US2007993A - Method of producing lugged pottery - Google Patents

Description

July 16, 1935. G. B. ZAHNISER, JR, ET AL 2,007,993

METHOD 0F PRODUCING LUGG'ED POTTERY Filed Sept. 14, 1934 Patented July 16, 1935 METHOD OF PRODUCING LUGGED POTTERY George B. Zahniser, Jr., and James M. Smith, Jr., New Castle, Pa.

Application September 14, 1934, Serial No. 743,956

, 3 Claims. (01. 25-156) In the manufacture of pottery receptacles having lugs, handles or the like, it has been customary toproduce the body of the pottery receptacle according to one of several well known 5 practices, to produce the lug, handle or the like as aseparate article, and, while there is still sufficient moisture in the two parts thus produced, to afiixthe lug'or the like to the body of the receptacle. The lugged receptacle is then fired, after which it maybe finished as by decorating, glazing, etc., all of which operations are well understood in the art.

This invention relatesparticularly to the manner' of producing and applying'to the preformed 5 body of the pottery receptacle the lug, handle 'or the like. An object of the invention is to reduce the amount of hand operations required in the application of these parts to the preformed bodies ofthe pottery receptacles; and to' thus make it possible to produce more uniform articles at less cost.

The improvement is illustrated in the accompanying drawing in which Fig. 1 is a view-in elevation of the preformed body of a cup;

Fig. 1a is a similar view ofa slightly modified form of preformed body;

Fig. 2 illustrates the step in the process according to which a lug mold is applied against the preformed body of the receptacle;

Fig. 3 is a detail view of halves;

Fig. 4 is a View in elevation of a cup produced in accordance with our invention;

Fig. 5 is a detail plan view showing the juncture between the handle and body of the cup;

Figs. 6, 7 and 8 illustrate the prior art practice in accordance with which a preformed handle such as shown in Fig. 6 is cut to the proper shape, as shown in Fig. 7, by the workman and applied to the cup as shown in Fig. 8.

The drawing illustrates the improvement as applied to the production of cups; but it will become apparent in the course of the ensuing description that the change in the manufacture of cups set forth in detail is applicable likewise to pottery receptacles in general which are to be provided with lugs, handles or the like. In the description, the term lug will, for the sake of simplicity, be employed as a general term of definition applying to a handle or similar part.

No change is contemplated in the manner of producing the body 0 of the pottery receptacle. It is customary in the manufacture of china cups, for instance, to form this body portion 0 from a one of the mold mixture of plastic clay, silica and feldspar. The desired shape of cup may be obtained by a molding or pressing operation. Quite commonly the body is given a true and finished configuration by turning, as is Well known in this art. Ashas been above mentioned, it is within the contemplation of the. invention that the body bepreformed in any suitable manner; and in fact the same may be slip cast. i

The lugs heretofore have commonly been produced as separate articles, generally by slip casting. For instance, a slip having practicallythe same composition as the body of the cup, except for the increase in the water content, is cast. in a plaster of Paris mold to provide a handle it such as shown in Fig. 6. But a slight additional amount of water is required to render the com position thus fluid when a small addition, say 1%, of sodium silicate is made to the composition. The plaster of Paris moldacts towithdraw the slight amount of additional water; and as the fluidity of the composition depends upon this slight excess of water, the casting is soon firm enough to be handled. The cast handles are then trimmed or cut by the workman using an;

arcuate blade, the handles being cut to'fit the rounded side of the cup body as illustrated in Fig. 7. Skill and precision are required in thus trimming the blank to the correct shape h, and this is a source of high labor costs in the manufacture of these articles.

