US1520916A - Sand cutting and screening machine - Google Patents

Description

J. S. TOWNSEND SA D CUTTING AND SCREENING MACHINE Fil d De 1921 3 Sheets-Sheet 1 ,Ea N J0%flz '5'. 1 00726571625.

/ I I v 3Q, 1924.. v J. s. TOWNSEND SAND CUTTING AND SCREENING MACHINE Filed Dec- 19, 1921, 3 Sheets-Sheet 2 J. S. TOWNSEND SAND CUTTING AND SCREENING MACHINE 3 Sheets-Sheet 5 Filed Dec. 19] 1921 flaerzz im afmmm Patented Dec. 30, 1924. I

, UNI! ,1

JOHN s. TOWNSEND, or HARVEY, ILILINoIs; ASSIGNOR To WHITING CORPORATION,

OF HARVESL'ILLIN OI S, A

SAND CUTTING AND Application filed December less mixed with pieces of rough iron which.

have to be removed, is leftvcluttered over the foundry floor. In order to prepare this sand for another use in a molding operation, it is necessary, as well understood inthe art, to add a certain proportion of new sand, certain amount of moisture by the addition ofwater, and to mix the whole into a uni-' formly mixed mass of sand arranged in piles forconvenient'use -so that the molder can 7 apply it in the preparation of new molds for new castings. .essary that all of the sand be aerated so 2 that there is a certain amount of air ads jacent each sand particle in, the mix so that the composite sand in the new mold has scattered through it a certain percentage of air spaces, through which the gas from the molten metal'of the new product being cast, can escape. It is well understood in the art that where sand not so properly aerated is used, defective castings may result. I v

The object of this invention is to provide a power driven machine "adapted to pass over a foundry floor and properly cut, mixand aerate the sand, such for instance as the machine'shown completely in my prior 40 United States patent application, Serial No.

$80,714:,filed May 12, 1920 with an addi tional cutting "and mixing mechanism located in advance of the path of travel of the machine proper, which at'that point tho-roughly cuts, mixes and aerates the sand which is in the path of travel of the machine.

More particularly this invention is, in certain features, an improvement on a machine of this particular class shown in my prior patent application, Serial No. 461,161, filed April 13, 1921.

The additional device referred to at the front of the machine not only. does away with the necessity of using hand labor to Furthermore, it is neccut a path through the sand on the floor CORPORATION or ILLINOIS.

SCREENING MACHINE.

'19, 1921. Serial n. 523,257.

for the machine proper, as has frequently been required heretofore in the prior art, but gives the sand, in the very operation of preparing the path for the machine proper,

an additional cutting, mixing and aerating, thereby greatly improving the finished prod- Ect delivered by'the machine in rows on the oor. 1

In actual practice, a, machine equipped with the device of this invention cutting and aerating the sand in advance of the chines of said last mentioned prior patent travel of the machine, as well as in the maapplication, increases about twenty per cent the percentage of perfect castings produced by the use of sand prepared by the same type of machine when not equipped with the improved devices of this invention.

In the feature of this device which most closely approximates theisecond application heretofore referred to, the invention consists in so forming and spacing the blades of the sand cutting wheel at the front of the machine that when the device is operated at pro er speed, practically all of the sand wit in reach of the cutting cylinder or set of disks, is thrown into the air, aerated and transferred.v towards the center of the machine ,fordelivery into the elevator buckets of the machine, without any substantial portion of the sand being thrown over the cutting wheel or cylinder and back onto the floor without passing up through .the machine and being further cleaned.

The invention further consists in the use,

in": connection with the sand cutting blades at the front of the machine, o-fwheel devices of different selectable types for holding the sand cutting blades sufficiently clear of the floor over which the machine travels so that they do not-strike the floor, and yet causing them to travel exceedingly closely to the floo-r, this for special reasons which willbe hereafter pointed out in the specification.

