US2224153A - Abrasive throwing machine - Google Patents

Description

1 1940- J. E. GUENDLING ABRASIVE THROW-1N6 MACHINE 4 Sheets-Sheet 1 Filed March 22, 1938 INVENTOR Joim E. fiaenalig ATTORNEY Dec. 10, 1940. J, U N 2,224,153

ABRASIVE THROWING MACHINE Filed Mal-ch22, 1958 4 Sheets-Sheet 2 INVENTOR E John If fiumali g 1 BY m 1 4'5 ATTORNEY Dec. 10, 1940. GUENDUNG 2,224,153

ABRASIVE THROWING MACHINE Filed March 22, 1938 4 Shee1'Is- Sheet 3 ,4; ATTORNEY Dec. 10, 1940. J. E. GUENDLING ABRASIVE THROWING' MACHINE Filoddlaroh 22, I938 4 Sheets-Sheet 4 MA ww n T m Mm K m Ms Patented Dec. 10, 1940,;

ABRASIVE THROWING MACHINE John E. Guendling, South Bend, Ind., assignor to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application March 22, 1938, Serial No. 197,339

11 Claims.

This invention relates to abrasive throwing machines and more particularly to a throwing wheel of the centrifugal type having improved means for controlling the direction of flight of the thrown abrasive.

According to the invention, the machine comprises a rotor having a plurality of throwing blades extending from the periphery of the rotor to points inwardly short of the axis of rotation of the wheel to provide a central space, the blades being suitably mounted for rotation about the axis of the rotor. Abrasive is fed to the rotating blades through a control member extending into the space provided centrally of the rotor'and having an abrasive discharge outlet in the tubular side wall thereof. An impel1er comprising one or more vanes which extend into the tubular control member and is mounted to rotate with the blades to throw abrasive through the discharge outlet in the control member and into the path of rotation of the blades. The control member and impeller are so shaped and positioned relative to each other and to the other portions of the rotor as to minimize the entry of uncontrolled abrasive material into the path of rotation of the blades, thus reducing the possibility of clogging or undue wear.

In an illustrative embodiment of the invention the control member comprises a generally tubular side wall portion which is open at one end to permit the entry of abrasive and closed at the other end as by an end wall. A stud extends from the end wall into the tubular side wall portion but is spaced therefrom to permit the impeller to run in the space therebetween. The stud provides a means by which the control member may be adjustably supported. The stud may be tubular in form and may be connected to the discharge end of the feed pipeso that the abrasive may pass into the tubular stud and escape therefrom through one or more openings provided therein. The impeller comprises a member having a plurality of spaced, generally radial vanes positioned between the stud and the tubular side wall portion of the control member and a portion which is seouredto the feed side of the rotor to securely and rigidly support the impeller with respect to the rotor blades.

An object of the invention is the provision of an abrasive throwing machine provided with a Another object of the invention is to provide.

an abrasive throwing wheel of the type having rotating blades and a relatively fixed control member for controlling the supply of abrasive material to the blades wherein spillage of the abrasive is minimized and wherein any abrasive which is not deposited on the blades is removed 5 from the interior of the wheel.

. Still another object of the invention is the provision of an abrasive throwing wheel of the type having rotating vblades and an impeller rotatable therewith wherein the impeller is firmly and securely mounted in a novel manner. for rotation with the blades. 7

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 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 following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is a fragmentary, side elevational view of an abrasive throwing rotor constructed in accordance with the invention, having the improved device for controlling the direction of discharge of the thrown abrasive incorporated therewith;

Fig. 2 is a transverse cross-sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is a longitudinal cross-sectional view through the machine taken along line 3-3 of Fig. 2;

Fig. 4 is a fragmentary cross-sectional view taken along line 4-4 of Fig. 2 and through the improved control device associated with the abrasive throwing rotor;

Fig. 5 is an exploded perspective view of certain operative elements'forming the control device, certain parts being broken away to illustrate more clearly certain features of the construction;

Fig. 6 is a fragmentary cross-sectional view of the central portion of the rotor and showing an alternative form of control member;

Fig. 7 is a. fragmentary cross-sectional view the central portion of the wheel and showing an alternative form of impeller;- 1

Fig, 10 is a fragmentary cross-sectional view taken along line Ill-40 of Fig. 9;

Fig. 11 is a fragmentary side elevational view of the discharge end of the feed pipe and the tubular control member, showing alternative means which may be employed for securing these parts together, certain parts being shown in section to more clearly illustrate the construction; and! Fig. 12 is a cross-sectional view taken along line l2--l2 of Fi 11.

