US2119812A - Abrading apparatus - Google Patents

Description

June 7, 1938. E 0, HAMREN 2,119,812 n ABRADI NG APPARATUS Filed May 14, 1936 Fig .U F4' g. Ji

Patented June 7, 1938 Eric 0. Hamren, Hagerstown, Md., assigner to Pangborn Corporation, Hagerstown, Md., a

' ,corporation \of Maryland Application May 14, 1936, Serial No. 79,788

18 Claims.

This invention relates to abrading apparatus and more particularly to mechanical apparatus for propelling abrasives at abrading velocities.

Abrasive throwing wheels having bladed rotors have been known in the art for many years, and although they are now going into rather wide use they are open to the objection that valuable time is lost changing blades. The blades of abrasive propelling rotors must be made removable,

so that they may be replaced when they have worn out, and yet must be held so securely that they will resist the tremendous centrifugal force exerted when the wheel is operating. In the co-pending application of Walter L. Keefer, Se-

rial No. 79,559, iiled May 13, 1936, there is disclosed a threaded locking assembly, which facilitates blade removal and replacement, and it is the purpose of this invention to provide locking assemblies which are of a somewhat different character and which possess certain advantages over those shown in the Keefer application.

It is a primary object of this invention to provide novel vabrading machine blade locking assemblies that securely hold the blades in place and yet permitthem to be removed and replaced in a minimum of time.

It is a further important object of the invention to provide a novel blade assembly for abrading machines that will hold all oi the blades securely in place while the machine is operating, will permit easy and rapid removal and replacement of the blades when they wear out and which will also permit Vthe bladesto be removed and replaced in the machine in a different relatlonship to present different surfaces to the abrasive when certain of their surfaces have become worn.

A further object is to provide, in an abrading machine having a bladed rotor for propelling the n abrasive, a novel blade mounting assembly which will securelyholdthe blades in place and will not work loose during operation of the machine, involves no threaded or complicated parts to be jammed with abrasive, and which will permit the blades to be quickly and easily removed from the rotor. 4

Further objects of the invention will become apparent as the speciication proceeds in connection with the annexed drawing. and from the appended claims.

In the drawing:

Figure 1 is a side elevational view of an abrasive propelling rotor equipped with the blade u assembly of this invention, with parts thereof broken away in order to more cleany illustrate thestructure involved. Figure 2 is a fragmentalview looking at the wheel of Figure 1 from the right-hand end yoi' ing part of my invention. 15

Figure 6 is a sectional view takenJ on line 6 9 of Figure 5.

Figure '7 is a view similar to Figure 5, but illus,- trates a still further form of blade locking assembly of theinvention. .20

Figure 8 is a sectional view on line 8-l of Figure '7, but illustrates the screw in elevation.

Figures 9, v10, Il and 12 are views siniilaritoy Figure 7, but illustrate somewhat different forms V of the invention. 25 With continued reference to the drawing, wherein like reference characters have been employed to designate likeparts throughout the several views thereof, the rotor is .designated as R, and it is rigidly secured to a shaft il). Shaft-,30

rotor to define a central abrasive admitting space 35 in which an abrasive feeding device F is rotat ably or stationarily supported, depending upon the type of discharge desired.

The feed device illustrated is substantially thev same as that shown in the copending applica- 40 tion of William A. Rosenberger and Walter L. Keefer, Serial No. 726,188, and it effects direc. tional discharge of the abrasive thrown from the wheel, but it is yto be understood that the v invention is not limited to a particular feeding device but may be applied to any type of 'abrading machine. For instance, feeding devicev F may assume the form of apipe or a chute for dumping the abrasive into the central space and effecting a three hundred and sixty degrees dlscharge of the abrasive. Also, blades B have been shown as four in number, but it is to be understo'od that theinventionl is applicable to rotors-` having more or less than four blades.

, Secured to the face of rotor R, by a plurality e5 of countersunk screws I I, arefour symmetrically arranged plates I2. The radial edges of plates I2 are provided with bevelled faces I3, and the adjacent edges of each pair of plates define a dove-tail groove I4, as seen in Figure 3.

Blades B are provided with correspondingly dove-tail shaped bases to fit in grooves I4, and have inclined faces I5 cooperating with walls I3 of plates I2. The inclined faces `I5 of blades B merge into abrasive propelling surfaces I6 provided on eacnl side of the blade. As seen in Figure 1, inclined faces I5 merge with plates I2 in a region spaced from their propelling surfaces IB, with the result that the abrasive moving outwardly over surfaces I6 is maintained out of abrading contact with plates I2, which are permanent parts of the machine. 'I'lie free edges of blades B are each provided with a flange or ridge |'I to confine the outwardly moving abrasive to surfaces I6.