- The invention further consists in-novel .spring mounting for the elevator mechanism of the machine, by which should-a cutting blade at the front of the machine actue ally strike the floor, the jar of this action is taken up sufliciently to allow the elevator to move vertically with reference to a truck or main machine which carries it, insteadof lifting the front Wheels of the truck off from the floor, as has heretofore frequently happened in prior devices not equipped with this novel cushioning device.

The invention *further consists .in many features and details of construction which will be hereafter more fully set forth in the specification and claims.

Referring to the drawings, in which hke numerals designate the same parts throughout the several views v Fig. 1 is a side elevation of the main parts of a complete machine-illustrating" this invention in its preferred form;

Figure 1 is a detail View 'of the spring mechanism for permitting the elevator to move upwardly with referenceto the truck mechanism proper, as heretofore referred to in the opening statement;

Figure 2 is a front end view, considerably enlarged from Figure 1, showing the'sand cutting wheels located at the front of the machine;

Figure 3 is a developed plan View, showing the angular relationship of successive blades at one side of the elevator which-cooperate serially in the operationof the device; a Figure 4 is an imaginary picture to illustrate the effective working relationship of the same set of blades as shown in Figure 3, the actual spacing of the blades which conveying cylinder;

is shown in Figure 3 being-entirely omitted;

Figure 5 is a perspective view'of a conveying wheel located at the end of the same F gure 6 is an end viewon the line 66 of Figure 2, showing one blade of each pair referred to in relation to other blades with which it cooperates;

Figure 7 is a detail end view corresponding to the right hand end of the sand cutting and conveying cylinder of Figure 2,

- showing a modified form of whe'el substituted for the deviceof Figure 5;

V Figure 8 is an end view-taken on the line 88 of Figure 7;

, Figure 9 isan'other view exactly like 'Figure 7, exceptthat another modified form of wheel. is substituted for the device of Figure 5; and

Figure 10 is'an endview. taken on the line 10-10 of Figure '9.

One conventional type of machine to which the present invention may be applied has a main frame 10 carried by supporting Wheels 12 and 14. On frame 10 is a rotatable riddle 16, whose main function is to do the final mixing and. aerating of the sand. On the front of the machine, the left hand end as shown in Figure 1, is a sprocket chain 18'-'buckets 20, elevator which carries .collected portions of sand 22 up from the foundry floor and delivers it into the -,-riddle l6.

This elevator mechanism 18 20.'is carried by two sprocket wheels 24 and 26located on shafts 28 and 30, the former .posi.

tivelypositioned with reference to parallelside frames 32, the latter carried by bearing supports33 interfitting with the frame members 32 in such manner that the frame members may slide vertically of the shaft 30. Depending from and rigidly secured to'the'lower one of these members 30 just described is a screw 34 freely reciprocable through' a. cross connecting member 36 be tween the frame members 32. On the screw 34,-below member 36, is an adjusting device, in the particular'case here illustrated a nut 38, while above-the'member36 is a spring '39 enclosing the screw and abutting,

against the lower-member 33, whereby it is possible for theframe 32 and attached parts to move upwardly against the action of spring 39 when, dueto some unforeseen condition, the sand cutting mechanism to be hereafter described strikes the floor 40.

vention, to convey the entire machine in either direction, it traveling to the left as viewed in Figure 1, in the act of cutting and screening portions of the sand 22. In so operating to throw sand the buckets .20 directly engage and scrape up sand 22 which is in front of them, as the machine travels over the foundry floor 40, but as the path cleared by these buckets is, for the reason uststated very much less than the width of theentire machine, articularly as evidenced by the wheels 1 passing over. the floor and for which a path is to be cleared, one of the problems to be solved is to provide means which will efiectively cut and aerate sand lying in the path of travel of the machine on'each side of the path traveled by the lower end of the elevator mechanism, and deliver it in well aerated form to the buckets 20, which happen to' be at the bottom ofthe'elevator at a given moment so that all of the sand which is initially across the whole path of travel of the machine can and will be elevated by the narrow elevator mechanism shown, and finally delivered to the riddle 16.

