US2574878A - Sagger pin - Google Patents

Description

'Nov- 13, 1951 A. w. LIVERSAGE SAGGER PIN Filed April 23, 1948 INVENTOR l rt TV. Livers age ATTORNEYS Patented Nov. 13,1951

UNITED STATES Arsrrr OFFICE SAGGER PIN Application April 23, 1948, Serial No. 22,742

3 Claims. 1

It is the object of this invention to provide sagger pins which may be employed to support ware during the glost fire without marring the glaze, either of the piece supported by the pin or of the piece beneath. 'It is also the object of this invention to provide a foot-supporting sagger pin which does not require a coating to prevent fusion of the foot of the ware to the sagger pm.

It has been customary in the art to support glazed ware during the glost fire by means of refractory sagger pins which engage the were beneath the rim. Such pins are triangular in cross-section, the apex of the end of the pin "contacting the undersurface of'the rim of the ware; three such pins are used. The :fault of this customary manner of supporting Ware during the glost fire is that, after the were has been fired and cooled, the apex of the end of the sagger pin has penetrated the glaze to the ceramic body of the ware, the glaze thereby firmly uniting the pin to the ware. To remove the sagger pins from the ware, it must be broken away by fracturing the pin adjacent the glaze or by breaking the glaze uniting the pin and the Ware. If the pin is fractured, a relatively large rough nub may be left united to the Ware; this nub can be removed only by grinding it away. In order to prevent such large nubs from being formed, it has been proposed to provide fracture lines adjacent the apex of the pin; such fracture lines, when they work, only insure a small nub, rather than a large one, being left in the glaze. In any event, rough, unsightly scars are left.

To eliminate the scars left by sagger pins which support the ware from the rim, as described above, it has recently been the practice to lengthen and invert the pin so that the foot of ware to be fired would rest on the base of the triangular pin. contact between the foot and the pin, the area of the contact surface being such that, during the glost fire, the weight of the ware would not deform the foot where it rests on the pin.- To prevent the ceramic body of the ware from fusing to the pin as well as to prevent the molten glaze from running during the fire and thereby uniting the foot of the ware to the base of the triangular pin, the dry, unfire'd glaze is wiped from the foot of the ware and the flat surface of the pin, adjacent the location of probable contact with. the foot, is coated with an anti-sticking compound. This compound is comprised of a fine refractory powder, such as powdered flint, and a vehicle, such as varnish, which volatilizes dur- Thus, there would be surface ing the glost fire. Such glaze as would otherwise melt and run from the ware adjacent the foot onto the pin to adhere the pin to the foot will be absorbed by the powdered fiint. The flint also, of course, separates the pin from the body of the ware, preventing fusion; without the separating flint, fusion of the pin to the ware, even .if unglazed, will occur at the temperatures of the glost fire and efforts to break such a bond between the fused pin and ware will be most like ly to break the foot of the ware.

The above outlined practice satisfactorily eliminates sagger pin scars, but, unfortunately, frequently produces far more serious damage.

7 Due to volatilization of the binder or vehicle of the anti-sticking compound during the glost fire, the infusible refractory powder simply rests on the fiat surface of the pins while the glaze isin a soft, molten condition. The slightest jarring of the sagger during the fire and during cooling will, of course, shake the refractory powder off the flat surface of the pin onto the soft glaze on the upper surface of the ware beneath, thereby spoiling that lower piece of ware. Further, great care has to be exercised in applying the anti-sticking compound so that only the fiat upper surface of the pin is coated; if the compound is carelessly applied to the side of the pin, the flint in the compound will be released and .fall on the ware beneath as soon as the .binder or vehicle volatilizes.

I have found that the foregoing difficulties may be simply and inexpensively eliminated by a proper configuration of a surface of the vsagger pin so that it may support the foot of ware to be fired without requiring an anti-sticking compound. Sagger pin scars are thereby eliminated as is thespoiling of ware beneath. No anti-sticking compound is required, the labor of applying such compound is eliminated, and the inspection of pins so coated is likewise eliminated.

I Other and further objects and advantages of this invention will be apparent from the following specification, claims, and drawings in which:

Fig. 1 is a vertical cross-section, showing a sagger employing my pins and supporting wars to be fired.

Fig. 2 is a horizontal cross-section taken on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged detail showing the manner in which the foot of ware (shown in section) rests on my pins.

Fig. 4 is an enlarged cross-section of a preferred embodiment of one of my pins, taken "along the line 4-4 of Fig. 3.

Fig. 5 is a perspective view of the pin shown in cross-section in Fig. 4.