In accordance with our improved practice, a lug mold m is applied against the preformed body, as illustrated in Fig. 2, and the lug. is slip cast so as to unite with the body by pouring the slip into the mold 711.. The detail view, Fig. 3, of one-half of this mold shows the same provided with a surface 9 shaped to lie snugly against the side of the cup. This surface merges with the adjacent side wall of the mold cavity l0; and as the slip penetrates to fill the entire mold cavity, the lug in the finished productmerges with the body 0. A core I l forms the oval opening in the handle if this is the part which is tobe applied to the body. The slip enters through a pouring opening 12. Dowels l3 or the like may be employed for causing the two mold halves to accurately register.

In order to give suflicient pressure to make the impression clear, the pipe p may be used for pouring this slip so as to increase the static head. After the plaster of Paris mold m has absorbed sufiicient water to harden the lug or handle, the mold m is removed, and the cast lug or handle smoothed off at the point where the pouring decorations and/or the glazing, if applied to the opening [2 leaves a rough projection. It will be noted that this, the least finished portion of the casting, is on a lower and less conspicuous portion of the handle when the same is cast on a cup in the inverted position. There is no inherent reason why the lug should not be cast against the cup when in upright position instead of inverted position, but we prefer the inverted manner shown.

It will be noted from Fig. 3 that the mold cavity 10 opens against the side of the body 0, so that when the slip is poured into the mold, the cast lug is in the course of this operation united with the preformed receptacle. It may be found desirable in certain cases to provide the body of the receptacle during the forming of the same,.

with an indentation to improve the adherence of the lug to the body. Such a preformed body with an indentation M is illustrated in Fig. 1a. When assembling the mold m with the body 0, the opening of the mold cavity is brought into registry with this indentation; and accordingly in casting the lug the fluid slip fills the indentation, thus uniting the lug and body. lhe indentation is, of course, not visible in the com pleted article. The latter, as shown in Fig. 4 and in greater detail in Fig. 5. has a more finished appearancethan the product in which the handle is shaped by hand, as illustrated in Figs. 6, 7 and 8. From Fig. it will be noted that the cast lug merges into the body of the article in a way which cannot be readily duplicated, even by skilled workmen, when the lug h is trimmed to the shape It and then applied as a separate article to the body 0. v

After the mg or lugs have been applied to the receptacle, the same is fired in the usual manner. This improvement is not concerned with this portion of the usual manufacturing procedure, Moreover, the finishing, such as the fired article, can be performed in accordance with usual practice.

It will be apparent from theabove description that the invention eliminates a troublesome hand-operation in the production of lugged pottery articles. The new procedure is dependable,

more expeditious, and results in reducing the labor costs in the manufacture of these articles. Moreover, the product has a pleasing appearance, and the elimination of the human element makes for greater uniformity in the shape and. appearance of the finished product.

While we have illustrated and described our improved method more particularly in connection with the production of cups, it is clear that this is merely illustrative of how the invention may be applied generally to lugged pottery articles; and, therefore, it will be understood that our invention is not limited to the precise embodiment illustrated but may be otherwise embodied and practiced within the scope of the following claims.

We claim:

1. In a method of manufacturing lugged pottery receptacles, the steps consisting of preforming the body of the pottery receptacle, applying a lug mold against the preformed receptacle in such fashion as to bring the cavity opening into registry with the place on the receptacle determined upon for the lug, slip casting a lug, handle, or the like in said mold to unite with the preformed receptacle, and firing the lugged receptacle.

2. In a method of manufacturing lugged pottery receptacles, the steps consisting of preforming the body of the pottery receptacle, providing in registry with the place on the receptacle determined upon for the lug a mold cavity of the desired conformation, slip casting therein a lug, handle or the like, and firing the lugged receptacle.

3. In a method of manufacturing lugged pottery receptacles, the steps consisting of preforming the body of the pottery receptacle with an indentation where the lug is to be joined thereto, applying a lug mold against the preformed receptacle with the mold cavity opening in registry with said indentation, slip casting a lug, handle, or the like in said mold against the preformed receptacle uniting therewith, and firing the lugged receptacle.

GEORGE B. ZAHNISER, JR. JAMES M. SMITH, JR.

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