as .shownin dotted lines in Figure 1l and do not move the conveyor.

As the `conveyor movesjalong lthe guideway I3 the -work'enters doorway 42; see Figures v1 and 4,

proceedsthrough the self closing doors y38 to thegabrading'zone i2. I:

The intermittent movement is so arranged that upon 'entrylinto the abradi'ng `Zone 4rthe first -dwell` period of theworkvoccurs adjacent' andrl 'the blast vstream from "the rstblas'ting station "2L "However, the moment the work 'carrier enters vthe abrading zone, sprocket V14 is lcaused. to engagea section of continuouslymoving chain 18 'arranged parallel to the :guide |3 Vat that zene. Thus the Work is continuously rotated during the time itis passing vthrough the 'abrading chamber.

Afterits dwell period at the 'first station, which lperiodvis timed to -permit at `least 'one complete revolution or any desired whole number of `com- Ipletefrevolutions of the work to secure uniform rabrading "action, the work i'smoved to position `before each succeeding blasting zone in order "for asimilar dwell period. Theiblast Astreams at 'the various blasting stations are 'preferably vdirected at Various angles to secure more uniform 'and complete abrading action.

It will -be seenthat in thesabove described embodiment of my invention 'eachr'p'iece' o'f'work is subjected in succession 'tofourindividual blasting operations before it moves into the exit chamber 131. Each separate `operation accomplishes a definite abrading action land Yall four `combine to thoroughly and-uniformly subject `the whole piece of work to abrading action.

Modified Meinl-booting mechanism Figures 15 to 1'1 illustrate a modified form of reciprocating clutch mechanism which has 'been found very efficient in operation. In this embodiment, a substantially horizontal topplate 244 has rigidly secured thereto'depending side frames 245 and 246 which eXtenda substantial distance below rail I3 Yon either side thereof. A vertical post 241 vis secured as by welding to 'the topplate.

Secured tothe top of v.rail I3 is a guide support 248.1upon which thel clutch mechanism -is reciprocated. At each Ycorner of -platef244 is secured a bracket 249 whicheXtends beyondthe edge of theplate vand rotatably carries a 'guide wheel 25|. VThese four wheels 25| serve to support the vclutch mechanism for movement-alongguide 248.

Each bracket 249 also carries a rotatable guide wheel 252 whichengages the Vlower inclinedgu-ide surfaces of guide 248toprevent the clutch mech- `anism from'being rotated aboutV the rail I3.

`vVertically disposed rods l253 and 254 'are A-rotatably supported in the side frames 245 and 246 respectively.- Secured non-rotatably, as by pins 255, to the lower ends of rods 253 and 254 are conveyor chain engagingarms 256 and 251respectively. The free-ends of arms 256 and 251 are .preferably rounded as shown in Figure 16 for positively contactingl cylindrical cha-in portions but it will be `obvious that these arms may assume any desiredY shapewithout departing from thespirit of Ythe invention. It will be Yobvious that rotation of - rods 253 and 254 in opposite directions will move arms256 and l251 to and fromchain engaging positions.- v

-As shown in Figure 15, -rod 254 extends upwardly through an aperture infplate 244 and is provided with a ycircumferential bearing ilange 258 engaging the top surface of `plate 244. A fiat link 259 is provided with a hollow=boss 25| which fits over -the top of rod 254 and is non-rotatively .secured thereto as by apin 262. Link259 carries rotatably-at its free-Vend a second link 263 which in turnis rotatably mounted atthe end of the [reciprocating pull rod generally designated 'at 25E). A'similarpair lof links^264 and 255 connect rod. 25e .tothe end'pf 'the puurod 12st.l

shown in Figures 14 and 18 the end of the pull rod to which the clutch mechanism is attached comprises a flat plate 266 having an elongated slot 261 longitudinally disposed therein. Slot 261 is adapted to receive slidably the post 241 for a purpose to be later described.

Rigidly secured to the other end of plate 266 is a tubular sleeve 268 and slidably mounted within sleeve 268 is a rod 269. Rod 269 has at its outer end an eared portion 210 adapted to engage a suitable eccentric mechanism such as the link |36 of Figure 9. Intermediate its ends rod 269 is provided with a turnbuckle 21| for adjusting the point at Which the Work supports will dwell in the blast chamber. The turnbuckle is held in adjusted position as by locknuts 212 and 213.

A collar 214 is rigidly and non-rotatively secured to rod 269 near the end of sleeve 268 and is provided with a beveled surface 215 for a purpose later to be described.

