US2131769A

US2131769A - Apparatus for treating metal articles

Info

Publication number: US2131769A
Application number: US97100A
Authority: US
Inventors: David C Turnbull
Original assignee: American Foundry Equipment Co
Current assignee: American Foundry Equipment Co
Priority date: 1936-08-21
Filing date: 1936-08-21
Publication date: 1938-10-04
Anticipated expiration: 1955-10-04

Description

' Oct. 4, 1938. D. c. TURNBULL 1 2,131,769

' APPARATUS FOR TREATING METAL ARTICLES Filed Aug. 21, 19 36 6 Sheets-Sheet l in? INVENTOR DA W0 6. TU/P/VBULL.

ATTORNEY Oct. 4,

1938. D. c. 'TURNBU LL APPARATU FOR TREATING METAL ARTICLES Fild Aug. 21, 1

6 Sheets-Sheet 2 XXRNKkXXWa 0/: v10 6. Tum/BULL.

A ffo Rnw 6 sheeis -sheet s INVENTOR DAV/0 C. T/R/VBULL.

WNW

ATTORNEY D. C. TURNBULL APPARATUS FOR TREATING METAL ARTICLES Filed Aug. 21, 1936 Oct. 4, 1938.

- Oct. 4, 1938:] Q D. c. TURNBULL I 2,131,769

APPARATUS FOR TREATING METAL ARTICLES Filed Aug. 21, 1936 GSheets-Sheet 4 g, 0| I! fi I u; a Q i 0 & INVENTOR DAVID C. 7Z/R/VBl/LL. R

ATTOR;NEY

Oct. 4, 1938. C. TURNBULL 2,131,769

APPARATUS FOR TREATING METAL ARTICLES Filed Aug. 21, 1936 6 Sheets-She'eb 5 nmmm ,.IIIIIIIIIIIIIIIIIIIII -m mum:- I.

"I" II I;/ I A I'Inu [07 &

Q ,J-q/

INVENTOR DAVID C. Tun/v50.

ATTORNEY O 4, 1938. D. c. TURNBULL 2,131,769

APPARATUS FOR TREATING METAL ARTICLES Filed Aug. 21, 1936 6 Sheets-Sheet 6 INVENTOR DA vm C. 717/P/v81/LL.

Patented Oct. 4, 1938 APPARATUS FOR TREATING METAL ARTICLES David C. Turnbull, Mishawaka, IndL, assignor to American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application August 21, 1936, Serial No. 97,100

12 Claims.

This invention relates to apparatus for treating metal articles.

In cleaning, polishing, hardening or otherwise treating the surfaces of metal articles by a stream 5 of abrasive particles, the articles preferably should be so manipulated that all or the predetermined portions or surfaces are exposed for treatment and, preferably, the surfaces should be exposed for predetermined periods. Where the articles to be treated are relatively small and rugged, and are suitably shaped, they can be conveniently presented for treatment in various types of tumbling apparatus. the articles are of irregular shape or are fragile, they cannot be satisfactorily tumbled. Furthermore, where they are hollow or are irregularly shaped, it is necessary to manipulate them for treatment in a predetermined manner so that the insldesurfaces of cavities and depressions and for treatment.

According to the present invention, the article to be treated is rotated within oppositely directed streams of abrasive having a fan-like impingement pattern, the streams being so arranged and directed as to impinge the article exteriorly as well as interlorly so as to effectively clean and treat the irregularly shaped article. The streams of abrasive are projected at cleaning and treating velocities by means of two or more abrasive throwing wheels which are so arranged and operated with respect to the conveyor mechanism that efficient and thorough cleaning and treating of the article results. After sufficient treatment, the article is carried out of the stream and is manipulated to dump the treating material from the interior of the-article or from any cavities or de-' posited by means of a charging mechanism. The

rack includes spaced rolls on which the article is supported and which are driven to rotate the article relative to the rack. The rack is driven in such a way that the article is exposed to the stream for a suflicient period. The apparatus is so constructed that the rack may be driven step by step and halted for a predetermined period when each article is within the stream, or it may be driven continuously to carry the article However, where the sides of projections are suitably presented through the stream. The rack carries each article out of the stream and deposits it on a dumping mechanism which tips or inverts the article to expel any treating material from the-interior or cavities of the article.

