US2538770A - Core box filling machine - Google Patents

Description

Jan. 23, 1951 T. N. FEA

CORE Box FILLING MACHINE Filed Nov. 1, 1948 /NvE/vTo THOMAS N. FEA by" @ab A To/vfv Patented Jan. 23, 1951 U NI TED rS TA'I'EES PATENT O F F l C E 2,538,770A CORE BoXQFmLINeM-Acnmn Thcmas-N.`Fea, Granite City, Ill.

.Application November 1, 1948, Serial No..57,757

This invention. relates. generally to `machines for lling .core boxes :used in found-ry work, and. more particularly toy such an apparatus4 employ,- ing compressed air as the rammi-ng. or filling medium for the core boxes.

-One of the principal, obje-cts of thisv invention is to so construct a mechanism of the kind aforesaid, with a sand-receiving chamber in communication with` said core box, vand wherein the air blast employed to force the sand in the chamber into the core box will be `aided and. assisted hy a secondary air blast .directed at an angle to` that of the main blast, te'thereby break up any clods or cakes of sand within .the said chamber,A with the result that free and rapid movement oisand into the core boX .is obtained.

A second object of my invention is to provide a deviceV of the kind described, wherein there will be two separate blasts for actuating theA sand in the chamber into the core. box, one of .saidv blasts being the principal mover and directed downwardly through the sand toward the .crore box, and. the other blast being auxiliary land directed substantially transversely .through the sand adjacent the lower partof the chamber and releasing it from adherence to .the chamber wall and breaking cakes or. clods 'that might have been formed, thereby tending. to make 'holesl or openings through. the sand adjacent the bottom thereof and accelerating free movement of the sand toward the .core box.. Y

Another objecto the invention is to construct a` machine of the kind described, that may he relatively small in size and cost and that will operate efficiently on a small supply of core sand c placed. therein, and wherein the frequency of fillings or replacements of sand are at a minimum,v inasmuch as there need not be a -large head oi sand in the sand chamber .in order to. operate the device eihciently.

A further object of my invention is to provide a core box ller 4of the kind set forth, Aemploying a .sand hopper" from which sand is withdrawn from time to time into a sand chambenntcwhich. the air blasts are directed,x and wherein there lwill be a valve element for controlling the .transfer of sand from the hopper to said chamber. and which will also serve asa closure forthe chamber to seal the latter to retain the required ai'r `pressure therein.

An vadded object of my invention is Ato construct a device of the kind hereinbefore mentioned, that will have relief or` safety means as part f its pressure sealing member, to vent 'the sand chamber whenever the air pressure Ytherein in excess-of a predetermined value.

The invention has .among its. other objects the production of a filling machine of the kind `described that, will beI relatively `simple and economical in construction. and operation, have relatively few parts? and which will be otherwise satisfactory .andecient for use wherever deemed applicable.

Many other vobjectsand advantages of the constructonlherein .shown and described, will be obvious..to .those skilled .in the. art to which this invention appertains, .as will be apparent from thev disclosures herein given.

To thisend,y my invention. consists in the novel arrangement,. construction. and combination of parts herein shown and described, and the uses mentioned, as. will he more .clearly pointed out in the following specication.

In the drawings, wherein like reference characters. representv like or corresponding parts throughout 'the views, y i

Figure l is a vertical cross-sectional View, showing, the mechanism;

Figure Zisa side elevation of the same, having the core box and its lift and the sand hopper, omitted;

Figure is an inside plan view of the chamber dloor;y

Figure 4"i's a cross-,sectional detail showing the relief vent in the door; and

Figure 5 is la transverse cross-sectional view, taken substantially yalong the line '5-5 of Fig. l.

Referrng'more `particula-fly to the drawings, wherein I have illustrated a preferred embodiment of my invention, there is showna core ling tn'rechansm useful in foundry operations when `making castings.

Althouglrli it' isnot' newl to use air pressure to force the sand into the core vboxes, the machines are lvery costly; heavy and bulky, bothersome to use, and require much eiort on the part of the operatoryespec'ially in constantly keeping enough sand' 'in the'marehine'tc ma-ke'a heavy head found necessary 'its operation.

Toobviate these defects, I 'have so constructed amachine that will operate on extremely light head oisand', visofsmall size, and relatively easy to operatel: indicates-aplatf'orm or table set at `any suitahle height and having openings, 2 and which forms 'a Vblower plate through which the core sand is air blasted-intoy a core'bo-x 3 placed therebelow` This core'fbox'be of any suitable or preferred tsire sha-pe; as may be required from. time to time according to the needs of the foundry, :and should be vented at ii through its bettcm so asta'thatthe'sand will be 'coml pletely transferred into said box without undesirable air pockets therein.