As shown in Fig. 1, the frame of the sagger in which my pins may be employed may be of standard construction and is preferably comprised of a base spider l having, at the end of the spider arms, suitable mortises H in which the tenons 13 of three sagger posts l2 are remova-bly mounted. The sagger posts I 2, at equal distances above the base, are provided with radially inwardly directed Sockets [4 having a triangular cross-section adapted to receive my sagger pins 20. The sagger frame is locked in its assembled form by means of a top spider l5 having mortises I6 to receive the upper tenons ll of the sagger posts I2.

It is to be noted that when the sagger posts l2 are assembled, the triangular sockets are so positioned that the base of the triangle will be horizontal and uppermost. With sagger pins 20 fitted in the sockets M, as shown in Figs. 1 and 2, ware 30, coated with the green, unfired glaze except on the bottom of the foot 3|, is loaded in the sagger as shown in Fig. 1, and is ready for firing. The ware, before loading, is coated with green glaze in any suitable manner, as in an automatic glazing machine, and, then the glaze is wiped from the foot 3|. After firing and cooling the ware, the sagger is unloaded by simply lifting the ware from the pins 20. The pins are not united to the ware and no scars are produced in the glaze of the fired ware.

All of the foregoing result is obtained by the configuration of the sagger pins 20, as shown in detail in Figs. 3, 4, and 5 of the drawings. These pins are formed by extruding a suitable refractory body through an extrusion orifice to provide a pin having a general triangular crosssection but with parallel longitudinal ridges 21,

as shown in Figs. 4 and 5. The apices of the ridges 2| lie in a common plane and are preferably as sharp as the refractory material of the ex,- truded pin will permit. The extruded refractory pins are cut to the desired length, fired, and are then ready for use in the saggers. The composition of the refractory body may be varied to meet the requirement of the ware to be fired, that is, the body of the pin should remain relatively rigid and non-adherent to the ceramic body of the ware at the temperature at which the ware is to be fired. Thus, a refractory body satisfactory for pins to support ware given a soft, low-melting glaze would not be satisfactory for ware given a high glost fire, but pins for ware to be fired at a relatively high temperature will, of course, be satisfactory for ware to be fired at a relatively lower temperature.

The area of the cross-section of the pinswill, of course, depend upon the weight of the ware to be fired and the strength of. the refractory body at the firing temperature. The number of ridges may likewise be varied, three being shown since this number is satisfactory for most dinnerware. If heavier ware is to be fired, the cross-sectional areas of the pin may have to be increased and the number of ridges or like ware supporting elements may also have to be increased to provide a sufficient number of points of contact with the foot of the ware to support the ware during firing without deformation.

As shown in Fig. 3, with the pins 20 held in the posts l2 so that the ridged surface is uppermost, and the length of the pin such that the pin will extend radially inwardly to a diameter less than the diameter of the foot of the ware, the ware 30 will rest, by its foot 3|, on the pin ridges 2!. The glaze 32 having been wiped from the bottom of the foot 3|, the apices of the pin ridges 21 provide a plurality of closely adjacent point contacts with the ceramic body 33, distributing the load on the foot 3| so that no deformation occurs during firing. Although the refractory pin will adhere slightly to the body 33 at the temperature at which the fusible glaze is fired, no union of the pin to the ware will occur during the glost fire; also, a slight amount of glaze may run from the Ware down to the ridges 2| during the glost fire. Nevertheless, the actual areas of the points of contact with the ridges 2| are so slight that at the worst a slight sticking, rather than a union, is produced and the ware is easily removed from the pins.

It is to be understood that this invention is not to be limited to the particular embodiment disclosed but may be varied by those skilled in the art, the limits of this invention being set forth in the appended claims.

What is claimed is:

1. A sagger pin for supporting green ware during a glost fire comprising an elongated refractory pin having a substantially constant triangular cross-section throughout its length, a plurality of integral spaced longitudinal ridges on one face thereof, said ridges being of the same height and having triangular cross-sections to provide sharp apices, whereby ware supported by said pin will contact said ridges and said ridges will provide an effective area of support and prevent said foot from uniting with said pins during a glost fire.

2. Apparatus for supporting dishware during the glost fire comprising a sagger, a set of substantially horizontal ware-supporting refractory pins for a piece of dishware to be fired in said sagger, said set consisting of at least three pins supported at their outer ends by said sagger and extending, at substantially equal angles to each other, radially inwardly and terminating at points short of the center of said sagger, each of said pins having a substantially constant cross-section throughout its length and being provided with a plurality of closely spaced fine longitudinally extending ridges having apices extending upwardly from the upper surface of the pin and terminating in a common plane above the body of the pin, whereby Ware supported by said pins will contact said ridges and said ridges will provide an effective area of support and prevent said foot from uniting with said pins during a glost fire.

3. Apparatus as defined in claim 2 in which the cross-section of said pins, when supported in said sagger, is an inverted triangle and said ridges are on the base of said triangle.

ALBERT W. LIVERSAGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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