US2024481A - Sand mixer - Google Patents

Description

H. s. SIMPSON Dec. 17, 1935.

SAND MIXER l0 Sheets-Sheet 1 Filed Aug. 18, 1.932

INVENTOR HERBERT 5'. SIMPSON. BY

ATTORNEY 5 La o E 17, 1935. i H. s. SIMPSON 2,024,481

SAND MIXER Filed Aug. 18, 1952 10 Sheets-Sheet 2 INVENTOR HERBERT .s. .S'IMFSOM ATTORNEY Dec. 17, 1935.

H. s. SIMPSON SAND MIXER Filed Aug. 18, 1932 I0 Sheets-Sheet 5 INVENTOR HERBERT 3. SIMPSON.

ATTORN EY UOODOOO .De.17, 1935. H. s. SIMPSON 2,024,481

SAND MI XER Filed Aug. 18, 1932 10 Sheets-:Sheet 4 ATTORNEYS H. S. SIMPSON Dec; 17, 1935.

SAND MIXER l0 Sheets-Sheet 5 Filed Aug. 18, 1932 ATTORN EY Dec. 17,1935. H 5 SIMPSQN v I 2,024,481

SAND MIXER Filed Aug. 18, 1932 10 Sheets-Sheet e -INVENTOR HR8ERT S. SIMPSON.

V ATTORNEY H. S. SIMPSON SAND MIXER Dec. 17, 1935.

Filed Aug. 18, 1932 10 Sheets-Sheet 7' INVENTOR HER5RT s. SIMPSOM ATTORNEY Dec. 17,' 1935. H. s. SIMPSON 2,024,481

I SAND MIXER Filed Aug. 18,1952 10 Sheets-Sheet 8 INVENTOR HERBf/PT 8. SIMPSON.

ABY

ATTORNEY Dec. 17, 1935. H. s. SIMPSON 2,024,481

SAND MIXER Filed Aug. 18, 1952 10 Sheets-Sheet 9 LA LA INVENTOR HIFBRT S. S/MPSO/V.

ATTORNEY H. s[ SIMPSON Dec. 17, 1935.

SAND MIXER Filed Aug. 18, 1932 10 Sheets-Sheet l0 lNV ENTOR HERBERT 5. S/MPSO/V.

BY A

ATTOR N EY Patented Dec. 17, 1935 ATENT OFFICE SAND MIXER Herbert S. Simpsom'Chicago, 111., assignor to The Standard Sand and Machine a corporation of Ohio 00., Chicago, 111.,

ApplicationAugust is, 1932, Serial No. 629,270-

5 Claims.

This invention relates to improvements in sand mixers, and has for its object to provide a sand mixer for conditioning used foundry sand as well as for providing new sand mixtures for molding purposes in foundries.

It is an object of this invention to provide a sand mixer in which the feed hopper isloc'ated on or beneath the surface of the ground, means for elevating the sand to a screen from which the sand is discharged into a mixer, and means in the mixer for properly tempering and thoroughly mixing the sand by causing alternating movements of the sand material from end to end of the mixing trough, together with a smearing action on the material that thoroughly infuses the elements of the mixture.

It is also an object of this invention to provide, in connection with a sand mixer, paddles which have on the ends thereof adjustable and removable hard iron tips made of a special mixture to resist wear.

It is another object of this invention to provide, in connection with a mixer, means for applying a definite amount of water to the sand within the mixer, either continuously to a continuously supplied amount of sand, or a definite amount of water to a definite batch of sand.

which the sand is stored, and operating upon the sand until it is conditioned for use.

It is an object of my invention to provide apparatus of different level so that the point of a discharge into the system is below and adjacent to the point of discharge from the system in order to economize in the delivery and removal of material to be treated and material that has been treated.

It is a further object to provide power means so' interconnected to various elements of the system as to synchronize their movements so as to thereby regulate and accommodate the size of the parts and the speed of the parts to the flow of material therethrough in order to maintain the proper proportioning and treating of the material.

These and other advantages will appear from the following description taken in connection. with the drawings.

Referring to the drawings:

Figure 1 is a side elevation of an inclined type of loading apparatus. The lower part of the 5v apparatus is broken off and slightly displaced from the other part thereof.

Figure 2 is a front elevation of the loading apparatus shown in Figure 1.

