US2948522A

US2948522A - Long lip crucible

Info

Publication number: US2948522A
Application number: US514544A
Authority: US
Inventors: George R Peters
Original assignee: ROSS TACONY CRUCIBLE CO
Current assignee: ROSS TACONY CRUCIBLE CO
Priority date: 1955-06-10
Filing date: 1955-06-10
Publication date: 1960-08-09
Anticipated expiration: 1977-08-09

Description

Aug. 9, 1960 G. R. PETERS LONG LIP CRUCIBLE Filed June 10, 1955 United States Patent 2,948,522 7 time LrP CRUCIBLE George R. Peters, Philadelphia, Pa., assignor to Ross- Tacony Crucible Co., Philadelphia, Pa., a corporation of Pennsylvania Filed June 10, 1955, Ser. No. 514,544

Claims. (Cl. 263-48) struct the long lip crucible of this invention of a refrac- 2 tory composition utilizing residual carbon bonding. Ex-

perience has shown that such refractory compositions are superior to other compositions in the manufacture and use of crucibles. Examples of carbon bonding compositions are those given in U.S. Patent No. 2,013,625, issued September 3, 1935, to K. E. Buck. Carbon bonding, 'which results from carbonization of ingredients such as tar and pitch, is highly resistant to weakening at high temperatures and to thermal shock. Consequently, crucibles made of compositions utilizing a residual carbon bonding stand up very well in use and have long life.

In the construction of any long lip crucible, it is necessary to form the long pouring lip separately from the body or pot of the crucible and then attach the lip to the body in the finished crucible. For many years, cement was employed as the sole means of attachment of the long lip to the body or pot. This practice had serious disadvantages but it was followed of necessity for lack of a. better method. Some of the disadvantages of this practice are the following.

occasioned by fastening the same to a furnacelining.

attachment of the lip at the place of manufacture introduces problems withrespect to shipping of the long [lip crucible as a whole and the consequent increase of risk of breakage in transit. 2

In my copending application Serial No. 344,570, filed March 25, 1953, now abandoned, there is disclosed and claimed a'method of constructing carbon bonded long lip crucibles by which the lip is eifectively integrated with the body or pot. 'I hat method eliminates the cemented joint \andove'rcomes the objections thereofwith respect to weakness of the joint but, since it involves integration of the long lip with the pot at the time of manufacture, it necessitates shipment of the crucible as a whole 'totheuser, which makes shipment diflicult and increases they risk of breakage in transit.

, The principal object of the present invention is to provide a long lip crucible construction which obviates all of the abovermentioned objections.

, .By this invention, there is provided a construction which is comparable in strength to the integrated struc- In some instances, the adhesi0n between the pot and the lip is not adequate to withstand strains imposed onit by the weight of the metal onthe lip during pouring and also strains on the lip ice ture produced by the method of my above-mentioned 'copendin-g application, but which is less expensive and enables shipment of the crucible with the long lip Idetached from the body or pot, the lip being easily attachable by the user.

In accordance with this invention, a long lip crucible is provided which comprises a crucible body or pot, a long pouring lip, and inter fitting portions on said body and said lip, one of said portions having an open-faced recess with an inwardly declined bottom surface and inwardly divergent side surfaces, and the other of said portions being slidably insertable from the top into said recess and having surfaces complemental to said recess surfaces. Preferably, the side surfaces of said recess are divergent both inwardly and upwardly, and the complemental side surfaces of the insertable portion are formed accordingly. Preferably also, the joint surfaces are coated as hereinafter described.

The invention may be fully understood by reference to the accompanying drawing, wherein Fig. 1 is a perspective view of a long lip crucible constructed according to the present invention; I

Fig. 2 is a plan view of the --interfitting portions of the pot and the long lip;

Fig. 3 is a perspective View of the lip attachment portion of the crucible body or pot, without the lip attached thereto;

Fig. 4 is a perspective view. of the detached long lip showing the attachment portion thereof; and

Fig. 5 is a sectional view taken along line 55 of Fig. 1.

