US1843175A

US1843175A - Refractory article

Info

Publication number: US1843175A
Application number: US388917A
Authority: US
Inventors: David B Sears
Original assignee: Corning Glass Works
Current assignee: Corning Glass Works
Priority date: 1929-08-28
Filing date: 1929-08-28
Publication date: 1932-02-02
Anticipated expiration: 1949-02-02

Description

Feb. 2 1932. D B SEARS 1,843,175

REFRACTORY ARTICLE Filed Aug. 28, 1929 INVENTOR BY 17514:! 5. Sears NEYS Patented Feb. 2, 1932 UNITED STATES PATENT OFFICE DAVID B. SEARS, OF CORNING, NEW YORK, ASSIGNOR TO CORNING GLASS WOB KS, OI GORNIN G, NEW YORK, A. CORPORATION OF NEW YORK REFRACTORY ARTICLE Application filed August 28, 1929. Serial No. 388,917.

This invention relates to improvements in refractory articles and more particularly to refractory needles such as are commonly employed in glass feeders.

5 Refractory needles to which this invention relates are suspended from one end of a rocking beam directly over the orifice of a forehearth and are alternately projected and retracted relative to the orifice so as to inter- 1 mittently extrude a gob of molten glass. Inasmuch as the lower end of the needle is submerged in the molten glass and its upper end protrudes beyond the top of the forehearth,

there is a wide diflference in temperature between the two ends of the needle and hence, when such needles are formed in one piece, strain is created within them which causes breakage and necessitates frequent replacements. To overcome this, it has been the m practice to build upthe needles from a series of relatively short hollow cylindrical sections which are threaded on a metallic rod, the .upper end of which is attached to the rocking o beam while the lower end is threaded to receive a nut which forms a stop'to prevent the sections from sliding off. In order to protect the lower end of the rod and the nut from the corrosive action of the glass and to protect the glass from contamination by the metal, it has been the practice to countersink the nut into the end of the lowermost cylindrical section and then pack the opening with clay. This has not always proven satisfactory owing to the fact that the texture of the packing rarely corresponds to that of the needle so that uneven expansion takes place and breakage is apt to occur. Moreover, the tight packing of the clay around the metal .parts does not allow for expansion of the 4 metal so that breakage is very apt to take place due to the difi'erences in the expansion coeflicients of the metallic and clay parts.

The object of the pres nt invention is to prevent breakage of a built up refractoryneedle which is caused by the expansion and contraction of the metallic parts.

Another object is to procure uniformity of the texture of the clay in the needle tip of a built up needle.

A further object is to completely enclose the metallic needle parts with a refractory of uniform texture so as to protect the gla from contamination through contact witli them.

The above and other objects ma be attained by the use of my invention w ich embodies among its features a needle tip havmg a chamber near its lower end in which an apertured plate is loosely fitted, said tip also having a longitudinal bore extending from the chamber throu h its upper end, a tie rod extending throug the bore and anchoring means on the lowerend of the rod for engaging the plate and anchoring the rod in the needle tip.

In the drawings:

Fig. 1 is a sectional view through aforehearth showing a needle suspended therein, the latter being constructed in accordance with this invention;

Fig. 2 is an enlar ed fragmentary sectional view of the nee e;

Fig. 3-is a transverse sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 2; 1

Fig. 5 is a perspective view of the metallic plate used in the needle tip; and

Fig. 6 is a perspective view of the anchor and a fragment of the tie rod.

Referring to the drawings in detail, a glass melting furnace 10 is provided with the usual forehearth 11 having a glass discharge 01'1- fice 12. A cover block 14 rests upon the upper edges of the forehearth to confine the heat generated by fires playing over the surface of molten glass 16 and is provlded with an opening 17 which aligns with the orifice 12. A rocking beam 18 is plvotally supported at 19 above the forehearth and one end of this beam is connected for oscillating movement to the usual feeder mechanism (not shown), while its opposite end is disposed over the opening 17. A needle designated generally 20 is suspended from the end of the beam 18 opposite that which is connected to the feeder mechanism, and extends downwardly through the opening 17 into the forehearth, its lower end being submerged beneath the level of the glass 16.