' Apparatus constructed in accordance with this invention is suitable for treating numerous types of metal articles of various shapes and sizes, such as castings, forgings and other machine and structural members. The apparatus is particularly well adapted to treat hollow metal articles, such as various housings, casings, and other articles having depressions and cavities. The apparatus may be operated continuously and substantially automatically and requires a minimum of attention. The movement of the articles and the timing of each operation are positively controlled and may be adjusted to suit various working conditions. The apparatus as disclosed is suitable for handling articles of various shapes and sizes without requiring any change or replacement of any of the parts.

One of the objects of my invention is to provide an improved apparatus for cleaning and treating hollow metal articles and metal articles having depressions and cavities that cannot readily be treated in a tumbling mill.

Another object of this invention is to provide an improved apparatus for treating, polishing, hardening and cleaning metallic articles continuously with a minimum of hand labor and low cost, and which is furthermore flexible in service and is, adapted to efficiently handle articles of different shapes and sizes.

Various other features, objects and advantages of theinvention will be apparent from the following particular description and from an inspec tion 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 advantages, and the manner in which it may be carried out, may be better understood by referring to the folldwing description taken in connection with the accompanying drawings forming a part thereof, in which:

Fig. 1 is an end elevational view of one form of apparatus suitable for carrying out the invention;

Fig. 2 is an enlarged fragmentary, front elevational view of the apparatus shown in Fig. 1, this view illustrating certain features of the construction in more detail;

Fig. 3 is an enlarged fragmentary cross secof the dumping mechanism, this view being taken along line 66 of Fig. 3;

Fig. 7 is an enlarged fragmentary cross sectional view showing certain details of the construction, this view being taken along line '|--'I of Fig. 6; and

Fig. 8 is an enlarged fragmentary cross sectional view taken alongline 8--8 of Fig. 3.

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 per mit. 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 disclosures of the invention are made for purposes of explanation, but it will'be understood that the details may be modified in various respects without departure lfrom the broad aspect of the invention.

Referring now particularly to Figs. 1, 2, 3 and 4, there is shown a housing I having a charging vestibule 2, a treating chamber 3 and a discharging vestibule 4. Disposed in the treating chamber is a conveyor 5 (hereinafter more fully described), adapted to carry the articles to be treated from the charging vestibule 2 into position to be treated and thereafter, to deposit the treated articles in the discharging chamber 4.

One or more abrasive projectors A and B are disposed in position to project streams of abrasive a and 12 into the chamber 3 to treat the articles carried by the conveyor 5. Each abrasive projector comprises a rotatable abrasive throwing wheel 6, provided with means for controlling the direction of flight of the thrown abrasive.

Each wheel 6 comprises generally a plurality of spaced throwing blades l extending in a generally radial direction from the periphery of the wheel inwardly short of the center to define a generally central space H. Positioned within the central space I l and fixed to rotate with the throwing blades I0 is an impeller I2 having a plurality of radially arranged vanes l3. A tubular control member [4 surrounds the impeller l2 and is provided with an outlet opening l5. The control member [4 is mounted so as to be stationary relative to the impeller l2 and throwing blades II). but may be adjusted for the purpose of defining the direction of flight of the thrown abrasive. The throwing blades l0 may be secured to and carried by a pair of spaced side plates [6 and I1 secured together and carried on a hub 11' which is mounted on a shaft l8 rotatable in bearings I9 fixed to or adjacent to the top wall of the housing 1. Each' wheel may be rotated by a motor 20 connected to a suitable drive such as belt drive 2i to the shaft IS. The tubular control member l4 extends through an opening 23 v in the side plate of the wheel.

Each wheel 6 may be supplied with abrasive through a .feed pipe 22 which extends into the control member and which feeds the abrasive into the path of rotation of the impeller vanes l3. The abrasive may be contained in a storage hopper 30 connected with the two feed pipes 22 shown by conduits 3| and 32 respectively, supplying

feed hoppers

33 and 34 adjacent the receiving end of the feed. pipes 22.