The blades are accordingly mounted for gulded movement toward and away from the axis of the rotor, and although grooves I4, which constitute the guideways, are shown as being disposed substantially radially, it is to be understood that they may be inclined forwardly or rearwardly with respect to the direction of rotation if desired without departing from the spirit of the invention. b

'I'he preferred form of locking assembly employed for restraining blades B against outward movement is shown in Figures 1, 2, 3 and 4, and with continued reference to these figures, the outer end of each plate I2 is provided with a recess |3 and a wall I9 disposed parallel to the axis of rotation of the rotor. As seen in Figure 2, recesses I8 and walls I9 cooperate to provide a generally T-shaped recess. Fitting in each recess is a T-shaped locking member or "key 2|, against which the blades are adapted to .abut as shown in Figure 2.

Although the friction set up between the parts as the result of the blades tending to move outwardly in response to centrifugal force, I preferably employ, as a safety feature, a positive lock for the key members 2|. As seen in Figure 4, each blade B is preferably provided with a recess defining a shoulder 22 which is adapted to embrace the outer side of the key when it is disposed in locking position. Blades B are removed from the rotor by tapping them lightly with a hammer so as to move' them inwardly sumciently far to allow keys 2| to be slid past shoulder 22. In order to facilitate removal of the keys when the blades have been moved inwardly as just described each key is provided with a recess 23 in which a screw driver or other tool may be inserted to pry the keys loose. 'I'he inner end of each blade B is also provided with a recess defining a shoulder 22 so as to permit the blades to be removed and reversed.

It is accordingly seen that I have provided a simple effective locking means for the blade, not involving any screw-threaded or other closely iltting parts and yet which may be readily removed to permit blade removal and replacement.

When a new blade is slid inwardly in groove I4, it is slid slightly past the position shown in Figure 4, so that keys 2| may be easily slid into place to bridge the open end of the slot. After this has been effected, blades B may be slid out wardly to lock keys 2| in position, but if desired the wheel may be merely started as centrifugal force will move the blades out into cooperating engagement with the keys as soon as the rotor is started. The inherent friction present between blades B and their guides may be relied upon to restrain them against inward movement when the rotor is subsequently stopped, but if desired spring means, taking the form of a spilt resilient ring, encircling feed device F and engaging the inner ends of the blades, may be used.

With the wheel rotating in the direction indicated in Figure 2, the abrasive is picked up by and discharged from the counter-clockwise surfaces IB of blades B. By reason of the symmetrical design of blades B it is possible to remove the blades when they have become partially worn and reverse them end-for-end and thereby bring a new propelling surface into cooperation with the abrasive. The worn surface is accordingly placed on the clockwise side of cach blade. When the new surface has become worn the blades are of course discarded.

In Figure 5 there is shown a somewhat modifledform of locking assembly and it assumes the form of a locking member 3| extending through an opening 32 in rotor R, the latter preferably having ears provided thereon adjacent opening 32 in order that the general diameter of the rotor may be maintained. Locking member 3| is of generally cylindrical form and is provided with a head 33 and an unthreaded shank.

As seen in Figure 6, head 33 is square and one of its flat sides preferably engages blade B behind shoulder 22. As pointed out in connectionV with the first form of the invention', non-shouldered blades may be used. Plates I2a are preferably cut away to provide recesses 35, which afford working spaces adjacent heads 33 of member 3|. Member 3| may be provided with a round head if desired, but it is preferably of square or hex shape as this type of member may be secured at low cost.

It is apparent that by moving blades B slightly inwardly from the position shown in Figure 5, member 3| may be readily removed from the machine and the blades removed from rotor R by sliding them out of guideways I4. The assembly operation is performed in the reverse order. It is apparent that as members 3| are unthreaded they cannot be affected by straying abrasive and if they should stick they may be pushed out either by a punch applied to the left hand end of the bolt or by prying under head 33 with a screw driver or the like.

In view of the fact square or hex head bolts may be purchased at low cost I may if desired employ them instead of the unthreaded members shown. In such event holes 32 would of course be made of larger diameter than the threaded portion in order that the screws may freely slide therein.

In Figures '7 and 8, I have illustrated a further modification of the invention wherein rotor R is provided with a bore 4I provided with a communicating keyway-like passage 42. A counterbore 43 is also formed in rotor R adjacent bore 4I. A locking member 44 is disposed in bore 4I and is provided with a radially extending spline or tooth 45 and a square head 43.

As seen in Figure 7, member 44 is restrained against movement to the left by engagement of tooth 45 with the bottom of counterbore 43 and it is restrained against movement toward the right by engagement with blades B. It is apparent that by reason of the shoulder formed on members by heads 46 it is unnecessary to employ a shoulder 22 on blade B.

