US683486A - Method of coating and drying molds. - Google Patents

Description

UNITED STATES rPATENT OFFICE.

VWILLIAM J. PATTERSON AND ALOYSIUS WIOKLAND, OF PITTSBURG, PENN- SYLVANIA, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE AMERICAN CASTING MACHINE CO., OF NEW JERSEY.

METHOD OF COATING AND DRYING MOLDS.

SPECIFICATION forming part of Letters Patent No. 683,486, dated October 1, 1901.

Application filed February 24, 1899.

To LZZ whom t may concern:

Be it known that we, WILLIAM J. PATTER- soN and ALoYsIUs WICKLAND, residents of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Coating and Drying Molds; and we do hereby declare the following to be a full, clear, and exact description thereof.

Our invention relates to a method of drying and coating the interiors of molds in metal-casting apparatus, Where a number of molds are mounted on a traveling carrier7 the molds being poured at one end of the apparatus and discharged at the opposite end, such as set forth and described in Letters Patent of the United States No. 583,424., granted to A. M. Acklin May 25, 1897. In said Letters Patent there is set forth and claimed a method of casting pig metal, consisting in pouring the metal into molds partially submerged in water, passing said molds in a horizontal course through said water in the partially-submerged state, and then passing said molds in a horizontal course through said water in a completely-submerged state. The molds are mounted on an endless carrier or chain, and after they have discharged their contents they pass down and return to point of pouring in an inverted position. These molds after the pigs have been discharged are in a wetted condition, owing to their passage through the tank or the spraying of the molds after leaving the tank, and therefore When formed of thin Wrought metal the wrought iron or steel molds remain Wet or damp in their course back to the receiving end of the machine to be again filled with pig metal, and if the highly-molten pig metal strikes the molds When Wet the metal is liable to sputter, wasting the same, while the metal may strike some of the workmen and burn them. The thin Wrought-metal molds did not carry sufficient heat to dry the molds in their return course. In such form of casting apparatus more or less trouble has been eX- perienced by reason of the pigs adhering and sticking to the molds when solidified, and various attempts have been made to avoid this difficulty, but with unsatisfactory results.

Serial No. 706,730. (No specimens.)

Devices for spraying the molds with water and mixtures of dierent refractory materials have been employed in various forms to insure the free delivery of the pigs from the molds, and coatings of lime, clay, or similar refractory materials have been used for this purpose, and a mechanical device for imparting a blow to the molds or pigs just prior to their discharge has also been contrived. These methods of treatment are all 6o more or less objectionable, as they do not always Work satisfactorily. The use of clay is particularly objectionable on pigs which are to be used in the basic open-hearth process or to be melted in a cupola prior to the Bessemer process, and the use of lime is also to be avoided on pigs which are to be used in the acid process, all of which will be readily understood by those skilled in the art of making steel. Further than this, the 7o use of washes made of lime, clay, or other ordinary refractorymaterials has the effect of materially shortening the life of the molds and is particularly severe in its action upon the bearing and wearing portions of an endless-carrier machine, as these mineral refractories have the effect of abrading the working parts of the apparatus very rapidly. We practically overcome the above objections by applying a fresh coating of carbona- 8o ceous material to the molds just prior to the introduction therein of the molten metal, and in addition to preserving the working faces of the molds from destruction by the molten metal and allowing the pigs to be readily discharged therefrom we find that this material is free from all of the above-stated objections, and from its nature, instead of abrading the working parts of the machine, it acts as a lubricator, thus preventing friction and loss of 9o power, and thereby preserves the working surfaces from destruction. This carbonaceous coating is also free from the objections heretofore stated with respect to the use of clay or lime on pigs which are to be used for steel-making, as the carbonaceous matter is comparatively neutral and has no eect upon the lining of the furnaces or cupolas, nor does it aifect the slag which is formed in the melting or refiningprocess.