Figure 3 is a side elevation of a slightly modified form of feeding apparatus in which there is a vertical type of feed.

Figure 4. is a side elevation of the apparatus shown in Figure 3.

Figure 5 is an end view of one form of screening and mixing apparatus, showing the parallel drive. V

Figure 6 is the other end of the apparatus shown in Figure 5.

Figure? is a side elevation'of the apparatus shown in Figures 5 and 6.

V Figure 8 is a side elevation of the mixer with the screen removed, showing the motor, the gear reduction casing and the parallel drive.

Figure 9 is a view from the lefthand end of Figure 8.

Figure 10 is a View of the righthand end of Figure 8. 2

Figure 11 is a view showing the motor and the shaft. operated by the motor extending at right angles to the motor shaft for operating the mixer.

Figure 12 is a view showing the righthand side of the apparatus shown in Figure 11. This-figure shows'the reduction gear case forming a connection between the motor shaft and the shaft extending at right angles thereto.

Figure 13 is a side elevation of the mixer with the screen removed, showing a modified form of mixer drive.

Figure 14 is a view showing the lefthand end of the apparatus shown in Figure 13.

V Figure 15 is a view'showing another modified form of drive for the mixer.

Figure 16 is a view showing one form of paddle and the shaft upon which they are mounted.

'Figure 17 is a view showing the stirrer shaft having-a plurality of paddles thereon, arranged in groups, a stirrer between adjacent groups and a scraper associated with each group and supported by the shaft. In this figure the paddles are shown equipped with removable tips.

Figure 18 is a view similar to Figure'l'l, but

showing the paddles without removable tips.

in Figure 17 and the trough in which the paddles rotate.

In the form shown in Figures 1 and 2 there is a base I, upon which a frame structure 2 is mounted for supporting the operating parts. Connected to some source of power, such as a motor shaft, is a drive pinion 3, shown in Figure 2, which meshes with a gear 4 located on one end of a shaft 5 suitably supported by the frame in bearings.

On this shaft 5 is a pinion 5 which meshes with a large gear I located on a shaft So, on which there is also located a sprocket wheel 8. On this shaft 8a are clutch members 9, by which the sprocket wheel may rotate with the shaft 8a, or independently thereof. Engaging the sprocket wheel is a sprocket chain I0, which extends upwardly therefrom and passes over a second sprocket wheel I I located on a shaft l2 supported in bearings I2a on top of the frame.

The sprocket wheel H is located adjacent one of the bearings -i211. About the middle point of the shaft [2 is a sprocket wheel [3 which carries a sprocket chain 14 on which are buckets I5. This sprocket chain extends downwardly in an inclined direction, and engages a second sprocket wheel [5 located on a shaft II. This shaft is supported at its ends by means of take-up bearings l8 suitably supported in a housing [9 located in a pit or bin 20, from which the sand is to be loaded.

Located in one side of the bin or pit is a feed hopper 2 I, the upper surface of which is substantially level with the ground or floor of the building in which the apparatus is located. Extending through the bottom of this hopper is a worm shaft 22 supported at each end by a bearing 23. The worm part of the shaft is indicated by the numeral 24 and is used for removing the sand from the hopper to the housing l9, where it is received by the buckets l5 and conveyed upwardly in an inclined direction. 7

This shaft 22 is operated by means of a sprocket wheel 25, a sprocket chain 25 and a sprocket wheel 21 located on shaft II. By means of the foregoing structure power is transmitted from the pinion 3 to the gear 4, to the shaft 8a, shaft [2, sprocket chain M to the shaft I1, and from shaft I! to shaft 22 and the worm thereon.

The mixer as shown in Figure 2 is indicated by the numeral 28 and is supported by a frame structure 29 mounted upon the base I. The shaft Ba extends through the mixer and has on one end a sprocket wheel 30, which is engaged by a chain 3| that passes over another sprocket wheel 32 located on one end of a short shaft 33 supported by a standard 34, which is suitably supported by the frame structure 29.

To the other end of the shaft 33 is attached one end of a screen roller 35. The other end of this roller is supported for rotation by means of rollers 35. Beneath the mixer is a discharge door 31 supported beneath the mixer so it will swing to one side for opening a discharge outlet.