Upon energization of the motor 20, the impeller i2 and throwing blades ill, together with the side plates I6 and I1 rotate together as a unit, the control member I4 being held stationary. Abrasive is supplied to the impeller l2 through the feed pipe 22 and is hurled by the impeller l2 through the outlet opening l and deposited in the path of the blades Ill. The abrasive is urged along the leading faces of the blades i0, and is pro'jectedfrom the blades adjacent the periphery of the wheel by combined centrifugal and rotary forces. The abrasive is projected from the wheel 8 at high velocity in a fan-like stream whose spread, direction of movement, and impingement pattern are predetermined by the control member l4. Thus an elongated impingement pattern is produced in a plane disposed below the wheel 6 and generally parallel to the axis of rotation of the wheel. The stream may extend over a considerable range of angularity, depending upon the structure and operation of the wheel. The direction of the stream may be adjusted by adjusting the clock-dial position of the outlet opening about the axis of rotation of the wheel, and the size and shape of the impingement pattern is controlled by the size and peripheral extent of the opening l5 in the control member.

Although the term "abrasive is used herein to designate the treating material, the term is intended to include all suitable material, such for example, as cracked steel grit, smooth steel shot, quartz sand or other materials suitable for cleaning, polishing, smoothing, hardeningor otherwise modifying the surface characteristics of the article to be treated.

Each wheel 6 is mounted in position to project a stream of abrasive in a generally downward direction into the treating chamber 3, a suitable opening 9 being provided in the top wall of the housing to accommodate the stream of abrasive fired by the wheel. If desired each wheel 6 may be mounted so that at least a portion of the wheel projects into the chamber 3 and thus the wheel may be located nearer. the work piece. A suitable housing 25 or housings may be provided for each wheel.

An important feature ofthis invention comprises the arrangement of the abrasive-throwing wheels and conveyor mechanism, which operate in a manner to uniformly clean and treat the irregular cavities and projections of the article. It will be noted, for example, by referring to Fig. 4, that the wheels A and B are arranged to rotate in opposite directions so as to hurl the abrasive at high velocity into the cavities of the article C being treated as well as against the outside surface thereof.

The bottom wall 40 of the housing I may be formed as a hopper for collecting spent abrasive and a conduit 4! maybe connected thereto for conveying the spent abrasive to a housing 45, enclosing an elevator 42. A suitable source of energy such as motor 43 connected by a suitable drive 44 to the elevator 42 may be provided to operate an elevator. Upon energization of the motor 43, the elevator-42 lifts the abrasive from the lowermost portion of the elevator housing portion of the elevator housing 45 may be disposed in a pit below the level of the floor on which the apparatus is located.

The charging vestibule 2 preferably includes an inclined floor 50 extending through the side wall of the housing. and terminating adjacent the conveyor 5. The vestibule 2 may be closed by one or more curtains 5I to prevent flying abrasive particles from passing out of the housing. Rotatably mounted principally in the charging vestibule 2 is a pair of spaced and generally parallel heads 52 carried on a shaft 53. The heads 52 have circumferentially arranged, in-

wardly projecting studs 54 which cooperate to form a loading rack adapted to supply the articles to be treated to the conveyor 5 at the proper time. The studs 54 on each head are disposed in suitable relation to the studs on the other head to engage a work piece.

The shaft 53 is rotatably' mounted in bearings 55 and 56 and may be rotated from a suitable source of power such as a motor 50. The motor 60 may be connected, through a suitable drive, such as belt drive Ii I, to a speed reducer 62, which in turn drives a shaft 63. The shaft 63 may carry a sprocket 04 and a chain 65 may be trained.

over the sprocket 54 and over a second sprocket 56 fixedly secured on the shaft 53.