When it is desired to remove blade B, the latter is pushed inwardly a slight distance, member 44 is rotated through 180 degrees oruntil tooth 45 is aligned with passageway 42, by grasping head 46 with a suitable tool. Member 44 may then be slid to the left as tooth 45 will slide within passageway 42.. The locking member may then be completely removed from the device if desired, but it is of course only necessary to move it a distance approximately equal to the height of head 46 in order to remove the blade from the machine. When the parts are disposed in the locked position illustrated in Figure 1, it is apparent that the engagement of blades B and one of the flat sides of head 45 positively restrains member 44 against angular movement about its axis and therefore prevents the latter from working into its unlocking position.

In the form of invention shown in Figure 9, a

2o plug-like member 5| is preferably pipe-threaded into rotor R and is provided with an internal hexagon-walled socket 52 so that it may be operated by a suitable hex wrench. Member 5| is provided with a' head having a tapered wall 53 and the outer edge of blade B is preferably provided with a similarly tapered surface 54. When the parts are disposed in the position shown in Figure 9, it is apparent that engagement of tapered surface 54 with tapered surface 53 of the plug head prevents the plug head from working into its released position. Although member 5| is threaded the thread is of the pipe variety and hence is self-cleansing.

When it is desiredto remove the blade it may be driven inwardly to permit plug 5| to be unscrewed, but if desired socket may need only be engaged by a wrench, and the plug unscrewed because during this operation tapered surface 53 of the plug will, in moving to the left, tend to push or cam blade B into slightly inward position and permit the plug to move into released position.

If desired, plug 5| may assume the form of a cylindrical unthreaded member and be provided with a stop for preventing it from moving to the right in response to the centrifugally induced forces applied to tapered surface 53 by blades B.

In Figure 10, I have illustrated a locking assembly of this character. Plug 5Ia is provided with a shoulder portion 56V seating in a counterbore 58 in rotor R. It is therefore apparent that the tendency of blade B, to push plug 5|a to the right, in response to application of forces to tapered surface 53a, will merely pull shoulder portion 56 into engagement with the bottom of counterbore 58.

In Figures 11 and 12, I have illustrated blade locking assemblies which are held in place by a set screw.

In Figure 11 a locking member 6|, having a circumferential groove 62, is slidably mounted in a bore 63 in rotor R. Member 6| is provided with a reduced portion 65 which provides an abutment for blades B. A block of rubber 66 is mounted in a bore 61 and is adapted to be forced into groove (i2-the blade locking position-shown in Figure 1l by a set screw 68, which preferably is provided with pipe threads, so that it will undergo a self-locking action when it is turned home. It is apparent that set screw 68, when unscrewed, will relieve the block 61 and will permit member 6| to be removed, thereby permitting blade removal and replacement.

In Figure 12, a somewhat similar structure is internal pressure in rubber shown but bore 63 is larger and a'rubber bushing 63 is disposed between it and member 6Ia.

Set screw 68a is provided withl a plunger portion 1|, which as seen in Figure 12, will deform bushmay be duplicated on each disc.

The term guideway, as employed in the appended claims, is used in its broader sense and is intended to cover a partial or incomplete guideway. For instance the guideway provided by plates |2 might be discontinuous, that is, short guiding portions may be provided adjacent their inner and cuter end s and yet the blades would still be mounted for a small degree of sliding movement. t

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to b'e 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: v

1. For use in an abrading machine, a rotor having at least one outwardly extending guideway provided thereon, an abrasive propelling blade mounted for sliding movement in said guideway,

and locking means for restraining said bladek against outward movement in response to centrifugal force developed therein through rotation of said rotor, said means comprising a member mounted for sliding guided movement in a direction substantially normal to said guideway and being releasable to permit said blade to be removed from said guideway, said lblade having a surface cooperating withsaid locking means and operable to maintain'the latter in locking relationship when said rotor is in operation.

2. For use in an abrading machine, a rotor abutment face and restrain said blade against removal outwardly from said guideway when it is disposed in a locking position and to allow said blade to be removed outwardly when it is disposed in a release position, said means being mounted for guided sliding movement in a direction substantially normal to said guideway, said blade being operable to maintain said means `in blade locking position when said rotor is in'operation.

3. The rotor construction dened in claim 2, wherein the abutment face of said blade is operable to maintain said means in blade-locking position when said rotor is in operation.

4. The rotor construction described in claim 2, wherein said guideways comprise a pair of outwardly extending surfaces between which said blade is disposed, and wherein said means is carried by said rotor and disposed between said surfaces.