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.

The improved'device for obtaining more accu-.

rate directional control of the thrown particles may be associated with any suitable rotor adapted to be driven at high speed and provided with suitably arranged abrasive throwing blades. Referring particularly to Figs. 1, 2 and 3, there is shown for purposes of illustration one form of rotor which may be used, comprising a rotor disc or side wall member I which is operatively secured to a high speed drive shaft 6. To give strength and sturdiness to the construction a hub member I is suitably splined or otherwise secured to the drive shaft 8 and is secured by bolts: B or other means to the rotor disc I.

V One or more abrasive throwing blades b are suitably mounted on the rotor disc i and extend inwardly short of the axis of rotation of the rotor whereby their inner ends define a central space a. To provide additional support for the blades b, and to provide a support to which the rotating impeller, hereafter described, may be secured, a side wall member or disc 2 having a central opening therein may be provided. The disc member 2 may be held in substantially parallel, fixed, spaced relationship with the rotor disc i by any suitable means, For purpose of illustration, there is shown a series of spaced studs 3 having shoulders 4 thereon, which abut the inside face of the adjacent side wall plates i and 2 and heads 5, which are burnished or otherwise suitably secured to the side wall plates 8 and 2.

The blades b may be held in fixed, suspended position between the side wall plates by providing paired radially extending grooves in the side wall plates l and 2 within which the side edges of the blades seat. There is shown for purposes of illustration a throwing wheel having a series of eight, spaced, radially arranged blades b, each comprising a throwing surface or bottom wall portion 70 and flange or side wall portions H extending in the direction of rotation of the wheel to confinethe moving abradant or comminuted material on the working face ill of the blade b and between the side flange ii thereof. The blades b may be secured in place by set screws 90 extending through one of the side plates and entering notches or depressions Si in the blades b.

To insure smooth pick-up of the abradant material at the inner end of the blade b, the inner end of the blade b is formedwith a relatively thin edge 12 which may be produced by roundin chamfering, or otherwise shaping the rear face of the blade b at the inner end thereof, as shown at I3 in Fig. 3.

Toobtain a high degree of directional control of the thrown material and toinsure a smooth movement of substantially all of the abradant material onto the inner end of the blade during a predetermined limited arc of rotation thereof, a tubular control member is provided. As shown more particularly in Figs. 2, 3 and 5, the tubular control member or control sleeve 50 comprises a tubular side wall i5 which is generally cylindrical in exterior and interior outline. The inside surface of wall 15 may be slightly spiralled in crosssectional contour, as indicated in Fig. 3, thereby aiding the feeding of abradant and preventing choking. The inner end of the tubular side wall I5 may be entirely closed by an end wall It, shown more particularly in Figs. 2 and 5.

A discharge outlet is provided in the side wall L5. This outlet may comprise a single opening adjacent the path of rotation of the inner ends of the throwing blades b or may be constituted by a plurality of suitably disposed openings, such as shown in Patents Nos. 2,077,635 and 2,077,636, which may be so dimensioned and arranged as to provide an abrasive stream of substantially uniform distribution of abrasive, or which may impart to the stream any other desired distribution characteristic.

The tubular control member extends into the central space a defined by the inner ends of the blades b of the rotor with the closed end It positioned adjacent the rear rotor disc i. Preferably, the free edge I! of the tubular side wall l extends beyond the adjacent side flange H of the blades and, as shown in Fig. 2, may com-en iently extend beyond the outside face of the side wall plate 2. The tubular control member does not rotate with the rotor but remains in a stantially fixed or controlled position during op eration.

The clearance between the inner ends of the blades b and the side wall i5 of the tubular control member should be small, and preferably, only suchclearance is provided as is necessary to insure safe operation of the rapidly rotating rotor with respect to the stationary control sleeve.

The control sleeve may be mounted in fixed normally stationary position by any suitable means. Referring now to Figs. 2 and 5, such mounting means may comprise a hollow stud it which projects inwardly and 'is secured to the end wall it of the control sleeve, sufficient space being provided between the hollow stud l8 and the inside contour of the tubular side wall iii of the control sleeve to permit satisfactory rotation and operation of impeller vanes (hereinafter described) of suitable size therebetween.

The abrasive is fed into the hollow stud l8 and escapes through one or more discharge openings 09' therein, the openings it being defined by suitable legs or straps l9 forming a part of the control sleeve supporting stud. The supporting stud l8 may be suitably secured to the end of and supported by a supply pipe 20 of such length and of such diameter as to supply the required amount of the abradant material to be thrown from the wheel.

