US593267A - Apparatus for forming sand molds - Google Patents

Description

(No Model.)

S. J. ADAMS.

APPARATUS FOR FORMING SAND MOLDS.

No. 593,267. Patented Nov. 9,1897.

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. UNITED STATES STEPHEN JARVIS ADAMS, OF

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PITTSBURG, PENNSYLVANIA.

APPARATUS FOR FORMING SAND MOLDS.

SPECIFICATION forming part of Letters Patent No. 593,267, dated November 9, 1897.

Application filed November 28, 1891 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 invented a new and useful Improvement in 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 the making of sand molds and cores, its object being to provide a means for packing the sand within the flask or core-box in such a way as to obtain an even packing thereof and at the same time to overcome the necessity of packing by hand or by mechanical packing or jarring means. The principal difficulty in bringing sand down to place within a core-box or around deep patterns is to pack within or around the same by means of the ordinary packing-tools in such a way as to cause the sand to be evenly packed, the ordinary tools or rammers packing the sand in layers, so that soft spots are formed in the molds or cores, into which the metal may press, or the same are packed too solidly, so that the metal will not lie against the same and will blow. Some rapid power means for forming these core-boxes and molds is very desirable, and the object of my invention is to provide the same.

It consists, generally stated, in an apparatus for forming molds comprising a flask, (which includes a core-b071,) means for applying fluid-pressure directly to the upper surface of the sand, and openings at the base of the flask to permit escape of the fluid under pressure.

To enable those skilled in the art to practice my invention, I will describe the same more fully, referring to the accompanying drawings, in which- Figure 1 is a vertical section of the apparatus for forming cores according to my invention, showing the same filled prior to the formation of the core. Fig. 2 is a like view showing the core completed. Fig. 3 shows the apparatus in its preferable form, and Fig. 4 is a like view illustrating the application of my invention to the'formation of molds Within flasks. 7

Like letters indicate like parts in each view.

As the invention is especially applicable to the formation of cores, I have illustrated the Serial No. M2359. (No model.)

same more particularly in connection therewith.

The core-box a maybe of any desired shape and is open at the lower end, its lower end, however,bein g closed by a suitable perforated plate or wire-netting, forming a perforated base-piece b, which is held in place by the ring 0, such perforated base-piece allowing the free escape of air from the lower end of the sand-receiving cavity of the core-box, but confining the sand therein. The ring 0 may be secured in place by any suitable means. At the upper end of the core-box I prefer to form an annular flange by means of which the core-box is connected to the sand holder or reservoir (1, the core-box having an annular flange e and the sand-holder the like flange f, and these two flanges fitting against each other and being connected by hooks gor other suitable means, so as to connect the sandholder and core-box securely together and form a practically tight joint between them, the joint being packed by a rubber or like gasket, if necessary. The sand-holder d is also open at the top and'sand is fed to it and to the core-box a through any suitable chute, the lower end of which is shown at h. The upper end of the sand-holder may be subsequently closed by a cap it, which cap is held in place by set-screws or may be closed by other suitable means, so forming a practically air-tight chamber in the upper end of the sand-holder and preventing escape of air at the upper end thereof. Connected to this sand-reservoir is the air-pressure pipe Z, which leads from any suitable air reservoir or pump to the upper end of the sand-holder cl and which is controlled by the valve m.

I prefer to form the walls of the reservoir or sand-holder d downwardly flaring,as shown in Fig. 3, so as to overcome friction between the sand and its holder as the sand is freed from contact with the walls when the pressure is applied. If it spreads, space for that purpose is provided without causing the sand to pack firmly against the sides of the reservoir.