It is found expedient roo in such form of casting apparatus to have the molds formed with lips which overlap each other, so that when the metal is poured said overlapping lips will prevent the metal from falling in between the molds. The metal is liable to adhere to the molds, and especially if it drops on these lips it is liable to adhere thereto, so that this metal Which has fallen on said lips Will form a 'fin-like portion on the pig, Which will be broken off when the pig is discharged into the receptacle at the discharge end of the apparatus, or if a portion still adheres it will be Worn off or broken up in the handling of the pig afterward. This metal is Wasted and is a matter of great loss.

The object of our invention is to provide for the drying of the molds Where they become Wet in the course of cooling the metal cast therein and to provide a coating for the surfaces thereof to prevent the metal adhering to the bodies or overlapping lips in the manner before referred to.

To these ends the invention consists, generally stated, in pouring the metal in a controllable stream into such endless connected series of traveling molds and moving the Whole continuously at such speed that they will be uniformly tilled and cooling the metal cast Within the molds, preferably by Watercooling, and automatically delivering the pigs therefrom and then carrying the inverted molds over fuel-burning apparatus, so as to thoroughly dry the molds in their course back to the receiving end and prevent the flying of the metal above referred to and at the same time to form a deposit of soot upon the faces of the molds as they return to be filled with the molten metal, the thin film of soot forming a surfacing which will prevent the metal from adhering to either the bodies or the lips of the molds. It also consists in certain other improvements to be hereinafter more fully set forth.

To enable others skilled-in the art to make and use our invention, We Will describe the same more fully, referring to the accompanying drawings, in which- Figure l is a side elevation of a portion of a suitable casting apparatus to which our invention is applicable. Fig. 2 is a crosssection of same on line 2 2, Fig. l. Fig. 3 is an enlarged view of a portion of the traveling mold-carrier. Water-tank.

Like letters of reference indicate like parts in each View. l

While We have above referred to our invention as applicable to the method of casting pig metal contained in said Patent No. 583,424 and will describe it in connection with said method in the present application, yet We do not Wish to limit its application in any sense to the method of casting set forth in said patent.

In the drawings, Fig. l illustrates a portion of a suitable metalcasting apparatus, in which the letter a designates the frame or the portion thereof adjacentto the pouring end Fig. 4 is a cross section of the of the apparatus. The tank h is supported by the frame a, and Within said tank is the track c, upon which the Wheels dof the endless chain e travel. The track f is the returntrack, supported by the frame ct, and -the Wheels d travel on said track When the molds return in theirinverted position to the pourin g-point. The endless chain or mold-carrier e may be of any suitable construction, and as it forms no part of our present invention a detailed description is not deemed necessary. The moldsg are secured to the endless chain c, said molds having the overlapping lips g', Which prevent the spilling of the metal in pouring between the molds and at the same time allow for the elongation of the endless chain, due to wear, Without creating a gap loe tween the molds. The chain e is mounted on suitable sprocket-wheels arranged at each end of the frame, the sprockets at the pouring end only being shown. The tracks h may be used to carry the ladle conveying the molten metal from the blast-furnace, While il represents the pouring-trough.

Beneath the frame a are the pits 7c, With tracks m arranged transversely of the frame a. Upon these tracks'are the trucks n, supporting the fuel-burning apparatus, such as the pots or furnaces 0, of any suitable construction. These furnaces o are arranged at suitable intervals apart, and any number required for the purpose of our invention may be employed. The fire-chamber o is provided with the grate-bars o2, and o3 is the door for the admission of fuel. The furnaces o when in the position shown in Fig. 2 are directly under the frame a, and the molds g in their inverted position travel directly over said furnaces, so as to be heated and dried thereby and receive the coating of soot from the smoke rising from the furnaces. In order to direct the products of combustion into the molds, the conical hood p is provided.