A suitable supply hopper or funnel 2!, which may be secured to the upper end of the feed pipe 20, is so shaped as to assist the movement of the material into the feed pipe 20. In the event the tubular control sleeve is mounted on the end of the supply pipe 20, it is necessary that the supply pipe 20 be securely mounted in fixed position, so that no movement of the tubular control sleeve during operation of the wheel will There is illustrated in Figs. 1 and 2 one form of supply. pipe and control sleeve support which may be used. A foot plate 22, which may integrally be secured to the feed pipe 20 by a supporting web 23, is arranged to rest on a supporting bracket 30. The supporting bracket may be provided with a flange 29 secured as by apair of spaced bolts 28 to an upwardly extending flange 21 on another bracket 20', having a foot portion 25 which rests upon a fixed frame member or abutment 24 and is secured thereto as by a bolt or bolts 26.

The downwardly extending flange portion 29 of the supporting bracket to may be provided with a slot 29' to receive the bolts 28 and which permits shifting of the feed pipe as and the control sleeve mounted thereon axially with respect to the central space a of the rotor. Likewise, the foot portion 22 associated with the feed pipe 20 may also be provided with a slot 32 through which the bolt 3!! extends to permit lateral shifting of the feed pipe 2% and the control sleeve mounted on the end thereof to properly center the control sleeve within the central space a of the rotor. The flange portion 21! oi the second bracket 38' may also be provided with vertically extending slots through which the bolts 28 extend to permit vertical adjustment of the feed pipe 20 and the control sleeve attached to the inner end thereof. Thus, three adjustments are provided to permit proper positioning and centering of the control sleeve within the central space a of the rotor.

The supply pipe 20 and the control sleeve may beheld in fixed position by proper adjustment and tightening of the bolts 28. and M. It is appreciated that numerous different types of adjustable supports may be provided for supporting the feed pipe 20 and the control sleeve associated therewith.

To lessen the weight imposed upon the supporting bracket 20, the supply funnel or hopper 2| may be independently supported by an arm 33' extending upwardly from the foot portion 25, which arm is secured to a bracket 34 as by bolts 34, the bracket 24 being suitably attached to the supply funnel or hopper 2i.

A leakproof seal between the inner end of the supply pipe 20 and the hollow supporting stud projections occur which might impede the normal smooth flow of the abrading material.

To further insure the seal-tight'flt between these parts, ashoulder 31 may be provided on the interior of the feed pipe 20 against which abuts the free end 29 of the fitting 36. Similarly, a shoulder 28 is provided on the hollow stud it against which abuts the free end 40' of the feed pipe .20. The control sleeve may be locked to the inner end of the feed pipe 2|] by a spring collar or. clip it provided with inwardly projecting studs 44. The hollow boss 25 provided on the innerend of the feed pipe-10 15 provided with corresponding openings or apertures ll through which the studs 44 may extend.

Corresponding apertures or openings l2 may be provided with the fitting 38 forming a part of the hollow stud l8 on the control sleeve. The studs 44 are of sufilcient length to extend through the apertures ll, the boss and into the apertures 42 oi the fitting 36. v

To permit the desired orientation of the discharge outlet 0 1n the tubular control sleeve, a plurality of spaced apertures 42 may be provided in the fitting 35 so as to permit any desired rotative adjustment of the control sleeve with respect to the feed pipe 20. Thus, the discharge outlet 0 in the control sleeve may be arranged in any clock dial position relatively to the axis of the rotor so,

as from the apertures in which they are seated,

rotating the control sleeve the desired amount so as to permit the studs M and the clip 35 to snap into the selected apertures 62111 the fitting 3t of the hollow stud associated with the control sleeve. An impeller is provided to forcibly project the abradant out through the discharge outlet 0 in the control sleeve and in substantially the same direction as the direction of rotation of the blades b and at a velocity only slightly less than the angular speed of rotation of the inner ends of the blades. As shown more particularly in Figs. 2, 3 and 5, the impeller 60 comprises a pair of spaced rings or side wall plates 5i'and 52 between which are arranged a series of spaced abrasive throwing vanes 53. Preferably, there is a vane 53 for each of the abrasive throwing blades 1) which are arranged so that each vane is positioned slightly in advance of the corresponding blade in the direction of rotation, as illustrated in Fig. 3. The vanes 53 are mounted for rotation within the control sleeve in the space between the side wall i5 and the hollow stud i8, whereby abrasive which is V forced through the openings I9 is deposited in a path of the vanes 53 and thrown out through the discharge opening 0 of the control sleeve.