Upon energization of the motor 60, it'operates through the several connected drives to rotate the shaft 53 and the heads 52 are rotated together to carry successive pairs of studs 54 in the position to receive and engage one of the articles to be treated. The articles to be treated are disposed on the floor 50 and are successively rolled into position between two adjacent studs which control the movement of the article 0. As the heads 52 rotate, the article c is permitted to move by gravity or is positively urged to the left (as viewed in Fig. 3) and is deposited on the conveyor.

prising casing d of somewhat lesser diameter, in

orderto illustrate how the apparatus handles articles of various sizes without any changes or substitution of parts.

The conveyor (Fig. 3) is mountedin position,

to receive a casing c from the end of the floor 50.. The conveyor 5 is adapted to receive a casing c from the charging mechanism, carry it into the paths of the abrasive streams a and b fired by the wheels A and B- respectively, maintain the casing in the streams a and b for sufficient time to properly treat the casing, rotate the casing while in the streams a and b and finally deliver the casing c to discharging mechanism in the discharge vestibule 4. The conveyor 5 (Fig. 4) may be formed as a rack whichis mounted for rotation about a fixed axis within "theehamber 3. The conveyor 5 may comprise awpair of spaced heads which support therebetween aplurality of spaced and circumferen- 7 tially arranged shafts II. Each head may'comprise one or more head plates 10. Each shaft II carries a generally cylindrical roll 12 which may extend throughout a portion or substantially the entire length of the shaft II.

Each shaft II preferably is rotatably mounted at each end in a bearing I3 carried by the head plates 10, each head being mounted on a hub 15, the head plates I0 being secured to the hub 15 in a suitable manner, as by rivets "It. The hubs 15 are fixedly secured on a supporting shaft I'l, as by a pin 18. The shaft ll may extend out of the housing and may be rotatably supported at each end thereof in bearings 19 mounted on brackets A plurality of stationary baffles 82 may be provided which overlap and cooperate with the plates of each head for preventing the egress of flying abrasive from the housing I. The shaft II may be protected from the wearing effects of the abrasive by a'plurality of protective sleeves 83, which also may serve to position the roll 12. Additional protective sleeves 84 may be provided adjacent the ends of each shaft II. The rolls I2 and the

protective sleeves

83 and 84 may be formed of suitable resilient material which is not subject to undue wear by the abrasive material, such as rubber or rubber fabric.

The conveyor 5 may be driven from the shaft 63 and may be given a step-by-step rotation for a purpose which will hereinafter appear. Fixedly secured on the shaft 63 (Fig. 5) is a lever 90 connected by a pin 9I" .to one section 92 of a connecting rod 93 of variable length. A second section 94 is connected to the first section 92 by a shank 95 having an enlarged head 96 slidable in a recess 91 in the first section 92. A spring 98 may be disposed in the recess 91 and

urge sections

92 and 94 apart and an air entry and exhaust port 89 may be provided for permitting relatively free movement of the head 95 in the recess 95. Av

bushing 88 may be secured in the end of section 92 to prevent expulsion of the head 96 from the section 92.

The section 94 may be connected by a pin 99 to a lever I00 freely rotatable on the shaft Ill, and a dog IOI may be pivotably carried by the pin 99. The dog IOI is adapted to cooperate with a rotatable plate I03 rigidly secured to the shaft 11 and formed with spaced notches I02. The dog IOI may be pressed into engagement with the notches I02 by a coil tension spring IOIa. secured to the section '94 and to a lug IOIb projecting from the dog IOI as shown in Fig. 5. Mounted adjacent plate I03 is a stopdog I05 carried on a pin I06 rotatable in a bearing I01. A compression spring I08 is anchored to a bracket I09 and is adapted to rotate the stop dog I05 in a clockwise direction (as viewed in Fig. 5) for maintaining the dog I05 resiliently in position to engage successively in the notches I02.

Upon rotation of the shaft 63, the lever 90 is rotated and imparts a reciprocating and swinging motion to the connecting rod 93. This effects a toggle movement of the connecting rod 93 and lever I00 which movement causes the dog IN to engage in' one of the notches I02 and rotate the plate I03 one-quarter of a turn. At the end of this movement the stop dog I05 engages in one of the notches I02 and prevents reverse movement of the plate I03. Upon further rotation of the shaft 33, the connecting rod 94 is returned toward its initial position and retracts the dog IOI from the notch I02 and moves it into position to drop'into the next succeeding notch I02; This action causes the conveyor 5 to rotate in a step-by-step movement, one-quarter of a turn upon each revolution of the shaft 63.

