US587031A - adams - Google Patents

Description

2 Sheets-Sheet 2.

(No Model.)

S. J. ADAMS.

METHOD or ANDIAPPARA-TUS FOR FORMING SAND MOLDS. No. 587,031.

Patented July 27,1897.

' a mold is necessarily liable to possess imper- UNITED STAT S PATENT "OF ICE.

STEPHEN JARVIS -ADAMS, OF ll'lTSBUHG, III XNS YLYANIA.

. METHOD OF NoA PARATus FOR FORMING SAND MOLDS.

. SPECIFICATION forming part of Letters Patent No. 587,031, dated July 2'7, 1897 Application filed. November 23, 1891. Serial No. 412,857. No model.

To all whom it may concern- Be it known that I, STEPHEN JARVIS ADAMS, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have ini 5 vented a new Enid useful Improvement in the,

Method of and Apparatus for Forming Sand Molds and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to an improvement in apparatus for forming sand molds, its object being to produce a mold in which the sand is closely compacted and free from spongy parts and small cavities or pockets, such as would lead to imperfections in the castings formed therein.

' )ne of the processes of forming sand molds heretofore experimented with consists in carrying sand to a point elevated above the flask containing the patterns and allowing the sand to descend by the force of its own gravity into the flask below, the object of the process being to compact the sand densely all around the patterns by the velocity acquired during its descent. One seriousobstacle is encountered in the practical operation of this process due to the air confined within'the flask.

\V hen thesand is permitted to descend inbulk from a height above the flask into said flask, as there is no way of escape for the air within said flask except from the mouth or open upper end of the flask, the air acts as a cushion for the falling body of sand and its velocity or force is seriously impeded, and besides leaving spongy places in the channels where the air has escaped on its way out of the flask it also forms small pockets or aircavities in the lower part of the mold around the base of" the patterns by the air which could not escape. A casting formed in such fections through the metal entering such cavities or pressing back the sand in such spongy placesand so forming swells or enlargements thereon; The object of my invention ,is to obviate; this difliculty in connection with the practice of this and similar methods of for1ning molds, and thereby produce a mold free .froin'suchimperfections. I

To these ends my-invention consists, generally stated, in setting a bulk of sand in motion and causing it to e'nter the receivingcavity in bulk, and at the same time providing i'ree escape of air from such cavity to permit the sand to pack evenly and solidly therein.

It also consists in applying pressure to a body of sand contained in a holder, so as to project it into the flask.

It also consists in combining means for setting a bulk of sand in motion and guiding it to theflask \vitha flask having openings leading from itssand-receiving cavity, so that air may have free escape and the sand be properly compacted.

It further consists in arranging within the flask a projection having an inclined face which surrounds partor all of the pattern and which is adapted upon the descent of the sand to direct the-sand against the body of the pattern, so as to pack the sand closely against the pattern.

It also consists in other improvements, as hereinafter set forth.

To enable others skilled in the art to make and use my invention, I will describe the same more fully, referring to the accompanying I drawings, in which- Figure 1 illustrates a flask containing patterns, showing the lower end of the chute arranged to direct the sand into the same. -'Fig. 2 is a plan view of the flask: Fig. Sis asec-. tional view of the flask, showing an improved method of projecting the sand into the flask; and Fig. -l is a like. view showing another means of discharging the sand in-bulk into the flask, the means illustrated in the latterview forming the subject of another applica tion of even date herewith, Serial No. 412,860; and Fig. 5 is a view of a core-box, illustrating the application of the inventionto the same.

Like letters of reference indicate like parts in each view. I

In practicing my invention where the bulk or body of sand receives its velocity by dropping through the chute the lower end of such chute isshown at a, such'chute acting to direct the sand into the flask, the sand being dropped the proper distance to give the necessary velocity for packing within the flask. Such chute forms a good illustration of the manner of feeding the sand in bulk, such as bydropping or gravity, but the sand maybe fed led in bulk with the necessary force to compact it in any suitable way, one of which is included in this application. The flask Z) is located directly under the chute a, said flask containing the patterns 0, which, for the pursuch cavities, these openings being formed 'either in the flask, the base-plate, or in the patterns, which in such cases are hollow. Several examples of these escape openings or outlets are illustrated, the base-plate (1 being provided with openings d, while the walls of the flask b are provided with. the openings 1), which openings are illustrated as formedadjacent to the base-plate d, which is the preferable position for the same, though the openings may extend toward the upper endof the flask, and like openings 0 are shown at the bases of the patterns. For some purposes the patterns may be supported on pins 0 resting on or entering seats in the patternrplate, and the air permitted to escape betwgeuthebaseofthc.pattern and the pat tern-plate; It will be understood that the object of such construction is to provide free escape of the air from the sand-receiving cavity when a bulk 'or body of sand sufficient to .fill the same enters with the velocity necessary to compact the mold, and that while it is essential that there should be these openingsat or near the base of such sand-receiving cavity these openings may extend asfar above the base as it is found desirable. It

