US2049466A - Abrasive throwing wheel - Google Patents

Description

Aug. 4, 1936. v v. MINICH 2,049,466

ABRASIVE THR OWING 'WHEEL Filed July 5, 1955 2 Sheets-Sheet 1 INVENTOR I emelffimztlb BY a E ATTORNEYZ Aug. 4, 1936. v. E. MINICH ABRASIVE THROWING WH EEL- 2 Sheets-Sheet 2 Filed Jilly 5, 1955 1 INVENTQR Verne Eflmrr/L a 4 ATTORNEY Patented Aug. 4, 1936 UNITED STATES snnssrvs 'rrmowme WHEEL Verne Elwood Minich, Mishawaka, 1nd. Application July 5, 1935, Serial No. 29,869

8 Claims.

This invention relates to an improved abrasive throwing wheel for centrifugally throwing abrasive particles such as sand, steel shot, steel grit and the like at high velocities.

It is one of the purposes of this invention to provide an improved wheel for throwing abrasive at blasting velocities whereby the thrown abrasive may be evenly distributed over the work surface against which the abrasive is directed. In order that the greatest abrading efficiency from the thrown abrasive may be realized, it is important that the thrown abrasive be'not only directed against thework surface, but also that each unit area-of the work surface be impinged uniformly by substantially the same amount of abrasive so that all parts of the work surface will be uniformly and evenly abraded in equal amounts.

In accordance with this invention the wheel preferably comprises spaced side wall members fixed to a rotatable drive shaft. Removable and replaceable throwing blades are radially arranged between the side wall members. The blades extend short of the axis of rotation of the wheel so as to provide a central chamber. An abrasive feed and control mechanism is positioned within the central chamber, this mechanism preferably comprising a rotating impeller fixed to the side wall member to rotate therewith and a normally stationary tubular control member which surrounds the impeller. The impeller operates to throw the abrasive longitudinally of the blades and into the path of rotation thereof. The tubular control member having a discharge opening of limited peripheral length, is adjustably mounted independently of the blades and impeller so that the discharge opening therein can be placed in any clock-dial position. While direction of flight of the thrown abrasive can be controlled by a proper adjustment of the tubular control member and while the length of path of the thrown abrasive is substantially determined by the peripheral length of the discharge opening in the control member, it is desirable to provide means whereby all unit areas comprising the work surface will be impinged by uniform and equal amounts of abrasive.

This I propose to accomplish by providing abrasive throwing blades of varied radial lengths. With a wheel approxhnatelyZilinches in diameter rotating at 2200 R. P. M. a worksurface from 36 to 48 inches in length can be cleaned by the thrown abrasive directionally controlled by the mechanism above described, but the end areas of the work surface are not cleaned to the same extent as the central area. By providing a wheel with blades of varying radial length each unit area of the work surface impinged will receive a major blast from one of the vanes and a minor blast area will overlap a major blast so that the 5 work when completed will be substantially uniformly abraded over all unit areas.

In the preferred form of wheel the blades are '-so arranged with respect to one another that the wheel will be dynamically balanced thereby 1,0 greatly reducing or substantially eliminating vibration. In one form of wheel several pairs of blades are used, each pair of a different radial length. The blades of each. pair are placed diametrically opposite one another so that the com- 15 pleted wheel is substantially dynamically balanced in spite of the fact that the various pairs of blades vary in length and in weight. If desired, however, blades of uniformly increasing lengths may be radially arranged in wheel for- 20 mation so that the ends of the blades describe a. substantially spiral curve. Balancing weights or members maybe used to ofiset the unbalancing effect of the variegated'length blades and maintain the wheel in dynamic balance.

In order thatthis invention may be clearly understood and readily carried into effect, the same will now be more fully described with reference to the accompanying drawings, illustrating by way of example, several embodiments of 30 the invention, and in which:

Fig. 1 is a longitudinal cross sectional view of the preferred form of wheel taken on line l--l of Fig. 2, this figure showing the preferred arrangement of the variegated length blades;

Fig. 2 is a transverse cross sectional view through the assembled wheel taken at the line 2-4 of Fig. 1; I

Fig. 3 is a diagrammatic view illustrating the direction of movement of the abrasive thrown 40 from the wheel equipped with blades of variegated length, as shown in Figs. 1 and 2;

Fig. 4. is a side view of a wheel of somewhat modified form, particularly illustrating a wheel in which the variegated length blades are so 45 arranged that the ends of the blades describe a substantially spiral curve, certain parts being broken away to more clearly illustrate the construction; and I Fig. 5 is a transverse cross sectional view 50 through the wheel shown in Fig. 4, this view being taken on line 5-5 of Fig. 4.