The connecting rod 93 is adapted to shorten upon the downward stroke of the section 92 and the lost motion between the

sections

92 and 94 permits the connecting rod 93 to perform the necessary movement to impart the desired partial rotation to the plate I03. If desired, this mechanism may be designed so that, upon downward movement of the section 92, there is no substantial movement of the section 94, until considerable resistance is built up by the spring 98. Thus, when the lower end of the connecting rod 93 moves to the right it imparts unaccelerated partial rotation to the plate I03.

The shafts H are continually rotated in a clockwise direction (as viewed in Figs. 1 and 3) in order to rotate the casing c on the conveyor 5 as will hereinafter appear. A suitable source of energy, such as a motor I20, drives a pulley I2I, and a belt I22 is trained over the pulley I2I and also over pulleys I23 carried on the ends of the shafts 1|. A suitable tension device may be provided for tensioning the belt I22 and maintaining it in engagement with at least the uppermost of the pulleys I23. The tension device may include an idler pulley I24 rotatably carried on a lever I25 mounted on a pivot I26 and provided with a counterweight I21. Upon energization of the motor I20 the belt I22 is driven in suitable direction and rotates at least the uppermost of shafts 1I during their movement, thus rotating the corresponding rolls 12 which carry one of the casings 0.

Referring to Figs. 3, 6 and '1 suitable unloading mechanism may be disposed in the discharge vestibule for receiving treated casings from the conveyor, tipping the casings to remove abrasive from the interior and conveying the casings out of the apparatus. Extending into the treating chamber 3 and adjacent to the conveyor 5 is an inclined floor I which receives the articles or casings c as they are dropped out of the conveyor. The floor I is provided with an upstanding guide flange I42 for guiding the casing as it rolls down the inclined floor I. The outer end of the floor MI is provided with a cutout portion which defines a ledge I43 of sufficient width to support only one end of the casing or article, as indicated more particularly in Fig. 8.

Slidably mounted under the narrowed portion I43 of the floor is an arm I having an upstanding flange I 44 adapted, when the arm I45 is extended (as shown in Fig. 6), to support the overhanging portion of the casing c and prevent it from falling off the floor portion' I43. The arm I45 extends through an opening I46 in the wall of the discharging vestibule and is supported by a plurality of suitably positioned rolls I41. When the arm I45 is retracted (to the left as viewed in Fig. 6) the casing c is unsupported at its right and consequently tilts and drops off the floor I43.

The arm I 45 is periodically reciprocated by a suitable mechanism which may be driven from the shaft 63 (Fig. 5). The shaft 63 carries a sprocket I49 and a chain I50 is trained over the sprocket I49 and over a sprocket I5I, fixed on a shaft I52 mounted in earings I53 and I54 adjacent the discharge ves ibule. Fixed on the shaft I52 is a cam I55 having a groove I56 receiving a follower I51 carried on a lever I58. The lever I 59 is pivotally connected to a pin I59 and is adapted to oscillate about the pin when the shaft I52 rotates the cam I55. The lever I58 carries on its free end a pin I60 received in a notch I6I formed in a lug I62 integral with the bracket I45.- When the lever I58 is oscillated the pin I60 cooperates with the lug I62 to reciprocate the arm Disposed below the floor I43 in a position to receive a casing c is roller conveyor I65, including a series of rolls I66 carried on shafts I61 journaled in bearings I68. The rolls are relatively closely spaced and form an inclined supporting surface extending through an outlet opening I69. A casing c deposited on the rolls I66 in upside down position will roll therealong under the force of gravity and out of the discharge vestibule 4. A suitably shaped wall I10 may be provided adjacent the dumping mechanism and conveyor I for insuring that the casings fall on the latter in the proper position.

