US122255A - Improvement in making steel castings - Google Patents

Description

(33) WHLLIAM KELLY.

Improvement inmaking Steel Castings.

N0. 122,255. Patented Dec. 26,1871.

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WILLIAM KELLY, OF LOUISVILLE, KENTUCKY.

IMPROVEMENT IN MAKING STEEL CASTINGS.

Specification forming part of Letters Patent No. 122,255, dated December 26, 187

SPECIFICATION.

To all whom it may concern:

Be it known that I, WILLIAM KELLY, of Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and useful Improvements in Process of Making Steel Castings; and I do hereby declare that the following is a full and exactdescription thereof, reference being had to the accompanying drawing making a part of this application.

' My invention consists in the process and apparatus for molding steel, by which the dificulties heretofore experienced of making sound castings are overcome, as will be hereinafterv more fully set forth.

In pouring fluid steel into a mold the intense heat contained in the same produces vaporization of small particles, and the inability of this vapor to escape produces small holes, or honeycombs77 as they are sometimes called, which of course render the casting more or less weak and otherwise objectionable. Many attempts `have been made to overcome this difficulty, but with ill success. The most important has `been the employment of copper molds, the great conducting power of the copper serving to convey the heat away so rapidly as to prevent the vaporization and consequent formation of honey-comb 5 but this cure brings with it-an objection in another direction, namely, that where the casting is at all intricate or has any inequalities 0f form varying materially from a smooth surface the l copper mold, being rigid and inflexible, the rapid cooling and contraction of the steel will cause it to crack, so that for very many forms of castings copper molds cannot be constructed so as to relieve the castings quick enough to prevent cracking; and, again, where the casting is designed to have thin edges, these thin vedges are liable .to be defective from wants or spaces in the mold not filled up with steel. The metallic mold is also objectionable on account of the difdculty of freeing the castings from the same. To remedy these objections is the object of my `invention; and to enable those skilled in the art to more fully understand the same I will proceed to describe the process and apparatus used by me, referring by letters to the accompanying drawing, in which- Figure l is a top view of a mold ready to re- Fig. 2 is a vertical cross-section at the line a: w, Fig. l; and Fig. 3 is an end view looking from the left at Fig. 1.

Similar letters indicate like parts in the several figures.

A is an iron frame or ask, intended to contain either dry or green molding-sand, though I prefer dry. B B indicate the molds for two plowpoints made therein. The lines C C are the out.

lines of the two cope-s or covers of copper, of a shape corresponding with' and adapted to fit over and close -the molds; and the heavy dotted lines of D D represent pieces of copper embedded in the sand, so as to act as a facing to thatthe point l of the ilask resting on the point 2 of the door-frame, and as soon as lled it is turned back to the position shown at Fig. 3 to cool. G is a clamping-bar for holding the copes7 or covers C C in place by means of two thumb or set screws, c c. The construction of this clamp-bar is clearly shown at Fig. 2. The end to the left is turned down at right angles, as seen at d, `and is slightly cut away, or shoulders formed thereon, at 3 to lock it with an open staple, e, one ofwhich is secured or cast upon either end of the iiask. Another end piece, f, independent of the bar G and similar to the one d, (except it is longer and is provided with a shoulder, y, arranged to overlap the end of G,) is secured in a like manner to the other end of the flask, and thus the bar Gr is held in place by the screws c c being forced down against the copes or covers C G, which they also hold in place. This end piece f I denominate the trigger, and its operation I will presently describe.

' seen at Fig. 3, so that when the trigger fis knocked off the fIask will drop down on the frame F, while the end of the copes remaining on the In pouring the iiuid steel the steps is slightly lifted up, allowing the thick side of the casting to be rst exposed to the action of the air. The flask is allowed tov remain thus for about ten minutes so as to cool off, when it can be opened and the castings removed.

I have found from experience that thin castings are less likely to crack when the ask is turned up in a vertical position for pouring and .then returned to a horizontal position for a definite space of time before opening the copes. The reason appears to be that the lines of contraction change With the changed positions of the flask.

In other Words, I have found it advisable and important to alter the position of the flask prior to final cooling.

Having described the apparatus, I will noW describe the process for molding steel castings.`

The mold in the sand having been designed, I

place at such points as experience will suggest` pieces'of copper to serve as conductors of heat, while the interposed sandthat is, that which is between the copper and thev casting-allows the contraction of the latter Without crac-king, thus embodying the important features of both a copper and a sand mold without the ill ei'ects exy perienced in each by itself. y

I am aware that pieces of iron have been placed in sand-molds Where iron castings are to be made for the purpose of chilling the casting, but the object of the. copper in my process is for an en` I entirely overcome by slightly displacingl the copper cope just sufficient to remove it from its original bed b y a sliding movement, thereby loosing it from the casting Without opening` the ask 5 and it may be entirely opened, as hereinbefore set forth.

I am familiar With the patent granted to F. F. Smith November 20, 1864, for castingploW-points, and do not wish to be understood as claiming anything containedtherein;l but Having described the apparatus and process, what I claim as new, and desire to secure by Letters Patent, is

1. The process herein described of preventing cracking, porosity, or other defects in steel castings by the employment of copper or its equivalent in a mold of sand, substantially asv herein set forth.

`the castings,A will be thrown forward and thusy free the casting from binding.

4. I also claim in the apparatus the combination and arrangement of the flask with the floorframe, the copes, the clamp-bar, set-screws, and trigger, all constructed substantially as described, for the purposes set forth.

Witness my hand and seal this 12th day of September, 1871.

WM. KELLY. [L. s.]i

Witnesses:

A. I. MOXHAM,

W. P. COLEMAN.

2. I also claim pouring duid steel into a mold

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