Supported upon the end of sleeve 258 is a safety release which is operative to prevent damage to the work moving apparatus or the article being abraded by permitting separation of the sleeve 263 and the rod 269 when the pull on the pull rod is in excess of a predetermined amount. This safety release is supported by a pair of spaced plates 21| rigidly secured as by Welding to diametrically opposite sides of sleeve 268. Below and above the sleeve 268, plates 21|' serve as pivots for axially extending links 216 and 211. Links 216 and 211 are provided, intermediate their ends, with inwardly extending ta pered ears 218 and 219 respectively for a purpose later to be described.

A cross-bar 28| is rigidly secured to the outer end of link 211. Pivotally mounted at opposite ends of cross bar 28| and extending past opposite sides of rod 269 are a pair of threaded rods 282 and 283. These rods 282 and 283 extend through apertures in angle members 284 and 285 respectively secured to opposite sides of lower link 216. Y

Angle members 284 and 285 are limited in movement in one direction along the rods by suitable adjustable stops such asthe nuts 2864 and 261 threaded upon rods 282 and 283 respectively above the angle members. Angle members 284 and 285 are yieldably urged against these stops by coil springs 288 and 289 respectively and the tension of these springs is ladjustably controlled by suitable means such as the locknut andwasher assemblies indicated at 28| and 292 respectively in Figurelg.

In operation, pull rod 260 acts substantially as a solid rod with collar 214 contacting the end of sleeve 268 and the link ears 218 and v219 upon opposite drive strokes. Referring to Figure 14 it Will be noted that, due to elongated slot 281, initial movement of the pull rod to the left operates through links 284, 265 and 263, 259 to rotate rods 253 and 254 and hence arms 256 and 251 in opposite directions. Thismovement positively insures release of chain |4 by the clutch mechanism.

As soon as arms 256 and 251 release the chain, the end of slot 261 contacts post241 and the whole lclutch mechanism is positively moved along guide 248 for the idle stroke. Movement of pull rod 260 to the right obviously causes initial movement of arms 256 and 251 A to the chain engaging position shown in Figure 16 and subsequent movement of the clutch Arlrlechanism andthe chain to the right.

In the event that a piece of work becomes jammed, or if for any other reason the force resisting feeding movement of the clutch mechanism becomes excessive, collar 214, due to its beveled face 215 and the tapered ears 218 and 219, will force links 216 and 211 apart against the action of springs 288 and 289 and thus allow separation of sleeve 268 and rod 269 without damaging the apparatus. The several adjustments on rods 282 and 283 allow this separation to take place at a desired predetermined stress.

It will be obvious that the pull rod shown in Figure 9 may be used with the clutch mechanism of Figures 14 to 17 and the pull rod of Figures 18 to 21 may be used in place of that of Figure 9 since these parts are unitary and interchangeable.

Method of offset blasting In Figures 25a., 25h and 25o I have illustrated the advantages of my novel method of abrading rotating articles in securing thorough abrasive action. Figure 25a. represents one system of directing a blast stream centrally of the axis of rotation of the work. Here the Work is just about to complete a 360 degree rotation in the blast stream and, as indicated by the zig zag line, portions A to C and B to D on the inside of the work have not been subjected to abrasive action due to the cut-off eifected by the edges at A and B.

In my arrangement for cleaning substantially circular articles of this type such as cylinder blocks and other automotive castings I preferably position the blast streams from the first two blasting stations slightly offset to the left with respect to the centers of rotation of the work before those stations. Figure 25h shows the work just before it has completed a full revolution at the station and it will be noted that all portions except the areas B to E have been cleaned.

Figure 25e illustrates the same piece of work near the end of a complete revolution before each of the third and fourth blasting stations. Here the blast stream is offset slightly to the right with respect to the center of rotation of the work and all parts of the Work are subjected to abrasive action except the area A to F. However, area A to F was cleaned at the first two stations as shown in Figure 25h and it will thus be seen that the combined action of all four blasting stations thoroughly cleans the entire work surface inside and out. e

In carrying out the above described method the blast streams must be adjusted to give such a vertical spread of abrasive as to insure cleaning of the work from top to bottom and therefore it will be seen that the method is best effective upon short pieces of work rather than the longer pieces as illustrated in Figure 3.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In an abrading apparatus for blasting articles of relatively large size, a support, means providing an abrading zone, means for intermittently advancing a plurality of articles in sequence through said zone, comprising an endless substantially horizontal guideway on said support above said abrading zone and a plurality of individual article carriers movably supported from said guideway and adapted to be moved therealong; means to suspend said articles from said carriers; clutch means slidably mounted on said guideway, and drive means for reciprocating said clutch means along said guideway, said clutch means being operable to drivingly engage and propel said carriers in one direction of motion, whereby said articles are intermittently advanced through said abrading zone.