The operation of the apparatus is as follows: The motors 20 are energized to drive the projectors A and B, the motor 60 is energized to drive the conveyor 5 and the dumping mechanism, and the motor I20 is energized to effect rotation of the rolls 12. A casing c or other work piece is deposited on the inclined floor 50 of the charging vestibule. The heads 52 rotate together and the studs 54 are carried around and permit the work piece 0 to roll along the floor 50 into a position between two successive studs. Further rotation of the heads 52 causes the studs 54 to engage the casing 0. than the distance between two successive studs, they carry it in a somewhat arcuate movement into position to be engaged by the conveyor 5. In the event that the casing c is of smaller diameter than the distance between successive studs, the casing 0 will roll along the floor 50 at a speed controlled by the studs 54. The casing is thus brought to and deposited on the conveyor 5 at the proper time to be engaged by two successive rolls 12, as the conveyor 5 rotates.

When the heads 52 have deposited the casing c on the conveyor, the latter carries the casing 0 into a position wherein it is struck by abrasive streams a and b. The conveyor 5 is moved with a step-by-step movement and is halted during a I predetermined interval to retain the casing in the abrasive streams a and b for a predetermined period. The rolls H are continuously rotated in the same direction during at least the period while the casing c is supported thereby and thus causes the casing c to roll thereon about the central axis oi.v the casing c. This rotation brings all portions of the surfaces of the casing c successively into position to be struck by the treating particles.

It is important to note that projectors A and B rotate in opposite directions and are so arranged relatively to the conveyor 5 that one of the streams, for example, stream a strikes against the inside surface of the casing c and the other of the stream, for example, stream b, strikes against the outer surface of the casing c, as illustrated in Fig. 4. Thus, all portions of the surface are thoroughly and evenly treated.

After a predetermined period, as determined by the step-by-step driving mechanism, the conveyor is given further partial rotation and deposits the casing c on the floor I. The casing c rolls along the floor I and onto the narrowed floor portion I43. The arm I45 is operated as above described and is in its extended position (to the right as viewed in, Fig. 6) when the casing 0 rolls into the narrowed portion I 43. The

If the casing is of greater diameter 5 arm I45 is then retracted so that the casing is an angle of approximately and falls onto the rolls I66. The inverting of the casing c dumps out the spent abrasive which remains in the casing and, when the casing is discharged from the apparatus it is entirely clean and ready for use or further treatment. The casing rolls along the conveyor I 65 and out of the apparatus and is then ready for use or further treatment.

The present invention provides a method whereby hollow articles, or articles having cavities of substantial size or depth, can be treated completely and effectively. The method is continuous and substantially automatic and requires little attention on the partof an operator. The articles are fully and completely treated both inside and outside and the abrasive which may collect in the cavities or interior is removed and the articles are discharged from the apparatus in clean condition.

The apparatus is continuous in operation and it is not necessary to shut down for the purpose of supplying articles to the apparatus or removing them therefrom. The entire apparatus is substantially automatic and the apparatus may be installed as a component part or complete apparatus for treating various articles. The apparatus is well adapted for treating castings and forgings of various sizes and considerable variation in shape successively in a single installation without changing any of the apparatus.

The apparatus is rugged in construction and eflicient in operation and the portions which receive considerable wear due to being struck by abrasive particles are suitably protected and may be readily removed and replaced when worn. The treating chamber may be effectively enclosed and thus operators are protected from flying abrasive.

While certain novel features of the invention,

have been disclosed herein 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 blast cleaning hollow metal articles including in combination, a housing, means for projecting a stream of abrasive particles into said housing, a conveyor for conveying an article to be cleaned into and out of the path tatably mounted on said frame adapted to support an article to be cleaned between adjacent ,rolls, means for rotating said rolls so as to present the various surfaces of the article to the abrasive stream, and putomatic means for intermittently rotating said roll-supporting frame to convey the articles supported thereon into and out of said abrasive stream.

3. Apparatus for blast cleaning metal articles including, means for projecting a stream of abrasive particles, an article carrying frame having a plurality of generally parallel supporting eleelement constitutes with the succeeding element an article support, means for rotating said elements on said frame whereby to rotate an article supported thereby, and means for rotating said frame about a horizontal axis whereby an article carried on said supporting elements is advanced through said abrasive stream and simultaneously rotated therein.