In accomplishing the object just set forth,

shaft is made of a length, as shown in Figure 2, greater than the entire .width of the,.mac'h1ne, its ends being sustained by -bra.ckets 46 suitably secured to. the side frames 32. d On the end portions of this shaft 28, outside of the frames 32, are placed a series of cutting blades or arms adapted to als followed by the letter a.

'ticular case here illustrated, the single blades cut and aerate the portions of sand lying on the fioor in the path of travel of the machine and between the elevator mechanism and the outer ends of the brackets 46. One of the special objects of this invention is to so proportion the angularity and the spacing of successive blades or arms which cooperate with each other that when the machine operates at its normal, standard speed, all of the sand picked up by this blade mechanism will be retained in the air or otherwise adjacent to the blade mechanism while it is being conveyed over to the center of the machine and delivered into the elevator mechanism, instead of some of the sand being thrown outside of the control of the mechanism and returned to the floor 40 without passing up the elevator to the riddle 16. as is apt to occur in a device in which all of the blades on this shaft 28 are exactly alike.

In the preferred form of the device shown in the drawings, each end of the shaft 28 is equipped with corresponding but oppositely disposed sets of blades arranged in pairs, one blade of each pair being designated by the numerals 1 to 8 inclusive, and the opposite blade of each pair by similiar numer- In the parof Figure 6 which cooperate with each other in the operation of sand throwing, are placed as shown in Figure 3, 135 apart. In the structure shown in Figure 2, there is placed between the blade 1 and the outer end of bracket 46, a conveying wheel shown in perspective i'n Figure 5, made upvof two semicircular, angular blades 47 and 48, so positioned on the shaft that in the travel of the machine over the floor 40, one of these members moves sand slightly from the end of shaft 28 toward the elevator. into reach of one of the blades 1. and the other performs'the same function for the opposite blade 1. Aside from this conveying func' tion, the device 4:74:8 acts as an ordinary wheel to sustain the lower end of the elevator with the tips of the blades 1 to Sinclusive a fixed distance above the floor 40 so that they may cut close to the floor and thus pick up substantially all of the sand thereon without danger of striking the floor and thus throwing the elevator upward. against the action of the emergency spring 39, an action which is not desired.

Figure 7 shows an alternative construction, differing from that of Figure 2 in that a plain wheel 50 is substituted for the device 47-48, this wheel being freely rotatableon the shaft 28. In the alternative construction of Figures 9 and 10, another wheel 52 is substituted for the wheel 50 and differs from it only in that it .is rigidly secured. to the shaft 28 by any suitable means, as for instance the key 54. These the same function as wheel 4c7il8 in sustaining the mechanism so that the blade ends cannot strike the floor 40. The structure of Figure 9, with the wheel rigid on the shelf, has the advantage over that of Figures 7 and 8, in that the power which is in shaft 28 as the machine operates causes this wheel to out its own way through sand 22, as the machine works, whereas the wheel 50 loose on the shaft, has the advantage of not being under powerful, continuous rotation and therefore does not wear out through being rotated through the sand, as is the case with wheel 52. ,The use of these wheel mechanisms 4748,50 and 52 is particularly important in a machine of this class for the following reasons When a foundry floor is left covered with hot, previously used sand, which is to be cut and aeratedfor re-use. the workman goes over the sand covered floor with a hose and, in so far aspossible. wets and cools down the sand by liberal application of .water, but as a matter of fact, this water,

even when delivered under comparatively high pressure, never reaches the bottom of it is a certainty that if the untempered sand left on the floor tre ts into amold in which casting is being done. it will spoil the casting. The device of this invention, particularly the use of the wheels described, allows the blades 1 to 8 inclusive to so thoroughly clean the floor of untempered sand that when tempered sand is delivered on toppf this thin layerof untempere-d sand, the moisture in the tempered sand actually tempers this thinlayer, and prevents any injurious result. This causing of the blades 1 to Sinclusive to travel very close to the floor has the further advantage that in actual practice, they pick up and carry over to the elevator a very much greater proportion of the sand on the floor below the actual tips of the blades than when theblades do not travel so closely to the floor.