Similar reference characters refer to similar parts throughout the several views of the drawings and specification. M

The wheel may comprise a rear side wall disc I and a front side wall disc 2 joined together in fixed spaced relationship by spacing studs 3 which may be bolted or otherwise secured to the discs I and 2. The front. and rear side wall discs are rotatably mounted on a shaft 5 fixed to the hub 6 secured to the rear side wall disc I by bolts I. Throwing blades extend radially short of the rotating axis so as to provide a central chamber c.

Control mechanism, positioned within the central chamber 0, operates to direct a controlled stream of abrasive longitudinally of the blades and into the path of rotation thereof. The control mechanism preferably comprises a tubular control member I0, which may have an inwardly extending flange I3 at the inner end thereof. The control member ID is mounted independently of the wheel on a suitable support II. A rotating impeller is mounted within the control member and preferably fixed to rotate with the wheel. The impeller comprises a rear side plate I5 and a front side plate I6 connected by a plurality of impeller vanes IT. The impeller may be fixed to the rear side wall disc I by means of a bolt I8 which screws into the centering plate ,I 9 fixed to the rear side wall disc I by means of screws 2I. The abrasive flows from a feed pipe 50 into the impeller through a large control opening 32 in the front side plate I6 thereof. The abrasive drops radially across the impeller vanes I1 and is then whirled within the tubular control member Ill until thrown through the discharge opening 0 therein with considerable force across the inner ends of the blades and into the path of rotation thereof. It will be noted that since the impeller rotates with the blades and substantially at the same speed as the inner ends of the blades, the abrasive moves gently on to the advancing face of the blades without destructive shock to the abrasive or to the blades. The abrasive gains momentum as it moves across the face of the blade and is thrown from the outer end of the blade with great force. Under the same operating conditions, a fixed relationship exists between the clock-dial position and the discharge opening 0 in the control member and the point of discharge from the wheel. By adjusting the position of the discharge opening 0, the direction of flight of the thrown abrasive may be readily controlled. The position of the discharge opening 0 is adjusted by rotating the control member III to bring the opening around to the point desired.

The overall length of the discharge outlet 0 determines the length of path swept by the thrown abrasive. With such an opening, however, and with blades of uniform length, the

discharged from each blade will cover a particular assigned area, and the lesser concentration of discharge from each blade will be distributed uniformly over the whole area. To facilitate description, the wheel, as shown in Figs. 1 and 2, is provided with eight blades, the longest of which is designated be, and the shortest b: and the inter:

mediate length blades b4 and be, respectively.

The proper length of the respective blades for most efficient operation is determined to a considerable extent by the diameter of the wheel 'and 2 and the connecting studs 3 are preferably so shaped, weighted and arranged as to present a substantially dynamically balanced wheel. In order that the variegated lengthblades may not throw the wheel out of dynamic balance, I prefer to provide paired blades of variegated lengths, the blades of each pair being arranged and po sltioned so that they tend to balance one another. Thus, it will be noted byreferring more particularly to Figs. 1 and 3 that the long blades be are arranged diametrically opposite one another and the short blades b: and the intermediate length blades brand be are also arranged diametrically opposite one another. When thus arranged, the wheel is dynamically balanced and can be run at high speed without serious vibration. The blades are preferably channel shaped, comprising a bottom portion I00 and side flange portions III within which the abrasive is confined. The blades if desired may be supported within channel grooves 25 cut in the side wall discs I and 2. The blades are pushed into the paired grooves 25 until the inner ends thereof strike the centering plate I9, thus assuring that the blades are properly positioned within the wheel. The blades may be removably held in operative position by means of screw elements I2 which extend through the side wall discs I and 2 and seat behind suitable lugs I02 projecting from the rear face of the blade. When the blades have been sufiiciently worn by the moving abrasive, they may be replaced by a new set.

The operation of the wheel as above described is more particularly illustrated in Fig. 3. The shortest blades b: will pick up the abrasive at the discharge opening 0 and fling the same in concentrated form approximately over the area oz. The abrasive picked up by the blades b4, slightly longer in length, will .carry the abrasive a little farther along and discharge the same in concentrated form approximately over the area o4. Similarly, the abrasive picked up at the discharge outlet 0 by the blades b6 and ba will be similarly thrown in concentrated form still farther along over the areas as and as respectively. A certain amount of the abrasive will also be scattered by each blade over other portions of the work surface, but the net result of the impingement will give a substantially uniform distribution of the abrasive over the entire area.