In practicing my invention with the apparatus above described the core-box (I, having the perforated base-piece 6 extending across its lower-end, as shown in Figs. 1 and 2, is secured to the sand-holder (Z. By means of the chute h a suitable quantity of sand is fed to said sand-holder and. the top thereof is their closed by the cap 70. The operator then opens the valve m to permit the entrance of the air under pressure above the body of sand in the reservoir d, a pressure of several pounds being employed. It is to be understood that any suitable fluid-pressure may beemployed for the purpose, either air, steam, or gas, superheated steamserving the purpose very well, or an explosive mixture of gas and air may be introduced and subsequently exploded. The air or other fluid by pressing upon the surface of the body of sand serves to force the same downwardly intothe corebox, while at the same time the pressure exerted permeates the entire mass, and as the only escape is through the perforated base of the core-box the particles of sand are forced downwardly one against the other, and the air which was contained between the particles of sand when the loose sand was introduced into the core-box and reservoir is forced fromthesame and caused to escape through the perforated base, the packing-pressure being regulated according to the fluid-pressure exerted. It is found that not only is the sand forced downwardly from the reservoir into the core-box, but it is evenly packed throughout the core-box, an evenly-packed core be in g then obtained which is free from any soft spots and from which all .the air is expelled through the perforated base, so that all liability of the formation of air pockets or recesses in the core is overcome. As soon as the core is complete, which can be determined byexperience according to the proper pressureto be exerted, the air is cut off from the reservoir, the core-box separated therefrom, and any extra sand which -might not have been packed within the reservoir is struck off or removed from-thetopof the core if it adheres thereto, and the core can then be removed from the box in the usual way, the core-box again-secured in place, and the'oporation repeated.

In Fig. at I have illustrated the invention in connection with the formation of molds and havealso illustrated it where the air is compressedin a cylinder or pump arranged above the flask. The flask at is closed by the pattern-plate 19, carrying the patterns 19', said plate having perforations formed therein, as

at 19 through which the air ispermitted toescape. Above the flask n is the reservoir 7, and sand is fed to the flask 'n and reservoir 7' in any suitable way, the reservoir being of sufficient size to hold allthe sand necessary to properly form the mold within the flask. Above the reservoir 1 is the pump or cylinder 8, in which is mounted the piston s,which can be operated-in any suitable way through the piston-rod s spring-pressure, weights, or a suitable engine being connected to such pistonrodto exert the necessary force. The cylinder 8 is preferably made stationary and the flask and reservoir filled through any suitable chute adjacent to thesame and then.

brought underthe cylinder and rigidly secured throughout. The. spring, weight, or other power means are properly regulated to exert the pressure necessary to compact the sand within the flask and the operator causes the piston s to descend, when it forces the body of air between the piston and the sand against the upper surface of the sand and by pressure on the particles thereof forces the same downwardly into the flask, properly compacting the sand throughout the same and expelling the air through the perforated basepiece or pattern-plate of the flask, so completin g the mold. The reservoir and flask can then be disengaged from the cylinder 5 and the reservoir removed from the flask, the pattern-plate and patterns withdrawn, and the cores inserted within the mold so formed, so completing the mold.

It is to be understood that by the terms sand-holder or reservoir I include-any means of holding the. necessary sand to beforced by fluid-pressure into the core-boxerflask, and in case such results can be accomplished by the utilization of the upper partof or an extensionoftheflask or core-box such is included within the invention.

, WVhat I claim. as my invention, and desire to secure byLetters Patent; is-

1. An apparatus for forming sand molds, comprising a flask, means for applying fluidpressure directly tothe upper surface of the sand, and openings at the base of theflask, substantially as set forth.

2. In apparatus for forming sand molds, the combination of a flask having openings at or near the base of its sand-receivingcavity, asand holder communicating directly with the flask and means for applying fluid-pressure directly to the upper surface of the sand so as to act upon the sand and force it into the flask, substantially as set forth.

3. In apparatus for forming sand molds. the combination of a flask having openings at or near the base of its sand-receivingcavity, a sand-holder communicating directly with the flask and valve-controlled means leading from a suitable pressure apparatus for applysubstantially as and for the purposes set forth.

In testimony whereof I, the said STEPHEN JARVIS ADAMS, have hereunto set my hand.

STEPHEN JARVIS ADAMS.

Witnesses:

JAMES L'KAY, J. N. GooxE.

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