US219130A - Improvement in devices for cooling castings - Google Patents

Description

UNITED STATES PATENT OEEIoE.

HARRYWIARD, W'ILLIAM R. BULLOCK, AND LEVI W. HALL, OF SYRACUSE,

NEW YORK.

IMPROVEMENT IN DEVICS FOR COOLING CASTINGS.

Specification forming part of Letters Patent N o. 219,130, dated September 2, 1879; application filed April :25, 1879.

To all whom it 'may conce/m:

Be it known that We, HARRYWIARD, WIL- LIAM R. BULLooK, and LEvI W. HALL, of Syracuse, New York, have invented certain Devices for Cooling Iron Castings for Mold- Boards of Plows and other purposes, of which the following is a specification.

Several devices have been essayed for cooling chilled cast-iron mold-boards, car-wheels, Ste., such as a heated plate placed upon the surface of the casting, or the free admission of external air thereto; and such castings have been buried inmsand or combustible matter, none of which devices are our invention, and fail, so far as our experience has proved, to effect the object of preventing undue strain, breakage, or other injury to the casting or drawing the chill in the process of casting.

Castings made on the principles heretofore patented We have found to more or less shrink and warp and crack in cooling, rendering them liable to break afterward.

The most approved methods that we have known and heretofore employed were to cover the chilled surface of the casting, after removing the chill, `with heated sand, or with some carbonaceous or other solid matter of analogous character tending to increase the heat. We have found the following practical difficulties in their use: It is impossible to thereby equalize and control the heat, cooling all parts alike; and when combustible matter is employed it is ignited, and not only in-` creases the heat most at those points where the casting is the hottest, but somewhat draws the chill unequally at the surface, where it should be most perfect, and the result is an unequal contraction, and consequently a strain or breakage and loss of castings, by any of these methods.

By our device We attain the cooling of castings without breakage or strain from unequal cooling or injury to the chilled surface there of, giving the castings greater strength, and rendering the process of casting more certain, cheap, and convenient.

The following is a description of our device, referring to the accompanying drawings, in which- V Figure 1 is a vertical longitudinal section through the mold on the line x y of Fig. 4, showing the parts in place just after the casting is poured. Fig. 2 is a similar section of the mold, on the line o w of Fig. 4, after the chill is removed, and With the cover' in place upon the mold, forming the close air-chamber v over the casting 5 Fig. 3, plan of the chill b. Fig. 4 is a plan View of the mold with the casting in it.

The upper flask, a, Fig. 1, contain-ing the sand mold, is placed upon the lower one or chill, b, and the casting is poured in the usual way. As soon as the metal has set the asks are turned over and the chill b removed. The cover c is then placed over the mold and casting, covering the whole exposed surface thereot' and fitting down closely all around outside the casting, with a projecting rimy ou the cover, that sinks into the sand of the mold, or otherwise makes a tight joint, and forms an air-chamber over the casting, inclosing a stratum of highly-heated air over the Whole surface of the casting, which, by its mobility Within the chamber, produces currents and keeps all the parts of the casting equally hot, abstracting heat from the hottest parts and distributing it to the cooler parts, so as to bring and keep all parts to an equal temperature, Iand thus prevent unequal contraction" and strain in any part in cooling. y

To retard the cooling to any desired degree, the cover can be heated more or less before being put on, and heated air may be intro duced, if required.

` To further assist in retaining the heat, the cover c can be covered with a layer of non; conducting material, a rim, r, being formed on it to hold the same.

To inspect the casting in theprocess of cool` ing, one or more apertures, s, may be made in the cover c and covered with mica.

By the above-described device the cooling process is governed and the heat more equally distributed over the whole surface ofthe cast ing than in any other way with which we are acquainted, and more cheaply and conveniently.

We are aware that the casting of car-wheels has been essayed in which the chillfor the rim has been removed and the coping suri rounding it has been replaced, leaving the space occupied by the chill to be occupied by air inclosed Within it for retarding1 the cooling of that part, While the center of the Wheel is exposed to currents of air to equalize the cooling of the entire wheel by removing the center portion of tbe mold for that purpose, which is not our invention.

Having thus `fully described our improvements incooling,` castings, We claim- The combination of :i flask containing 2t mold, and yet hot-chiiled casting remaining in the mold, and e cover covering one surface of the casting, being the chilled surface, and surrounding the exterior edge of the casting, secludingg` it practically from the outer air und forming an air-chamber, whereby a, body of confined hot stir is secured against the cesting, substantially as and for the purposes described.

' HARRY WIARD.

WILLIAM R. BULLOCK. LEVI W. HALL. Witnesses:

J. J. GREENOUGH, J. P. MUNRO.

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