In its present form the needle 20 consists of a plurality of cylindrical sections 21 which are provided with longitudinal bores 22. Each of these sections is formed at its upper end with a tapered boss 23 which is adapted to fit into the tapered recess 24 formed in the bottom of the next adjacent section. In this manner proper alignment of one section with the other to form a complete needle unit is preserved.

The lowermost needle section designated by the numeral 25, like the sections 21, is formed with an upwardly extending boss 26 which is fitted in the recess 24 of the section immediately above it, but instead of being provided throughout its length with a longitudinal opening, it is formed with a chamber 27 and a transversely rectangular longitudinal opening 28 which communicates with the chamber and extends through the upper end of the needle section. A plate 29 is loosely fitted within the chamber and is provided with a slot 30 which corresponds in size and shape to the cross section of the opening 28. The under side of the plate is provided with aligning recesses 31 which communicate with the slot and form a groove for the reception of the anchoring member to be more fully hereinafter described. The plate is provided with depending" legs 32 which hold it in spaced relation to the bottom of the chamber. In order to hold the cylindrical sections in proper relation and provide an attached means by which the needle may be secured to the rocking beam, there is provided a metaL lic tie rod 33 which carries at its lower end an anchoring member 34.

In assembling the needle, the anchoring member 34 is introduced into the rectangular opening in the lowermost needle section 25, passed through the slot 30 and turned so that the shoulders on it engage in the recess 31. The other cylindrical sections are slipped over that portion of the-tie rodwhich projects beyond the upper'end of the tip section 25 so that their bosses 23 are receivedin the fr'actory sectionsconstructed as above described may be assembled in the same needle by using tie rods of proper length.

In some cases it may be found desirable to use a needle having diiferent characteristics at different places throughout its length, as

for instance, a refractory which is highly rcare broken need be removed and others may be readily substituted so as to effect economies in operation.

In the production of the needle tip; that is, that section containing the metallic plate, I mold the green clay about a core so as to form a rectangular opening leading from the chamberlongitudinally through the top of the section. I then place the metallic plate in position and surround it with a collar of combustible material such as cardboard. A cover of combustible material is then used to close the open end of the collar whereupon additional clay is then packed around the hollow core thus formed and moldedi'into the proper shape. The clay is then placed in kilns and burned to the desired temperature which is sufliciently high to cause the card board core to be consumed leaving only the metallic plate loosely fitted It is obvious that other methods of forming the chamber and introducingthe plate into it may be resorted to though I have found in the chamber.

.occur, only those sections of the needle which through experiment that the method. de-

scribed is satisfactory.

While in the foregoing there has been shown and described the preferred embodi-,

ment of my invention, it is to be understood that minor changes in the details of-cons.ruction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of my invention as claimed.

I claim:

1. A needle for glass feeders comprising a plurality of refractory sections, a tie rod extending through said sections, an anchor at one end of the tie rod, and means loosely fittedin one of the, refractory sections for cooperation with the anchor in holding the sections on the tie rod. 1

2. A needle for glass feeders comprising a plurality of refractory'section's, a tie rod extending through said sections, a metallic plate loosely fitted in one of said sections, and means on one end of the tie rod for engaging the plate and holding the sections in place.

3. A needle for glass feeders comprising a plurality of refractory sections, a tie rod extending through said sections, an anchor at one end of the tie rod, one of the sections being formed with a chamber, and a slotted plate loosely fitted in the chamber for engagement by the anchor whereby the sections are held against movement along the tie rod in one direction.

4. A needle tip including a refractory body formed with a chamber and having an openin g entering one end and communicating with the chamber, a slotted plate loosely fitted within the chamber, and means to maintain the plate adjacent to one end wall of the chamber to facilitate the introduction of an anchoring member beneath the plate.

DAVID B. SEARS.