4. Apparatus for blast cleaning metal articles including, means for projecting a stream of abrasive particles, a frame, means mounting said frame for rotational movement about a horizontal axis, means including spaced rolls rotatably mounted in said frame for rotatably supporting an article on said frame, means driving said frame whereby an article deposited on an ascending portion of said frame is carried through said stream, and means driving said rolls for rotating said article in the stream.

5. Apparatus for blast cleaning metal articles including, means for projecting a stream of abrasive particles, a rotatable frame for supporting and carrying an article to be treated through said stream, means driving said frame, means for rotating said article on said frame, loading means for depositing an article on said frame, said loading means including a rotatable member, projections extending from said member each operative to engage an article to be cleaned and advance the same when said member is rotated, and driving means for rotating said member synchronized with said frame driving means whereby said article is deposited on said frame at a predetermined point in the movement thereof.

6. Apparatus for blast cleaning hollow metal articles including, a housing, means for projecting a stream of abrasive particles, a frame for carrying an article-to be treated through said stream, means driving said frame, means for rotating said article on said frame, means for receiving said article from said frame, means for tipping said article to dump spent abrasive from the interior thereof, and means active upon actuation of said tipping means for conveying said article from said housing.

7. Apparatus for blast cleaning metal articles including, means for projecting a stream of abrasive particles, a frame for carrying an article to be treated through said stream, means driving said frame, means for rotating said article on said frame, means for receiving said article from said frame, means for dumping said article, and actuating means .for said dumping means synchronized with said frame driving means.

8. Apparatus for blast cleaning metal articles including, means for projecting a stream of abrasive particles, a frame including spaced articlecarrying portions, means for rotating said frame to advance said article-carrying portions successively into said stream, a loading mechanism including means for releasing an article to deposit said article on said frame, and means for driving said loading mechanism in synchronism with saidframe whereby articles are presented successively to said frame in position to be successively engaged by the article-carrying portions thereof respectively. 9. Apparatus for blast cleaning metal article including, means for projecting a stream of abrasive particles, a frame having a plurality of spaced rolls thereon defining article-carrying portions, means for rotating said frame to bring said article-carrying portions into article-receiving position successively, a rotatable delivery rack ments arranged in spaced relation whereby each adapted to deliver articles to said frame and having a plurality oi article-supporting portions, and means for rotating said delivery rack in synchronism-with said frame whereby articles engaged by said article-supporting portions are delivered to said frame in position to be engaged by the articlescarrying portions thereof as the latter advance into article-receiving position.

10. Apparatus for blast cleaning metal articles including. a centrifugal abrasive throwing wheel for projecting a stream of abrasive particles at blasting velocities, a movable conveyor for supporting and carrying an article to be treated through said stream, means for driving said conveyor, means for rotating said article on said conveyor, loading means for depositing an article on said conveyor, said loading means including a rotatable member, projections extending from said member each operative to engage an article to be treated and advance the same when said member is rotated, and driving means for rotating said member synchronized with said conveyor driving means whereby said article is deposited on said conveyor at a predetermined point in the movement thereof.

11. Apparatus for blast cleaning metal articles including, a centrifugal abrasive throwing wheel for projecting a stream of abrasive particles, a conveyor for carrying an article to be treated through said stream, means for driving said conveyor, a movable support for receiving said article from said conveyor, and actuating means for manipulating said movable support to dump the article supported thereby, said actuating means being synchronized with said conveyor driving means.

12. Apparatus for blast cleaning metal articles including, an abrasive throwing wheel for projecting a stream of abrasive particles, a movable conveyor having article-retaining portions, means for moving said conveyor to bring said articleretaining portions into article receiving position successively, a rotatable delivery rack adapted to deliver articles to said conveyor and having a plurality of article-supporting portions, and means for rotating said delivery rack in synchronism with the movement of said conveyor whereby articles engaged by said article-supporting portions are delivered to said conveyor in position to be engaged by the article-retaining portions thereof as the latter advance into articlereceiving position.

DAVID C. TURNBULL.