In practicing the invention the metal is poured into the molds as they pass under the pouring-ladle. The molds are then carried through the cooling liquid of the tank, (not shoWn,) and when they arrive at the opposite end of the frame the pigs are discharged from said molds. The molds then return in an inverted position, as shown in Fig. l. The molds, which have previously passed through the Water of the tank or been Wet in other Ways in connection with the cooling of the metal therein, are thoroughly dried as they pass over the tops of the furnaces o, the heat from the same being directed into the inverted molds and quickly drying them, so that all liability of the metal being poured into Wet molds is overcome. For the purpose of smoking the molds any suitable smoke-producing fuel can be used which Will form a sooty greasy coating on the surface of the molds, and the fact that the molds are comparatively moist or damp when brought above the furnaces causes the soot to more easily deposit thereon and to adhere more firmly to IOO IIO

the lips and interiors of the molds. For this purpose bituminous coal may be employed and only enough air admitted to the furnaces to support a slow combustion, from which a heavy smoke discharge is obtained. Where oil or other gaseous or liquid fuel is used, the conditions are such as to cause imperfect combustion, generating smoke, While obtaining sufficient heat for the drying of the molds. Any carbonaceous fuel which when imperfectly consumed Will deposit the soot on the molds may of course be employed. Any suitable furnaces or burners may be used, and We do not Wish to limit ourselves in any manner to the particular form of apparatus for burning the fuel beneath the molds; Where the furnace is such as illustrated and employs solid fuel, when the apparatus is not in operation the furnace may be run to one side of the frame on the tracks m, so that undue heating of the molds when at a standstill is avoided.

In pouring the metal, as stated above, it is liable to drop on the overlapping lips g and adhere thereto, so that When the molds arrive at the point of discharge this thin portion is broken od by the fall of the pigs into the receptacle placed there to receive them or in the later handling of the pigs and is lost. The coating of the molds With soot, as above set forth, forms a smooth or greasy surface both in the interiors or bodies of the molds and upon these lips, and the metal instead of adhering to the lips slips back into the molds, so that no fins are formed. The coating further acts to protect the molds when the metal is poured.

No claim is made in this application for the apparatus herein described, as the same is embodied in a divisional application tiled September 8, 1899, Serial No. 729,810.

What We claim as our invention, and desire to secure by Letters Patent, is-

l. The herein-described method of casting pig metal, which consists in pouring the metal in a controllable stream into an endless connected series of traveling molds, cooling the metal Within said molds by contact With Water, delivering the pigs successively from said molds, and subjecting the inverted molds successively to heat while still Wet and during their return course to the receiving end of the machine and thereby drying the molds, substantially as set forth.

2. The herein-described method of casting pig metal, Which consists in pouring the metal in a controllable stream into an endless connected series of traveling molds, cooling the metal Within said molds by contact with Water, delivering the pigs successively from said molds, and carrying the inverted molds While still Wet over fuel-burning apparatus in their return course to the receiving end of the machine and thereby drying the molds, substantially as set forth.

3. The herein-described method of casting pig metal which consists in pouring the metal in a controllable stream into an endless connected series of traveling molds, cooling the metal when in said molds by contact With Water, delivering the pigs successively from said molds, and carrying the inverted molds While still Wet over heating and smoke-discharging means and thereby drying them and depositing soot upon the faces of the empty molds as they return to be filled with molten metal, substantially as set forth.

4. The herein-described method of casting pig metal which consists in pouring the metal in a controllable stream into an endless connected series of traveling molds, carrying the molds containing the metal down into a body of water and thereby cooling and wetting the molds, delivering the pigs successively from said molds, and carrying the inverted molds while still wet over heating and smoke-discharging means and thereby drying them and depositing soot upon the faces of the empty molds as they return to be filled With molten metal, substantially as set forth.

5. The herein-described method of casting pig metal, which consists in pouring the metal into an endless connected series of traveling molds, cooling the metal within said molds by contact with water, delivering the pigs from said molds, and then directing into the molds sooty carbonaceous material from a smoking fire of bituminous material whereby the molds are dried and a coating of sooty carbonaceous material is deposited on the mold-surfaces.

In testimony whereof We, the said WILLIAM IPATTERSON and ALoYsIUs WIOKLANnhaVe hereunto set our hands.

' WILLIAM J. PATTERSON. ALOYSIUS WICKLAND.

Witnesses:

W. S. HOCKING, H. R. RosE.

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