2. The abrading apparatus defined in claim 1, said clutch means comprising pivoted pawl mechanism engageable with said article carriers.

3. In the art of cleaning articles such as articles having relatively deep cavities therein by abrading, the steps which include moving an article along a predetermined path of travel and halting it in position before a blasting station, establishing a blasting stream at said blasting station with an impingement pattern elongated in a vertical plane, rotating said article through at least one complete revolution about an axis oiTset in the direction of work travel of said article with respect to the approximate vertical axis of the blast stream from said station, moving said article to a second blasting station and halting it, establishing a second blasting stream at said second blasting station with an impingement pattern elongated in a vertical plane, and rotating said article at least one complete revolution about an axis offset with respect to the approximate longitudinal axis of the blast stream from said second station, said last named offset being in a direction opposite to said first named offset, said blast streams having dilerent directions relative to the direction of rotation of said article.

4. In an abrading apparatus, a support; means providing an abrading zone; means for intermittently moving articles through said zone comprising a guide; a plurality of article carriers movably mounted on said guide; a member mounted to reciprocate along said guide drivingly engaging an article carrier in one direction of motion only; means pivoted at one end to said member and at its other end to a slotted lever pivotally mounted on a fixed pivot; an eccentric member engaging said slotted lever; drive means for said eccentric member; means for varying the speed of said drive means; and means for adjusting the effective length of said link, for adjustably varying the point where said carriers will stop in said abrading Zone.

5. In an abrading apparatus, a support; means providing an abrading Zone adjacent said support; means for intermittently moving articles through said zone comprising a guide structure upon which a plurality of article carriers are movably mounted; a member mounted to reciprocate along said guide structure and operable to drivingly engage an article carrier in one direction of motion only; a link pivoted at one end to said member and at its other end to a lever, said lever being journaled on a fixed pivot; and crank means for reciprocating said lever; means for rotating said crank means, said crank means and said lever being so related that said member is reciprocated at a greater speed in said one direction of motion than in the opposite direction of motion,Y whereby the time of dwell of said articles is -greater than the time required to advance the articles into blasting position.

6. In an abrading apparatus, a blasting zone; a conveyor mechanism including a plurality of carriers for conveying a plurality of work units in a substantially horizontal i'lxed path of travel inr sequence through said blasting zone; said carriers being spaced apart on said conveying means a predetermined distance from each other; a plurality of blast means disposed in said blasting zone and spaced apart along said path of travel of said work units and at the same side of said path of travel for providing a plurality of spaced lblast stations in said blasting zone; means for intermittently advancing said carriers step by step a distance substantially equal to the spacing of said carriers from each other, and for stopping one of said carriers in each of said blast stations, whereby said carriers are caused to dwell and said Work units are subjected to the action of said blast means for a predetermined length of time; means for rotating said carriers at least while they are disposed at said blast stations, each of said blast means embodying means for projecting abrasive at high Velocity across the path of travel of said work units, one of said blast means being disposed to project its blast stream oiset a slight distance rearwardly of the axis of rotation of the work unit being treated when halted with respect to the direction of advance of said work units, and another of said blast means being disposed to project its blast stream o'set a slight distance forwardly of the axis of rotation of the work unit being treated when halted with respect to the direction of advance of said work units.

7. In the art of cleaning articles by abrading, the steps which include suspending an irregular shaped article in' depending relationship, conveying said article to an abrading station, halting the article at said abrading station, rotating the article about a substantially vertical axis through at least one complete revolution While subjecting it to the abrading action of a stream of abrasive particles projected at high velocity in a direction substantially normal to a plane passing through said vertical axis of rotation'of said article, and in a direction offset relative to said vertical axis of rotation of said article, then advancing said article to a second abrading station, halting the article in said second abrading station, and rotating the article through at least one complete revolution while subjecting the article to the action of a second stream of abrasive projected at high velocity in a direction substantially normal to a plane passing through said vertical axis of rotation of said article and in a direction oiset relative to said vertical axis of rotation of said article, said last-named offset being in a direction opposite to said first-named offset.

WM. A. ROSENBERGER.

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