5. For use in an abrading machine, a rotor hav- Il il ing at least one outwardly extending guide means provided thereon, an abrasive propelling ,blade mounted in said guide means., an elongated member extending through said rotor and having a locking portion, said member being freely slidable in a direction substantially normal to said gui'de means and being movable to bring its locking portion into the path of a surface of said blade wl en said member is rotated about its axis, said locking portion of said member being so shaped that when said blade surface is engaged therewith said member cannot be rotated about its axis and is thereby maintained in locking position.

6. For use in an abrading machine, a rotor having at least one outwardly extending guidewayprovided thereon, an abrasive propelling blade mounted for sliding movement in said guideway, said blade having at least one outwardly facing abutment wall provided thereon, a locking member mounted for freely sliding movement in one direction in said rotor in a direction substantially normal to said guideway and movable into the path of movement of said blade for restraining the same against outward movement in response to centrifugal force, said locking member having a portion adapted for interlocking engagement with said abutment wall of said blade, whereby said blade is operable to restrain said locking memberl against turning movement when said rotor is in operation, means provided on said blade for preventing said locking member from moving in one direction out of the path of said blade, and means provided on said member for preventing it from moving in the other direction out of the path of said blade.

'7. The rotor construction described in claim 6, wherein the said portion of said locking member is provided with at least one flat side which cooperates with the abutment wall of said blade.

8. In an abrading apparatus, a rotor having an outwardly extending guideway provided thereon, an abrasive propelling blade mounted for sliding movement in said guideway, means for restraining said blade against outward movement in said guideway comprising a key member bridging the outer end of said guideway and providing p an abutment wall against which the outer end of said blade is adapted to abut, means for restraining said key member against outward movement, and means for preventing said key member from moving out of locking cooperation with said blade when said member is engaged with saidA blade.

9. The abrading apparatus described in claim 8, wherein said key member is mounted for guided sliding movement in a direction normal to said guideway, and said last-named means is operable to restrain said key member against sliding movement.

10. The abrading apparatus described in'claim 8, wherein said last-named means comprises a shoulder provided on said blade which is operable to engage said key member.

11. In an abrading apparatus, a rotor having an outwardly extending guideway provided thereon, an abrasive propelling blade mounted for sliding movement in said guideway, said rotor also having a pair of inwardly facing abutment walls provided thereon adjacent the outer end of said guideway, said walls being on opposite sides of said guideway, and a key member bridging the open end of said guideway and bearing against each of said abutment walls, said key member providing an inwardly facing abutment wall against which said blade is adapted to bear, and means for maintaining said key member in cooperating relationshin to said abutmentwalls and said blade.

12. The abrading apparatus described in claim 11, wherein said means comprises a pair of abutment faces provided on said rotor and cooperating with opposite ends of said key member.

1 3. 'Ihe abrading apparatus described in claim 11,'- wherein said means comprises an abutment face provided on said blade which is operable to engage said key member.

14. In an abrading apparatus, a rotor having a blade mounted for inwardand outward sliding movement thereon, said rotor having a pair of open-sided recesses therein, one located each side of said blade, said recesses each providing an abutment wall facing toward the center of rotation of said rotor and an abutment face facing substantially normal to said abutment wall, a key member extending across the outer end of said blade and having portions disposed in said recesses and cooperating with said abutment walls and faces, and means for maintaining said key member in said recesses.

l5. The abrading apparatus described in claim 14, wherein said means comprises a shoulder provided on said blade and which is operable to engage behind said key member when said blade is disposed in its outermost position.

16. In an abrading apparatus, a rotor of disclike form mounted for rotation and having a blade mounted for inward and outwardly sliding movement on one face thereof, said rotor having a bore therein disposed in the path of movement of said blade, a bolt member slidably disposed in said bore and operable to restrain said blade against outward movement, means provided on said bolt member for preventing movement of said bolt away from said one face of rotor when said bolt member is disposed in a predetermined angular position in said bore, and means, provided on one end of said bolt vmember and cooperating with said blade, for preventing said V bolt from moving out of said angular position.

17. The abrading apparatus described in claim 16, wherein said bolt member is provided with a shoulder for abutting said blade and restraining said bolt member against movement toward said one face.'

18. In an abrading machine, a rotor mounted for rotation at high speed and having means providing at least one outwardly extending guideway thereon, an abrasive propelling blade mounted for sliding movement in said guideway and having an outwardly facing abutment wall, said rotor having an opening therein which extends in a direction substantially parallel to the axis of rotation of said rotor and substantially no'rmal to said guideway, a locking member having a shank portion mounted for freely sliding movement in said opening, said member having a head adapted to abut said rotor and adapted to be engaged by the abutment wall of said blade, for restraining the latter against outward movement in response to centrifugal force.

ERIC O. HAMREN.

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