A sand receiving blower chamber 5 is arranged on said table to extend upright therefrom, with its lower end enlarged'relative to its upper end, so as to appear as a truncated member, said lower end sealed against said table, except for openings 2 through the blower plate of the table, so that air or sand in the chamber will be forced downwardly through said openings. y

A pipe or conduit 6 leading from a suitable source of compressed air, empties into the chamber through a top opening 1, there being a tank or storage element 8 if desired to build up suffcient volume of air to properly operate the device. A valve 9 is placed somewhere in the line 6 at some point where it will be convenient and easy to operate manually, to therebyT control the passage of the air blast from said line, said valve being of any suitable type for the purpose. The pressure in this line should be suiiicient to actuate the sand that is in the chamber, downwardly toward the core box that is in place below the blower plate, and although I do not intend this as a limitation, I have found that a line pressure or 1GO pounds has been found satisfactory with the core boxes tried in the machine. Of course, the pressure may be made higher or lower as required, or as circumstances warrant.

A sand hopper l5 is arranged to be mounted on said sand chamber or adjacent thereto, in which the supply of core sand is maintained and from whence it may be withdrawn into the sand chamber from time to time as needed, said chamber having an opening l! through its upright side wall, and said hopper having an open discharge outlet I2 spaced from said opening and in registry therewith.

Obviously a closure is needed to seal the air pressure within the chamber while the sand therein is propelled into the core bornand for this purpose I have arranged a sufficiently strong and durable door i3 pivoted adjacent its circumferential edge at i4, to said side wall of the chamber, and provided with an operating handle I5 for rotating the door about said pivot. This door rits between said opening and discharge outlet to serve as a seal for said chamber as well as a gate valve for the hopper. It is not necessary that the door actually engage the hopper outlet at any time, because the sand in the hopper is slightly moist so as not to be completely freerunning, and therefore I have found that a clearance of about le" between the door and the hopper is satisfactory, and will be of service in minimixing wear and abrasion therebetween.

In order to seal the door satisfactorily againstv the air under pressure in the chamber, I have interposed a yieldably compressible gasket element it therebetween, as for instance mounted on the door to encircle the chamber opening when the door is closed, this gasket lying partially within a continuous groove or channel .on that face of the door opposed to the side wall opening. It is necessary to hold the door against the chamber with suicient pressure to keep it."

sealed against the working pressure of the air in the chamber, and to do so I have arranged an operating handle Il mounted adjacent said door.- and rotatable relative thereto and provided with one or more locking abutments or cams I8 for progressive engagement with the door after clos-- ing of the latter. Y v- As a safety feature and to hold the air pressure in the chamber to a predetermined value,

vent I9 may be provided at the seal between the sand chamber and door, as by the relatively narrow groove out in the face of the door that is opposed to the chamber opening and which extends substantially radially from the inner portion of the door to the periphery of the latter beyond said gasket. The gasket will seal said vent under normal conditions, but upon reaching an excess of a predetermined air pressure within the chamber, said air will leak past and under said gasket, travelling in said groove to blow harmlessly into the atmosphere and at an angle that may be made to be away from the usual position of the operator.

It may be desirable that the core box be held rmly in place in set position immediately below the blower plate, and although there may be various mechanisms for accomplishing such a result, I have shown a very simple manner of so doing, as for example by having a vertically movable arm 2l) with its upper end carrying a core-box platform 2l thereat and with its lower end pivoted to the end of a pivoted lever 23 carrying an adjustable weight'22 at its other end.

There is great tendency for core sand to form clods and cake and to render the vsame more readily flowable some form of agitator or vibrator (not shown) may be mounted to shake the sand hopper, and it is also necessary to overcome this caking tendency in the blower chamber' too. Otherwise, an exceptionally great pressure head must be maintained in the chamber, causing much trouble in maintaining the high sand level in the same, but also needing a much larger mechanism for the purpose.

I have found, however, that if an auxiliary blast of air is directed through the lower body of sand within the chamber, substantially laterally or transversely, the cakes or clods are broken upA and causes openings to be formed in the sand adjacent the chamber bottom, thus accelerating the travel of the sand downwardly into the core box.

