US45716A - Improved molder s sprue - Google Patents

Description

UNTTED STATES PATENT OFFICE.

MARTIN R. HO\VELL, OF ELIZABETHPORT, NEV JERSEY.

I'IVIPROVED MOLDERS SPRUE.

Spcciiicaton forming part oi' Letters Patent No, d 5,716, dated Jnnc 3, lSG.

To f/.ZZ 1u/tom it may concern,.-

Be it known that I, MARTIN It. HOWELL, of Elizabethport, in the count-y of Union and State otNew Jersey, have invented new and useful Improvements in Molders Sprues; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had` to the accompanying drawings, forming part of this specification, in whichn Figures 1, 2, 3, 4, 5, 6, and 7 are representations of sprues f'or use in casting, all constructed after my invention. Fig. S shows a transverse vertical section ot the sprue now used in the best foundries, and Fie. 9 shows a like section of a sprue in its earliest style.

Similar letters of reference indicate like parts.

This invention consists in certain improvements in the construction of sprues used by molders in their art, whereby the work is facilitated, better castings are made, and less metal is wasted than when the ordinary form of sprue is used.

In molding for stove and other castings gates are formed in the face sand for the admission of the metal to the mold. They are now generally made of wood, of either around form, like pins, or oblong. It madelike pins they are such as are represented in Fig. 7, page 89, of Overmans Molders and Founders Ioeket Guide,77 published in Philadelphia, in 1851, also in Fig. 15, page 78, and Fig. 17, page 82, and are made tapering in general outline, and after they are withdrawn from the sand the holes are eut out larger, bellunouthed shaped, at the top of t-he flask. lt' the gates are made oblong, they are made tapering on one side only, as shown in Fig. 910i' the aeeompanying drawings, and their ends have straight sides and angular edges or corners. The shape of the taper side has been of late years modified, as shown in Fig. S, where the taper is made upon aenrved lin e, and the oblong gate, or (as it is also called) the sprue,77 for some years has been of thet'orm shown in Fin. S-to wit., with one vertical side, one concave side, and with straight rectangular ends. Its thickness also at the line ai, and above and be low that line, is about as here represented, terminating at its bottom in an edge as thin as here shown.

This form of sp1-ue or gate has several disadvantages, some of which I will here enumerate.

First. Its straight and angular ends make it difficult for the molderto withdraw it from the sand without breaking the corners, and Whenever that occurs he is compelled to patch and smooth the fracture, so that in pouring7 the metal shall not carry any sand before it into the mold, and thereby make a defective casting. i

Second. The workman, when pouring the metal, approaches the sprue opposite the curved side. Vhen large plates are to be cast-such as stove-plates-sevcral gates are formed in the box. With sprues like the one shown in Fig. 8 it is evident that when they are set on opposite sides of the flask the molder must handle his ladle differently for different sides-that is, left-handed for one side and right-handed for the other side-to cause the metal to impinge upon the convex face of the spruc. This difficulty Occurs at each end of the flask, it two sets of sprues are formed in each end. It is also to be remarked that the metal must be poured into each sprue of the same mold or casting simultaneously and not successively, and therefore it is necessary and usual tohave a separate workman with a ladle of'metal at each separate sprue. Each alternate one of them must of course pour left-handed,7 and as very few workmen can handle the ladle expeditiously and efficiently in more than one way, constant inconvenience results therefrom. in the foundry and much bad work. Furthermore, as the niolder who prepares the work which has more than two sprues must ask the assistance ot' his fellow workman in pouring the metal therein, jealousics, which often arise among the men, continually impede the work.

Third. In the form ot' sprue shown in Figs. 8 and 9, any slag which may be poured with the metal is likely to be carried down before the metal into the mold. i

Fourth. The great body ot' metal. which is left in the sprue or gate in molding with forms such as are shown in Figs. 8 and t), and which are often thicker immediately above their bottom than the casing to be made, causes injury to the casting by reason that the metal therein, being thicker and in greater body, cools less rapidly, and the casting for a considerable distance about their line of Contact becomes burnt, in the technical language of the molding-shop.

In order to overcome these and other difliculties, I have invented a sprue or gate, the principle of which is illustrated in the examples shown by Figs. 1 to 7, both inclusive.

Fig. l is a side elevation and Fig. 3 an end elevation of a sprue with a straight lower edge, for plain work. Its ends are rounded for the purpose ot' enabling the melder to make a smooth sprue without the difficulty and hinderances which attend the making ot' sharp angles in moldinga Each side or face is also made concave, and the thickness of the sprue is reduced so as to be nearly of the same diameter in cross-section for a considerable distance from its lower edge or foot upward. It results from this construction that a right or left handed man can approach the iiask from any direction, as both i'aces of the sprue are curved alike. The sprue or gate, in the process of pouring, being kept full of the molten metal, and the sprue being for so considerable a distance above its foot of dimensions or of a diameter about equal to its foot, it follows that the slag which may escape from the ladle will iioat in the upper part of the sprue, Where the sudden enlargement of the diameter affords it room to float.

Fig. 2 is a Sprue constructed on thesaine principle, but having an edge or foot formed to suit the contour of the pattern from which the casting is to be made, Showing how an oblong sprue may be used for a casting of an irregular surface.

Fig. 4L shows a sprue also made on the same principle, with a break, a, in it, to enable me to use one sprue for separate castings in one ilask instead of a separate sprue for each casting. It is evident that the use of this form of sprue will save the labor of one workman in pouring the metal.

Figs. 5, 6, and 7 represent still another niodiiication, made on the same principle, in which provision is made for casting plates Whose eX- terior lines are curved. Fig. 5 shows this sprue from below; Fig. 6, an elevation, and Fig. 7 across-section, on the line y of Fig. 5.

Otherr :modifications may be made to suit the varying forms of the castings to be made, and the illustrationsin Figs. 2 and 5 will suf tice to show how this can be accomplished without departing from the principle of lny invention. v

A great saving is made in the work by the use ot" sprues of my construction, by reason of the small amount of metal left in the sprue after pouring oyer the amount left therein when the old styles are used, the difference in favor ot' my sprue being from two hundred (200) to three hundred (300) pounds to the ton of metal poured. The waste metal thus formed, called also the spruej7 is knocked off the casting when the flask is opened, and is wheeled to the cupola to be remelted. I am able to save, therefore, much ofthe labor and expense of remelting this large amount of waste metal.

I claim'as new and desire to secure by Letters Patent- A ii'loldingsprue constructed withconcave sides and curved ends, as above explained. as. a new article of manufacture.

M. It. HOWELL.

'Witnessesz M. M. LivINGsToN, l C. L. TorLirr.

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