The vanes 53 and connected side plates 5| and 52 are securely mounted for rotation withthe throwing blades b. A sleeve portion 59 extends out through the opening 2' in the side plate 2 and is attached to or preferably integral with a rim portion 58 having a mounting ring or flange 55.

The flange 55 is attached to the outer wall of the side plate 2 as by bolts or screws 51 extending through openings 56 in the flange 55. The flange 55 may be set back slightly so that the rim' 5. is set out from the face of the side plate 2 and accommodates the open end of the side wall l5 of the control sleeve.

The sleeve portion 59 of the impeller is spaced from the edge of the opening 2' in the side plate 2 to provide a space to accommodate the side wall I5 of the control member 50, this space, however, being preferably only sufllciently large to permit the proper clearance, thus preventing the accumulation of abradant material therein. The sleeve portion 59 is provided with a shoulder 54 to accommodate the correspondingly shaped portion l5 of the control sleeve 50.

In order to permit the escape or spillage of any abradant which enters the space a defined by the inner ends of the blades b and which is not deposited in the path of the blades b, one or more spillage openings 61 .are provided. In the present embodiment the spillage openings ii are formed in the rim portion 58 of theimpeller and take the form of elongated slots. Thus, if any abradant collects in the space a and is not deposited in'the path of the blades b, it will be ejected through the spillage openings 60. The movement oi. the vanes 53 and the blades b will agitate any abradant material sufiiciently so that it will either be picked up by the vanes 53 and thrown into the path of the blades b or will be carried to the openings BI and expelled therethrough.

The construction of the control member 50 and particularly the provision of the completely closed end wall I6, minimizes or completely prevents the leaking of abradant from the space within the side wall I5 and thus substantially all the abrasive is positively directed and is hurled through the opening and into the path of the blades b. Since the free, open end of the side wall I extends past the edges of the blades and through the side wall 2, the abrasive in the sleeve is positively directed out of the wheel and there is little possibility of leakage of abrasive into the space between the control sleeve and the blades and side plates.

The wheel may be assembled in a manner which will be apparent to those skilled in the art from an inspection of the drawings and a reading of the foregoing description. However, it should be noted that, if desired, the control sleeve, feed supply pipe and the impeller 60 can be first assembled together, and these members thereafter assembled with the remainder of the wheel. In an analogous manner, whenever repairs or adjustments are to be made, the feed pipe, control member and impeller can be removed from the wheel as a unit.

In the operation of the wheel, the shaft 6 is rotated thereby rotating the hub member I, side plates I and 2 and throwing blades b as a unit.

ply pipe 20 and through the fitting 36 and is delivered into the interior of the hollow stud I0 from which it flows through one or more of the openings l9 and into the path of movement of the vanes 53. The rotating vanes 53 carry the abradant material with them and throw it out through the opening 0 and into the path of the blades b. The material is picked up by the blades b and carried to the periphery ofthe wheel where it is hurled from the blades at the desired velocity. The other factors being equal, the direction of flight of the abrasive as it leaves the wheel is determined by the clock dial position of the opening 0. which position can be adjusted by adjusting the position of the control member 50 in the manner previously described.

Certain modifications can be made in the structure hereinbefore described without departing fromthe spirit of the invention. Referring now 1 particularly to Figs. 6, 7 and 8, there is shown an embodiment of theinvention wherein an altemative construction of control member is employed, the remaining portions of the wheel being similar in all respects to the corresponding parts illustrated in Figs. 1 to 5.

' v The wheel comprises a plurality of throwing blades I10 carried by said plates IM and I02 and suitably mounted on shaft I06 for rotation. as above described. The impeller I60 is carried on the side plate I02 and has throwing vanes I53 disposed in the space a defined by the inner ends of the blades I10, as described hereinbefore.

The feed pipe I leads to the space a and communicates with and supports a control member I50 of modified construction. The control member I50 comprises a tubular side wall H5 having an opening 0 or a plurality of openings, as disclosed in the patents above referred to. The tubular side wall member 5 is closed at'its side opposite the feed end of the wheel by an end tube I20, a fitting I36 preferably of cylindrical form being provided for this purpose. The fitting I36 preferably is formed integral with the stud M9 and is machined on its outer surface to provide a sealtight fit with a hollow boss I formed on the end of the feed tube I20. A shoulder I31 is provided on the feed pipe against which the free end I39 of the fitting I36 abuts. Similarly,

a shoulder I38 is provided on the stud I I0 against which the free end N0 of the feed pipe abuts.