' 'will be noticed that the flasks are formed inreceiving cavity and materiallyassist in packingthesand against the patterns. :FOI this same purpose I also prefer in some molds to employ the internal guide pieces or rings (2, projecting into the said receiving-cavity,

.. rings such as illustrated in the drawings being generally employed with tubular or circular. patterns, though for some patterns of other shapes sectional .picces extending up from the base-plate could of course be employed. These conical rings or guide-pieces extend up from the base-plate within the flask to a suitable, height and have their faces inclined from the top ridge or apex thereof toward the patterns, so as to direct the sand in its descent against the bodies of the patterns and cause a more perfect compacting thereof in the particular place where it is desired to compact the sand firmly. Air-openingsfinay also be formed at the base of such projected pieces.

In practicing my invention with theapparatus above described the operation is practically as follows: The flask Z) is arranged directly under the chute a and the sand which is held in bulk at the upper end of the chute is allowed-to descend through the same, the sand dropping a suflicient length to acquire the necessary velocity to pack firmly within the flask where the bulk or body of sand'enters the same.

Instead of permitting the sand simply to drop through the "chute or guidway a I in some cases employ simply a short guideway g, as more particularlyillustrated in Fig. 3, above which is the sand-holder'h, which is filled with sand, the upper part of said sandholder being closed, and I apply pressure in any suitably way to the body of sand to project it into the flask. For this purpose I may either through a pipe 7L2 introduce air under considerable pressure or I' may through such pipe introduce a mixture of gas and air, which maybe exploded by a jet entering the space above the sand through pipe 71?, and so generate sufficient force to impel the sand through the guideway into the flask. In such casesthe doors 7L3, closing the lower ends of the sand-holder h, are hinged and are provided with springs 7L of sufficient force-to hold the doors closed when the bulk of sand rests upon them, but are yielding when the pressure is brought upon the sand, so as to be forced out of the way and permit the bulk of sand to be projected into the flask below the same.

\Vhere the sand is projected in bulk from the. holder, the result is practically the same, a body of sand sufiicient to fill and pack the flask being set in motion by the pressure created above it, such as by the air-pressure or by the explosion of the gas above the same, and so ejected from the holder into the flask. In either such case a bulk or body of sand sufficient to fill the flask and be compacted therein enters the cavity of the flask with suflicient force to compact itself within the flask and around the patterns, and when it enters the same the air which is contained within the sand-receiving cavity finds free escape therefrom through the several escapeopenings leading from such cavity, either through the flask-walls, the base-plate, or patterns, so that all liability of the formation of air-pockets on account of the confining of air. within the flask, or the formation of soft spots is overcome, practically all resistance to the bulk or body of sand being removed, and it can therefore compact itself by its velocity firmly within the sand-receiving cavity and around the patterns. During this action the sand which strikes the inclined rings or in-.

clined faces e will be directed thereby against the patterns and the proper compacting of the sand. at such points will be obtained. At

the same time the inclined walls of the flask will act in the same way as the inclined faces filled within a suitable .locity to the sand, the

to direct the sand against the several patterns anda-ssist 1n the compacting ofthe sand around the patterns. After the airhas'been expelled through the several openings some of the sand may protrude through the same, either through the bottomplate or through the openings in the patterns, and in such case, when the plate is removed, the sand may be smoothed off, or, if desired, ,the plate may be arranged to have a sliding movement, so as to smooth offsuch protuberances, Thepatterns may also be arranged. to be turned slightly in the mold-cavities so formed and.

smooth off an y roughness from pro'tuberances arising from such cause.

InFig. i I have illustrated a different manner of projecting the bulk of sand into the flask, this forming the subject-matter of a separate application of evendate herewith, Serial No. 412,860. In such case the sand is which in the drawings illustrated has a swinging motion to impart the necessary vereservoir being arranged to swing in a circular course and to be brought above the flask, so that the sand contained within the reservoir may be projected therefrom directly into the flask. The mo tion is imparted tothc reservoir 7:, bymeans of the coiled spring 70', surrounding the shaft k on the standard 1& and connected to. the swinging'arm 7.1 carrying the reservoir. This is shown simply to illustrate anothermethod of imparting motion to the sand, and in such case the air has the same free escape from the flask as that above'described.