In the operation. of the device, assume v der these conditions, the two outside sets of 7 blades 1 to 8, with or'without the assist.- ance of the wheel mechanism 47 48. tend to take. the portions of sand at the opposite ends ofthe sh'aft28'and because of the angularity andpositioning of the blades 1, v

convey it towards the elevator mechanism without throwing it very much intothe air, but nevertheless throwing it sufficiently so that the portions of sand so thrown dofall into the path of travel of the next succeeding blades 2, which in turn convey it to blades 3 and 4 and 5, which are in the particular case here shown, all of vthe same angularity; The sand thus conveyed from the ends-of the shafttowards the elevator at the center, of the'shaft, increases in volume at each blade towards the center, and; it becomesnecessary at about blade 6 to change its angularity, as shown, which angularity is carried out in blades 7 and 8, tothrow this increased volume of sand into I the air for aerating purposes and to convey it'along' to the elevator buckets 20, In actualpractice, the blades 1 are set at a very small angular position.) As shown in Figure 3 the blades 2.+5 are set at about, degrees and'the blades (Ste 8 at about 45 degrees; The result of-this construction is that when operated atproper speed, the,

blade :mechanism on shaft 28 actually aerates and conveys the sand from the sides" of the,machineifintogthe elevator without' throwing anysubstantial portion of the sand once cut' and lifted, back onto the floor-without its reaching the elevator.

'VVhen thesand' reaches the elevator, it is conveyed upwardly by it to the riddle 16,

screened in. the ordinary way and delivered back onto the floor.

.Figure 4' is intended as an illustrative development showing the effective corela- .tionshipfof the different blades of Figure 3,

as it m ght be imagined they'would operate if placed closejtogether, it being noticed thatlgthe blade-at the top of the figureis almostiat right angles to the axis of shaft 28,,a'nd the; blade at the bottom of the the'axis of that shaft. A Q;'Ihe elevator mechanism is propelled by figure closely approaches-being parallel to any convenient source of power, that convenw tionall'y shown being a driving chain 42 and- .'dI1VeI1il)y a motor gear mechanism 58 supplied with power in any conventional manher. not entering into this invention and therefore not shown. a--The elevator mechanism with the sand collecting device deactual operation show the spiral mechanism l-to':8 completely enveloped in a thick cloud of sand which isbeing carried by the Blade mechanism from the outer ends of the shaft over to the elevator, and ultimately deposited therein.

It is well understood in the artthat molding sand is made up of particles of so-called sharp sand, mixedwitha certain percentage of clay, or other binding material, which makes the molded sand stick together in the molding operation. When this sand has been usedin casting, these particles of sand tend to stick together in comparatively-hard lumps and the successive blades 1-8 inclusive, referred to perform the added function, of successively batting or pounding such small lumps of sand-and'clay in their path of travel to the elevator, thus insuring their more thorough disintegration than is possible where they are only struck or handled once. measure accounts for the very satisfactory product of aerated sand use of this invention.

i VVhat I claim is:

1. In mechanism of the class described, a rotatable shaft, a plurality of cutting blades along said shaft, arranged. angularly to each other-around the shaft in a spiral of such a form that beginning with one end blade each blade picks up sand in the'plane of its rotation and throws it into the plane of rotationof-the next blade, each of said blades being placed atan angle to the axis of the shaft/and certain of them varying progressively 'in angularity with. reference to the axis of the shaft from the first blade to the last,. and a motor operating the parts at the-necessary speed to handle foundry sand, partly in the air.

It is believed that this in a large produced by the 4 2. In mechanism of the class described, a

rotatable shaft, a plurality of cutting blades along said shaft, arranged angularly to each other around the shaft in a spiral'of sucha form that beginning with one end blade each blade picksup sand in the plane' of its rotation and throws it into the plane of rotation of the next blade, each of said blades being placed at an angle to the axis of the shaft and certainof them varying progressively-in angularity with reference to the axis of the shaft from the firstblade to the last, the angular distance between the blades around the shaft being approximately 35, and a motor oper ting the parts at the necessaryspeed to handle foundry sand,

a form that beginning with one end blade I each blade picks up and in the plane of its rotation and throws it into the plane of rotation of the next-blade, each of said blades being placed at an angle to the axis of the shaft and certain of them Varying.

progressively in angularlity with reference to the axis of the shaft from the first blade to the last, the first blade being at a very slight angle to a plane transverse of the shaft, the last blade at an angle of approximately to the same plane; and a motor operating the' parts at. the necessary speed to handle foundry sand,,pa'rtly in the air.