A springcollar or clip H3 is provided having inwardly extending studs I54 which project through openings MI of the feed pipe I20 an enter recesses I62 in the fitting I36.

Referring now toFigs. 11 and 12 there is shown an alternative form of means'for securing the control member to the feed pipe. In this embodiment of the invention the control member can be adjusted to any one of an infinite number of positions angularly about the axis of the wheel. The control member 250 is formed in a manner generally similar to the control member but, instead of being locked to the supply pipe by a positively positioned means, is secured frictionally, whereby very close adjustments can be obtained.

In this construction the supply pipe 220 is provided with an enlarged end or boss 235 into which is telescoped a fitting or cylindrical exten-'- sion 236 of the control sleeve 250. The free end of the fitting 236 abuts a shoulder 23'! on the supit can be slightly contracted to frictionally grip the fitting 236. Lugs 2 80 are formed adjacent the ends of the split boss 235 and are provided with registering openings 28I through which a bolt 282 is extended and secured as by a nut 283. When the boss 235 is contracted slightly by tightening the nut and bolt it tightly g ips the fitting 236. It will be understood that there is a close machine-fit between the'fitting 226 and the boss 235 so that a very minute contraction of the boss I In the construction illustrated in Figs. sand 10,

the impeller comprises a plurality of vanes 353 carried between side wall members 85! and 352. The vanes and side wall members are supported 5 by a sleeve portion 359 which extends out through the opening 302' in the side wall plate 302. The sleeve portion 359 is integral with and carried by a mounting flange 355 extending substantially perpendicularly to the sleeve portion 359. The

mounting flange 355 is of substantial thickness side wall 3 l 5 of the control member 35% and which is not thrown into the path of movement of the throwing blades Bill, is discharged through the spillage ducts 36E. The movement of the vanes 353 and the blades 3W tends to agitate suchma terial and assist its movement toward the ducts.

' After the material enters the ducts it is caused to flow therethrough by the centrifugal force created by the rotation of the impeller and is forcibly ejected from the outer ends of the ducts.

It will be understood that either form of control member, either form of means for securing the control member to the supply pipe or either form of impeller may be employed with either of the forms of the remaining members of the wheel.

5 In other words, where alternative constructions are shown, either alternative'canbe employed in a wheel constructed in accordance with the invention.

From the foregoing it will be seen that the 40 present invention provides an improved abrasive throwing machine wherein uncontrolled leakage or spillage of abrasive material from the control member into the path of rotation of the blades is minimized or substantially prevented. The abrasive material is positively and efliciently delivered to the vanes of the impeller and the possibility of undue wear or clogging of the wheel is reduced to a minimum. The construction provides a simple and eflicient manner of mounting the impeller by 60 which the impeller can be securely and positively fixed relative to the throwing blades and prevented from turning or becoming displaced in such a way as to change the predetermined clearance between the rotating and stationary parts of the wheel. i

The present invention provides a structure in which the supply pipe, impeller and control member occupy a minimum of the space within the inner ends of the throwing blades and interfere to the minimum extent with the smooth and full How of abrasive material from the hopper to the throwing blades. Furthermore, the novel construction of supply pipe and control member permits a smooth unimpeded flow of abrasive material without any liability of clogging or choking.

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 7 be made by those skilled in the art without de- 1 parting from the spirit of the invention.

It is to be understood that the term abrasive,

ing action or capable of hardening or polishing the articles treated. Such material may consist of smooth particles, such as steel shot, or sharp abrasive particles, such as cracked steel grits or clean sharp quartz sand or other materials suit- 5 able for cleaning, hardening, polishing or otherwise modifying the surface characteristics of the articles in the desiredmanner.

What is claimed is:

1. A machine for throwing abrasive comprising 10 a rotor including spaced parallel side members having throwing blades between said side members extending from the periphery of said rotor inwardly short of the axis of rotation thereof to provide a central space, means for feeding abral5 sive throughone of said side members to said space, an impeller carried by a side member at the feed side of said rotor and having vanes in said central space, and a control member having a tubular portion in said space between said vanes 20 and said. blades and formed with an inlet opening at the feed side of said rotor and a discharge opening adjacent the path of rotation of the inner ends of said blades.