There is shown in Figs. 4 and 5 a wheel of somewhat modified form in which blades of variegated length are radially arranged in spaced relationship so that the outer ends thereof describe a spiral. To maintain the wheel in dy namic balance a plurality of weights are positioned between the side wall discs I and 2 to offset the unbalancing eifect of the variegated length blade. Thus, for example, a balancing weight 91 is provided adjacent the short blades b1 and correspondingly varying weights 92, ya. 94, us. as and .01 are provided adiacent the blades be.

b4, b5, b s and respectively so that the wheel when fully assembled is dynamically balanced.v

Each of the blades hi to D7, inclusive, throws the abrasive in concentrated form over a predetermined limited area and the relative lengths of the blades are such as to obtain substantially even distribution of the abrasive over the entire work surface.

It is understood that a .wheel having any desired number of blades may be provided. A wheel having a diameter of approximately 20 inches has been found to produce effective cleaning when provided with from 6 to 10 throwing blades of variegated length. The shortest blade should preferably be considerably'more than half the length of the longest blade so that the resultant effective abrading action is uniform over the entire work area. The machine as thus constructed will effectively clean metal sheets uniformly and evenly and since the abrasive is substantially evenly distributed, there is no loss in efliciency due. to over abrading certain areas and under abrading other areas.

While certain novel features of the invention are disclosed and 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. A rotor for throwing abrasive at blasting velocities including, spaced rotatably mounted abrasive throwing blades, and means for feeding abrasive into the path of rotation of said blades, some of said blades varying in radial length so as to effect. even distribution of the thrown abrasive over the work surface, the inner ends of said blades being spaced approximately equidistant from the axis of rotation of said wheel.

2. A rotor for throwing abrasive at blasting velocities including, abrasive supply means, radially arranged abrasive throwing blades rotatably mounted around said abrasive supply means, said blades being adapted to receive the abrasive discharged into the path of rotation thereof and throw the same centrifugally from the outer end thereof, some of said blades varying in radial length so as to distribute the thrown abrasive uniformly over the work surface, the inner ends of said blades being spaced approximately equidistant from the axis of rotation of said wheel.

3. A rotor for throwing abrasive having radially arranged abrasive throwing blades of dif-' ferent radial lengths, said blades being so arranged that the outer ends of the blades describe circles of different radii.

4. A rotor for throwing abrasive at blasting velocities including, plurality of rotatably mounted throwing blades radially arranged around said supply means.

said blades being of different radial lengths so from all of said that the concentrated discharge blades will sweep a path of uniform intensity across the work surface, said blades being so arranged that the outer ends of the blades describe circles of different radii.

5. A rotor for throwing abrasive at blasting velocities including, abrasive supply means, spaced rotatably mounted abrasive throwing blades'radially arranged around said supply means adapted to receive the abrasive discharged into the path of rotation thereof and throw the same centrifugally, said blades varying uniformly in radial length around the rotor periphery so as to effect even distribution of the thrown abrasive over the work surface, the inner ends of said blades being spaced approximately equidistant from the axis of rotation of said wheel.

6. A rotor for throwing abrasive at blasting velocities including, spaced rotatably mounted abrasive throwing blades, and means for feeding abrasive into the path of rotation of said blades, some of said blades varying in radial length so as to effect even distribution of the thrown abrasive over the work surface, said blades being so arranged with relation to each other that a dynamically balanced wheel is provided, said blades being so arranged that the outer ends of the blades describe circles of different radii.

abrasive supply means, and a 7. A rotor for throwing abrasive at blasting are substantially equal in length and each pairclifiering in length from other pairs, the blades of each pair being arranged diametrically opposite each other so that'a dynamically balanced wheel is provided, the inner ends of said blades being spaced approximately equi-distant from the axis of rotation of said wheel.

8. A rotor for throwing abrasive at blasting velocities including, means for directing a stream of abrasive off center but near the axis of rotation of the rotor, and. radially arranged blades of different length adapted to successively pick up charges of abrasive flowing from said directing means and throw said charges centrifugally at predetermined points over the work surface, said blades being so arranged that ends of the blades describe circles of different radii.

' VERNE ELWOOD MINICH.

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