The sand as it is conveyed upwardly by means of the buckets I5 is dumped into a hopper 38, from which it is discharged through a chute 39 into one end of the screen roller 35. This end of the screen roller is open to receive the discharge end of the chute 39, and is indicated by the numeral, as shown in Figure 1.

In the form shown in Figure 3 the bin or pit is indicated by the numeral 4|, which has a shallow part 42 in which is located a hopper 43. Located on the floor of the shallow part of the bin or pit is a frame 43a, which supports a pair of shafts 44, one at each end of the frame. On each of these shafts is a pair of sprocket wheels 45, carrying sprocket chains 45 for operating and supporting a belt or steel apron 41 for feeding the sand from the hopper 43 into a housing 51 located in the deep part of the bin.

There is also located on one of the shafts 44 another sprocket wheel 48, over which a sprocket chain 49 passes and engages a sprocket wheel 50 located in one end of a transverse shaft 5| located between the twoshafts 44. On the other end of this shaft 5| is a sprocket wheel 52 engaged by a sprocket chain 53, which passes over another sprocket wheel 54 located on one end of the shaft 55 supported by take-up bearings 56 in the housing 51, which receives the sand from the hopper.

Intermediate the ends of the shaft 55 and within the housing 51 is a sprocket wheel 58 engaged by a sprocket chain 59, which passes upwardly and over a sprocket wheel 60 located on a shaft M on top of the frame 62. The sprocket chain 59 carries a plurality of sand hoisting buckets G3. Located near the top of the frame 62 and to one side thereof is a platform 64, which has downwardly extending supporting brackets 55.

On this platform is a reducing gear box 66 which has extending therefrom a shaft 61 connected by means of a connection 58 to the shaft 6!. The platform 64 also supports a motor 69, as shown in Figure 3. This motor has a shaft 18, which by suitable connection extends into the reducing gear box and transmits motion to the shafts 61 and GI.

The sand conveyed upwardly by means of the buckets is dumped into a chute H, from which the sand is discharged into a hopper 12 located at one end of the revolving screen 13. This screen operates in all particulars as the screen described in connection with Figures I and 2, and is supported at one end by means of rollers 14 and at the other end by means of a shaft 15 supported on a bracket 16.

Shaft 1'5, by means of a sprocket chain construction H, drives a shaft 18 which is supported by bearings 88. The driving mechanism between the shaft 15 and the shaft 18 is inclosed in a casing 19. Shaft 18 extends through the mixer 8| and has thereon paddles for stirring and thoroughly mixing the sand. The shaft 18 is connected to another shaft 82 by means of a coupling 83. This shaft 82 extends into a gear reducing box 84 connected to a motor 85 by means of a motor shaft and connection 85. The motor and reducing gear box are supported on a platform 81 supported by supports 89 and braces 88.

For the purpose of supplying water to the mixer a pipe 98 is provided, which has a valve 91 for regulating the fiow of water through the pipe into the mixer. Located in the bottom of the trough of the mixer is a discharge gate 92, operated by a rack 93 engaged by suitable teeth on a shaft 94, which has a sprocket wheel 95 engaged by'a chain 93 and operated by a sprocket wheel 91 located on a shaft 98 by means of a hand wheel 99. g

In theform shown in Figures 3 and 4 the apron for conveying the sand to the buckets and the buckets are operated by one motor, while the screen and the mixer are operated by a second 7 0 motor. These parts operate independently but may be regulated so that action of one part is somewhat synchronized with the action of the other parts. I

In the form shown in Figures 5, 6 and 7 the loading mechanism isomitted and the mixing apparatus is shown, for batch mixing purposes; that is, to a definite amount of sand a definite amount of water is applied. In this form the supports for supporting the superstructure are indicated by the numeral I00, which has located thereon a platform I III for supporting a motor I02, which has a motor shaft I03 in connection, extending into a reduction gear box I04, also supported by the platform.

Extending from the reduction gear box is a shaft I 65, which is connected by means of a coupling I86 to a shaft ID'I supported by suitable bearings I08 and extending through the mixer 19..

The mixer in all the various forms may be provided, on each side, with a clean-out door IllSa, which is readily removable for cleaning out the mixing trough and thereby preventing the building up of the material in the bottom and sides of the trough. By means of this removable door it is unnecessary to disturb the screen at any time for cleaning purposes. These doors are rectangular in shape and have on each side an angle iron I691) by which the doors are suitably attached to the other parts of the mixer by bolts I090.