4. In mechanism of the class described,

ranged that each blade, beginning with the one most remote from the elevator, throws sand cut by it towards the elevator and into the path of the'next succeeding blade, said means at the cutting edges of the blades being angularly disposed to parallel planes,

transverse to the axis of saidshaft and varying progressively in angularity from the outer end of the shaft to the elevator mechanism, for the purposes set forth, and a motor operating the parts atthe necessary speed to handle foundry sand, partly in the all.

5. In mechanism of the class described, a machine adapted to travel over a foundry floor, an elevator capable of carrying sand from the floor into the machine, a sand cutting and aerating element at the side of the elevator adjacent to where it passes along the floor, capable of picking up sand at the side of the elevator and by repeatedly strike ing it while in the air, transporting it largely in the air from the side of the elevator to the elevator, said picking up and strikingmeans consisting of a series of blades spaced apart longitudinally along and circumferentially around said sand cutting and aerating element and varying in angularity to each other in proportion to the amount of sand along said'element to be cut, aerated and transported to the elevator, and a motor operating the parts at the necessary speed to handle foundry sand.

6. In mechanism-of the class described, a truck carrying a sand receiving member, an elevator mechanism having one end adjacent to-the floor and the other end delivering-to sa'i-d sand receiving member, sand cutting 55' devices on the bottom of the elevator for delivering sand to the elevator, means for propelling said sand cutting devices and elevator, and yielding mechanism between the elevator and truck permitting vertical movement of the elevator should the sand cutting devices accidentally engage the floor.

7. In mechanism of the class described, a truck carrying a sand receiving member, an

elevator mechanism having .one end adjacent to the floor and the other end delivering to said sand receiving member, sand cutting devices on the. bottom ofthe elevator for.

delivering sand to the elevator, means for propelling 'said" sand cutting devices and elevator, and spring controlled yielding mechanism between the elevator and truck permitting vertical movement of the elevator should the sandcutting devices accidentally engage the floor. I

. 8. In mechanism of the class described, a-

truck carrying a sand receiving member, an

elevator mechanism having one end adjacent to the floor and the other end delivering to said sand receiving member, sand cutting devices on the bottom of the elevator for delivering sand to the elevator, means for propelling said sandcutting devices and elevator, spring controlled yielding mechanism between the elevator and truck permitting vertical movement of the elevator should the sand cutting devices accidentallyengage the floor, and wheels on the bottom-of the- F elevator sustaining the cutting devices a fixed distance above the floor. I

9. Inmechanism of the class described, a

truck carrying a sand receiving member, an

elevator-mechanism having one end adj acent to the floor and the other end delivering to said sand receiving member, sand cutting elevator and truck permitting vertical movementof the elevator should thesand cutting devices accidentally engage the floor and wheels on the bottom of the elevator Sustaining the cutting devices a fixed distance above the floor.

10. In mechanism of the class described, a truck carrying a sand receiving member, an elevator mechanism having one end adjacent to the floor and the other end delivering to said sand receiving member, sand cutting devices on the bottom of the elevator for delivering sand to the elevator, means for propelling said sand cutting devices and elevator, and wheels on the bottom of the elevator sustaining the cutting devices a fixed distance above the floor.

11. In mechanism-of the class described, a.

floor engaging wheel adapted to support an elevator and made up of a plurality of segmental parts, each placed .angularly to the wheel axis adapted to convey sand or the J OHN S. TOWNSEND. lVitnesses i L. D. REED PAUL W. IiIELFELDT.

like sidewaysof the wheel as the wheel ro-

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