In Fig. 5 I have illustrated the application of thein'vention to the making of cores. It is of course desirable that the outer walls of the core-box m shall be solid or imperforate, so as to form perfect outer walls to the core, and to provide for the escape of air I form perforations o in the base-plate 01, closing the lower end of the core-box, and for suchpurpose I may form rather large openings, covering the same with wire-gauze, so as to prevent the escape of sand. In'said' Fig. 5 I have illustrated-a piston 19 for projecting the sand from the sand-holder and generating the necessary force to cause the'sand to enter and pack withint 1e cavity of the core-box.

" By my inventon I am enabled to overcome the particular difliculty in forming-perfect molds by causing a bulk or body of sand to I enter the flask with suiflcient velocity to pack receiving cavity, so

itself therein by providing a free. and perfect escape for the air contained within the sandform merchantablemolds'by such method. It will be understood that I do. not confine myself to any particular location for the airoutlets, as they may be arranged in many feature being to provide the full and free escape of airfrom he flask when a body of sand sufficicnt to fill the'same,,.e t e 'r's the sand-receiving cavity.

holder or reservoir 70,.

that it is practicable to- No specific claim is made in this application-to the mechanism illustrated in Fig. 40f

the drawings further than the general claims of this application cover the same, as the mechanism shown-in that figure formsthe subject-matter of a separate application of even'date herewith, Serial No. 412,860.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The herein-described method of forming sand molds, consisting-in setting abulk 'or body'of sand sufficient to fill the flask in I11Q' 'tion, and causing it after motion is imparted to it to enter the sand-receiving cavity with sufficient velocity to pack therein, and at the same timeproviding free escape of the air from suchcavity to permit the sandto pack evenly and solidly therein, substantially as set forth.

2. The herein-described method of formingsand molds, consistingin positively moving a bulk or body of sand contained within a holder by applying pressure thereto, and so projecting the body or bulk of sand first from such holder and then into the flask, substantially as and for the purposes set forth.

3. The herein-described method of forming sand molds, consisting in positively moving a body or bulk of sand by applying pressure thereto at a point ,away from the empty flask, and guiding it in its course to the flask and so projecting the body or bulk of sand into the flask, substantially asset forth. v

4. The combination of a sand-holder for holding a body or bulk of sand, means'for applyingpressure t0 and projecting the body of sand in bulk from the holder, and a flask in line with but out of contact with the holder having perforations at or near, the base there- :of, substantially as set forth. 5. The combinationof a sand-holder for in line with the holder, andaguideway between the holder and flask, but out of contact with the flask, substantially asset forth. r

6. The combination of a sand-holder for holding a body or bulk of sand, means for projecting the body of sand in bulk from the sand-holder, a flask in' line with the holder having perforations at or near the base thereof, and'a guideway between the holder and flask, but out of contact with the flask, snbstantially' as set forth.

7. In apparatus for forming sand molds, the combination with a flask, of a sand-holder away from but in line with the flask, said sandholder having an inclosedspace above the sand to receive fluid n nder pressure to proj out the sand from the holder, substantially as and for the .pnrposesset forth.

'8. In apparatus for forming sand holds, the combination with a flask having a pattern extending 'up into the same, extendingnp within'th flask, and provided with a; fac'e" =o, rfacesnnelrned toward the pate holding a body or bulk of sand, means for projecting the. body of sand in bulk from the sand-holder, a flask of a projection tern, to direct the sand fed tothe flask against the pattern, substantially as and for the purposes set forth.

9. In apparatus for forming sand molds, the combination with a flask having inwardly-inclined walls, of patterns extending up within the same, and projections extending up within the flask provided with faces inclined toward the patterns, saidinclined flask walls and faces acting to direct the sand fed to the flask against the patterns, substantially as and for the purposes set forth.

10. In apparatus for forming. sand molds, the combination of a flask, a sand-holder for holding a body or bulk of sand away from .but in line with said flask, and a base-plate closing the lower end of said flask and having air-escape openings extending through said plate, substantially asset forth.

11. In apparatus for forming sand molds,

a flask having a base-plate closing the lower end thereof, and a pattern extending up within the flask, and having openings in the hollow base of the pattern and escape-outlets therefrom, substantially as and for the purposes set forth.

In testimony whereof I, the'said STEPHEN

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