On the shaft M1 is a sprocket wheel IIO operating a sprocket chain III which passes upwardly and over a sprocket wheel H2 located on shaft IE3 supported by a suitable bearing H4. The sprocket wheel I I2 is on one end of the shaft IE3, which has on its other end, one end of a rotating screen I I6 which has in its other end an inlet I I I and is supported by rollers I I8 mounted upon the frame H9, suitably attached to one end of the mixer. For the purpose of protecting the sprocket chain I I l and the sprockets engaged thereby there is provided a casing I I5.

For supplying a definite amount of water to a definite batch of sand there is provided at one side of the mixer a water tank I20, which is connected to the mixer by means of a pipe I-2I. On each side of the mixer is a guard I22, which extends part of the way upwardly oneach side of the rotating screen. In this form of apparatus a discharge door I23 is located in the bottom 'of the trough of the mixer, and is operated by means .of a rack I24 engaged by a pinion I25 on a shaft I26, which is operated by a hand-wheel I27.

In Figures 8 to 12 a mixer is shown with various connections between the motor and the mixer. In Figures 8, 9 and 10 the parts are in alignment with each other. In this form there is provided a base I28 for supporting the various parts of the apparatus. A motor I 29 is supported on one part of the base and is connected by means of a shaft and coupling I30 to a reduction gear box I3 I. Extending from this box is. a shaft I32 parallel with the motor shaft and connected by means of a coupling I33 with the shaft I34 supported in suitable bearings I35.

The mixer through which the shaft extends is indicated by the numeralI36 and has at one end a discharge opening 13%., and is supplied by a pipe I37 with water for properly moistening the sand being treated. In this type of mixer the sand is continuously fed, and a continuous supply of water is supplied to the sand. In this respect this form of apparatus differs from that shown in Figures 5, 6 and 7.

In the form shown in Figures 11 and 12 the motor shaft is at right angles to the mixer shaft. The motor I29a is supported on a base I28a and is connected by'means of a motor shaft and connection. I3Ila toa reduction gear box I am, which has extending therefrom a shaft I 32a connected by a connection I 33a. to the mixer shaft I 34a supported by bearings Ia. The mixer in this form is indicated by the nu- 5 meral I36a.

In Figure 13 there is shown a modified form of drive for the mixer. In this form there is a plurality of bases or supports I38 for supporting the operating mechanism. Two of these supports 10 support a shaft I39, which has thereon a gear I 40 connected to some source of power, and which has on one end a pinion I M meshing with a gear I42 on a shaft I43. This shaft I43 is supported or bearings I44, and extends through a 15 mixer I45. The pinion MI and the gear I42 are protected by means of a casing I46. This mixer is of the batch type and has a tank I45a for discharging a definite quantity of water into the mixer.

In the form shown in Figure 15 the shaft I41 for operating a mixer, through any suitable form of gearing, has thereon a fixed pulley I48, and adjacent the fixed pulley a loose pulley I49.

The paddles are located on the shafts disposed 25 longitudinally through the stirrer trough, such as shaft 80., found in Figures 1 and 2, and shaft 18 of Figures 3 and 4. Each stirrer shaft has thereon a plurality of paddles, each consisting of a stem part I and a blade part I5I, disposed 30- at an angle to the axis of the shaft upon which the paddles are located. The paddles are fastened in pairs to the shaft by means of bolts I 52.

In the form shown in Figure 16 the paddles are arranged in contact with one another so 35- that a small amount of space is between adjacent paddles. In the form shown in Figures 1'7, 18 and 19 the paddles are spaced from one another on the shaft. Extending from the stems of certain of these paddles are arms I53, which 40 v creasing in length from the shaft toward the outer periphery of the stirrer as a whole.

The operation of the blades tends to move the batch of material, sand or whatever it may be, in

The steel blades closely fitting one direction. the inner wall of the trough, tend to keep the material toward the center of the stirrer in the vicinity of the shaft. When the material reaches the agitator its movement longitudinally of the shaft is somewhat broken up, so there is at this point a more thorough agitation and mixing of the sand and the water therein. The tips on the ends of the blades are composed of a special ly formed material that resists wear, and when worn may be easily removed for the application of new tips.