This auxiliary line is indicated at 2li, controlled by a suitable, manually controlled valve 25, and is arranged in any desired manner, as by a regulator or other means (not shown) or by the reduced diameter of the pipe as compared with that of the air line G, so that the pressure discharged therefrom is less than that through the main pipe 6. A conduit 28 is arranged to lie within the lower portion of the chamber and eX- tend about the interior periphery of the latter,

l transverse direction.

When the air is blasted through such an auxiliary member, not only are the cakes and clods broken up in the bottom of the sand within said chamber, but there is a tendency to make pockets in that portion of the sand, and thereby accelerate the movement of the sand from above toward the core boxes.

In operation, and assuming that the core box is.

irl-proper position below the blower plate of the chamber, and that the closure door has been closed tightly, the valves from the main line and the auxiliary line are opened one or more time depending `:upon the size of the core Opernhg s atthe time, and thus the main air blast will be directed downwardly through the body of sand within the chamber to actuate said sand tov/aid the core box, while the auxiliary air blast shoots across the bottom or the chamber through said sand, breaking up any cakes therein, and permit` ting the sand to fill the core box. As soon as the core box is lled, thepressure within the chamber will exceed the predetermined value originally set, and the excess will vent through the safety vent in the door of the machine. The core box may then be replaced by another, and the same operations gone through again. From time to time, 'the door must be temporarily opened to permit sand to rlow into the chamber from the hop per, and the door is then 11e-closed to normal operative position.

Having thus described my invention, it is obvious that various immaterial,modica'tions may be made in the same without departing from the spirit of my invention; hence do not wish to be understood as limiting myself to the exact forni,

arrangement, construction and combination of parts herein shown and described, nor uses menn tioned, except as limited by the state or the art to which this invention relates, and by the claims hereunto appended.

What I claim as new and'desire to secure by Letters Patent is: 4

l. The combination with a source of compressed air and a core box, of a chamber opening into and arranged intermediate the two and communicating with said box at its lower end, a sand hopper mounted adjacent said chamber and opening into the latter for controlling passage of sand through opening into said chamber, conduit means communicating with said source of compressed air and the upper end of said chamber y for admitting the air to blast downwardly onto the sand in said chamber, and additional conduit means communicating with said source of compressed air and the lower part only of said chamber for directing an air blast substantially transversely through only the lower portion of the body of sand in said chamber'.

2. The combination with a source of compressed air and a core box, of an upright air pressure chamber therebetween and communicating with the same, of a sand hopper adjacent said chamber andV emptying into the latter, means for controlling the flow or sand from said hopper into said chamber, conduit means for communication between said source of compressed air and the upper portion of said chamber for admitting said air downwardly into the chamber to force the sano'. therein toward said box, and separate conduit means communicating between said source of compressed air and the lower portion only of said chamber to admit an air blast substantially transversely across the lower portion only oi said chamber to blow the sand inwardly of the upright enclosing wall of said chamber with sufficient orceto break up the lumps of sand therein.

3. The combination with a source of compressed air and a core box, of an air pressure chamber opening onto and arranged intermediate said box and source and communicating with said core box therebelow, conduit means between said source of compressed air and the top or" said chamber, a sand hopper, means between said hopper and chamber for controlling the passage from said hopper to said chamber, a valve controlling passage oi said compressed air through said conduit means and admitting said air downwardly through said chamber, an air duct between said source of compressed air and said chamber and extending substantially about the inner periphery of the latter and having outlets directed substantially transversely across the lower Vportion only of said chamber, andra valve in said last-mentioned duct and controlling admission of said air into said duct to discharge the same through said outlets only and force said sand inwardly thereat toward the center oi said, chamber.

4. rlhe combination with a source of compressed air and a core box, of a sand hopper having a discharge outlet, a chamber member communicating with said source of air supply and arranged intermediate said source of air supply and said box and communicating adjacent its lower end with the latter, said chamber having a side opening in registry with and spaced from said discharge outlet, a door member insertibly movable into place etween said opening and said outlet to control passage of sand therebetween, a resilient endless gasket between said door member and chamber member, means for forcing said door toward said chamber to compress said gasket substantially uniformly throughout its length and form an air seal for said chamber member, and a relief vent groove transversely across one or said last-mentioned cooperating members beneath said gasket so that said gasket is less tightly compressed at said groove than elsewhere of its length and whereby the gasket will be unsealed at said groove before at any other portion whenever the air pressure within said chamber exceeds a predetermined amount.

THOMAS N` FEA.

REFERENCES CITED The' following references are of record in the file of this patent:

UNITED STATES PATENTS France Sept. 12, 1932

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