2. A machine for throwing abrasive comprising 25 a rotor including spaced, parallel, side members having throwing blades carried between said side members and extending from the periphery of said rotor inwardly short of the axis of rotation thereof to provide a central space, an impeller supported from one of said side members and having vanes in said central space, a spillage opening for abrasive leading from said space through said impeller, a relatively stationary control member having a'tubular portion in said 35 space between said vanes and said blades, said tubular portion having a discharge opening therein adjacent the path of rotation of said blades, and means for feeding abrasive to said' rotor through the side member on which said '40 impeller is mounted.

3. A machine for throwing abrasive comprising in combination, a rotor including a plurality oi throwing blades extending from the, periphery inwardly short of the axis of rotation of the rotor 45 to provide a central space, a relatively stationary control member having a tubular portion disposed in said central space, an impeller having a plu-. rality of vanes rotatable with said throwing blades extending into said tubular portion, a-discharge opening in the wall of said tubular portion, and means extending through said impeller for mounting saidcontrol member in normall stationary position 1 4. A machine forthrowing abrasive comprising 55 in combination, a rotor including a plurality of rotatably mounted throwing blades extending from the periphery inwardlyshort of the axis of rotation of said rotor to provide a central space, means for feeding abrasive into said central space from one side of said rotor, a control member rotatably mounted throwing blades extending 76 I from the periphery inwardly short of the axis 01' rotation oi said rotor to provide a centralspace, means for feeding abrasive into said central space from one side or said'rotor, an impeller having a plurality of vanes in said central space, means 1;

secured to said rotor at the feed side thereof for supporting said impeller for rotation with said blades, a relatively fixed control member having a tubular portion extending into said central space between said vanes and said blades, and means extending through said impeller for supporting said tubular portion.

6. A machine for throwing abrasive comprising a rotor including a plurality of blades extending from the periphery inwardly short of the ams of rotation of the rotor to provide a central space, an impeller rotatable with said blades extending into said space, a control member having a tubular portion in said space between said impeller and said blades and having a mounting portion extending within said impeller, a feed member for feeding abrasive to said impeller, and means ad- Justably supporting the mounting portion on said feed member.

7. A machine for throwing abrasive comprising a rotor including a plurality of'blades extending ijrom the periphery inwardly short of the ams of rotation of the rotor to provide a central space, an

impeller rotatable with said blades extending into said space, a control member having a tubular control portion formed with a discharge opening,

said tubular control portion being disposed in said space between said impeller and said blades, and

a tubular feed portion within said impeller, and a tubular feed member communicating with said tubular feed portionand having substantial continuity of internal surface therewith, whereby abrasive material is delivered through said feed member to the feed portion of said control member without spillage.

8. A machine for throwing abrasive comprising a rotor including a plurality of blades extending from the periphery inwardly short of the axis of rotation of the rotor to provide a central space, an impeller rotatable with said blades extending into said space, a control member having a tubular portion in said. space between said impeller and said blades, and a tubular feed portion extending through said impeller, and a tubular feed member telescoping with said feed portion whereby said feed member and said feed portion provide a closed tube leading from outside said wheel to within said central space.

9. A machine for throwing abrasive comprising a rotor including a plurality of blades extending from the periphery inwardly short of the axis of rotation of the rotor to provide a central space, an impeller rotatable with said blades extending into said space, a control member having a tubular portion in said space between said impeller and said blades, and a support for said control member extending through a central opening in said impeller, a tubular feed spout, and means for adjustably mounting said support on said feed spout.

10. An abrasive projecting machine comprising a rotor'having a plurality of rotatably mounted throwing blades extending from the periphery inwardly short of the axis of rotation of the rotor to provide a central space, means for feeding abrasive into said central space from one side of said rotor, an impeller fixed to rotate with said blades an abrasive spillage opening therein through which stray abrasive may escape.

11. An abrasive projecting machine comprising a rotor having a plurality of rotatably mounted throwing blades extending from the periphery inwardly short of the axis of rotation of the rotor to provide a central space, means for feeding abra- 3 sive to said rotor at one side thereof, an impeller fixed to rotate with said blades extending into said space, a control member having a tubular portion extending into said space between said impeller and said blades, said control member having a discharge outlet in the tubular portion thereof for directing the abrasive into the path of rotation of said blades, said impeller including \a plurality of vanes rotatable in said tubular portion and a mounting portion fixed to said vanes, extending over the edge of said tubular portion adjacent the feed side of said rotor, and fixed to said rotor.

JOHN E. GUENDLING,

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