It will be noted that in the mixer the paddles are assembled on the shaft in pairs, one being slightly smaller and shorter than the other and with a reversed pitch. This arrangement causes the material to be moved in a forward direction by the large blade, while the shorter blade, with the reversed pitch, will cause the material to move backwardly in the mixing trough, thereby effecting an alternating motion of the material from end to end of the mixer, as the material progressively proceeds to the discharge. The fact that the larger blade throws more sand forward than the smaller blade can throw backwardly causes the material to progress to the discharge. This results in the discharge of the material from a stationary trough through the door.

The material is supplied to the door for discharge without jamming or binding due to the relatively small amount of material that is delivered despite the sizes of the paddles, which, if operating all in the same direction, would force all the material towards one end of the trough and jam it so that it would not discharge through the door. This alternating motion of the sand from end to end in the mixing trough together with a smearing action on the material thoroughly infuses the elements of the mix in a very short time so as to secure a rapid and adequate blending of sand mixtures. As the sand is moved in both directions it does not matter whether the discharge is at the middle of the mixing trough as in the case of the batch mixer, or at the end of the mixing trough, as in the case of the continuous mixer. Either discharge is direct into containers or onto conveyors without the necessity of spillage and consequent necessity of rehandling the material.

It will be noted that the clean-out door 31 is in the side of the mixer shell M5. This prevents the building up of the material on the bottom and sides of the trough which would tremendously increase the wear on the paddles and the load on the gearing and motor. This makes it unnecessary to disturb the screen at any time, which is arranged to operate close to the top of the mixer with a minimum of head room and an economy of operating parts.

It will be understood that the problem is to handle effectively very large volumes of sand with low labor costs. Also, the mixerincluding a feed hopper and apron, elevates-screen and mixer utilizes the minimum of floor space. Also, one man can easily operate the largest capacity unit. It is important to screen the sand thoroughly and it is equally important to uniformly and accurately aerate the sand.

It will be understood that it is desired to comprehend within this invention such modifications as come within the scope of the claims and the invention.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. In a-mixer, a trough a shaft having thereon a plurality of paddles arranged in groups for rota.-

tion in the trough, and a pair of oppositely disposed stirrers on the shaft between the paddles of one group and the paddles of another group, each stirrer having on opposite sides projections extending in a direction substantially parallel to 5 the shaft, the projections increasing in length from the shaft to the outer end thereof.

2. In combination, a mixing trough, a shaft extending therethrough having a plurality of paddles assembled on said shaft inpairs, one of said 10 paddles being slightly smaller and shorter than the other and with a reverse pitch, one of said paddles being arranged to give a higher materialmoving rate than the other, whereby different portions of the material move oppositely at dif- 15 ferent rates but with a resultant preponderating movement as a whole in one direction.

3. In combination, a mixing trough, a shaft extending therethrough having a plurality of paddles assembled on said shaft in pairs, one of said 20 paddles being slightly smaller and shorter than the other and with a reverse pitch, one of said paddles being arranged to give a higher materialmoving rate than the other, whereby different portions of the material move oppositely at dif- 5 ferent rates but with a resultant preponderating movement as a whole in one direction, and a discharge means on the side of said trough.

4. In a mixer, the combination of means for spraying the material as it is fed through said 30 mixer, and means for feeding the material to the discharge thereof consisting of a shaft, a plurality of stirrers mounted on said shaft, each stirrer beingprovided with a plurality of paddles all located in a plane transverse to the axis of said 35 shaft, alternate paddles forming each stirrer being longer and oppositely faced than the other paddles, one set of paddles being arranged to give a higher material-moving rate than the other set whereby different portions of the material move 40 oppositely at different rates but with a resultant .preponderating movement as a whole in one direction.

5. In a mixer, the combination of means for feeding the material to the discharge thereof con- 45 sisting of a shaft, and a plurality of stirrers mounted on said shaft, each stirrer being provided with a plurality of paddles all located in a plane transverse to the axis of said shaft, alternate paddles forming each stirrer being longer and oppositelyfaced than the other paddles, one

set of paddles being arranged to give a higher material-moving rate than the other set whereby different portions of the material move oppositely at different rates but with a resultant preponder- I6 ating movement as a whole in one direction.

HERBERT S. SIMPSON.

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