In the construction of a long lip crucible according to this invention, the body or pot may be formed by molding of the material in soft plastic state and by building up the lip-attachment portion of the pot by means of suitable forming and tamping tools. The long lip may be formed in a simple press or mold having the desired shape of the lip, the material being placed therein in soft plastic state. Following the formation of the pot and the long lip with the material in plastic state, each is subjected to the usual treatment to efiect curing and finishing. Where the pot and the long lip are formed of a refractory mixture utilizing residual carbon bonding,

attachment portion 11, and a long lip 12 having an attachment end portion 13. As may be clearly seen in Figs. 3 and 5, portion 11 of the pot is a thickened wall portion at the upper part of the pot, and this portion has an outwardly facing recess 14, preferably of substantial width and depth, extending downward from the. top

thereof. By substantial is meant large enough to acoommodate the meeting end of the lip, said lip having a trough of a size adequate to handlev the charge of the crucible and having side walls at least as thick as the walls of the crucible at points where the crucible wall is not thickened. The recess has an inwardly declined bottom surface 15, and it has side surfaces 16 and '17 which are divergent bot-h inwardly and upwardly, Behind the recess is a residual wall portion 14a continuous with the inner Wall of pot 10 but thinner by the depth of the recess 14 than thickened wall portion 11. At the top of the pot and behind recess -14, a recess 18 in residual wall portion 14a is provided which constitutes an exit for molten material during pouring.

The long lip 12 is generally of trough form to. convey molten material leaving the pot by way of exit --18.

The attachment portion *13of the lip is-of'wi'dth and depth to fit tightly in recess 14, and has a bottom surface 19 declined toward the entrance end of the lip, and also has side surfaces'20 and 21 which are divergent both upwardly 'and towardsaid end. These surfaces are complementalrespectively-to the surfaces 15 to 17 'of 'recess14.

Prior to attachment of the lip to the pot, a refractory coating is preferably applied to the interfitting surfaces. A suitable coatingis a-mixture of 75% calcined powdered Kyanite and 25% fire clay. This coating acts as a drying agent and also retardsexuding of the glaze from the end portion 13 of the lip downwardly into the recess 14 from the top thereof. The interlocking structure possesses great strength, and makes the crucible as a whole as strong as if the lip actually were integrated with the pot. In fact, tests have shown that the interlocking structure is actually the strongest part of the crucible.

In addition to great strength of the juncture between the long lip and the pot, the construction provided by this invention enables shipment of the crucible with the long lip detached from the pot. As previously indicated, this simplifies shipping and lessens the risk of breakage in transit. The long lip is so easily attachable -to the pot that'anyone can perform the attaching operation. Thus, the lip is easily attachable to the pot at the place of use.

A further advantage of this construction is that the pot may be inserted in a cold furnace without the lip attached thereto, and then the lip may be attached to the pot.

A further important advantage of this construction is that it affords a tight joint between the pot and the long lip, so that no leakage can take place at the joint.

By way of'specific example of the preferred form of this invention, in one physical embodiment the pot has an outside diameter of 27", a height of 35", and a wall thickness of 1%". The thickened wall portion has a thickness of approximately 4" and the outwardly facing recess is approximately 1 /2" deep. The lip has a length of 14%". The interfitting recess and entrance end of the lip are approximately 6" high, 7" wide at the bottom, and 9" wide at the top.

While a preferred embodiment of the invention has been illustrated and described, the invention is not limited thereto but contemplates such modifications and other embodiments as may occur to those skilled in the art.

I claim:

1. A long lip crucible, comprising a crucible body or pot of refractory material having a thickened wall portion at the upper part thereof, said portion having an outwardly facing recess leaving a residual wall portion, said recess extending downward from the top thereof and inwardly to said residual wall portion, said recess having an essentially planar, inwardly declined bottom surface and having essentially planar, inwardly divergent side surfaces, said pl anar surfaces meeting in corners at angles of at least 90, and a long pouring lip of refractory material having an entrance end portion dimensioned to fit tightly in said recess with the end of the lip tightly against the residual wall portion, said end port-ion having an essentially planar bottom surface declined toward said end and having essentially planar side surfaces which are divergent toward said end, said surfaces of the lip being complemental to said surfaces of said recess for interlocking non-twistable engagement of said end portion'of the lip with said wall portion by insertion of said end portion. downwardly into said recessfr'om the top thereof. 7 V a '2. A long lip crucible, comprising a crucible body or i pot of refractory material having a thickened wall portion at the upper part thereof, said portion having an outwardly facing recess leaving a residual wall portion, said recess extending downward from the top thereof and inwardly to said residual wall portion, said recess having an essentially planar, inwardlydeclined bottom surface and having essentially planar, side surfaces which are divergent both inwardly and upwardly, said planar surfaces .meeting in-corners at angles of at'least and a long pouring lip of refractory material having an entrance end portion dh'nensioned to fit tightly in said'recess with the end of the lip tightly against the residual wall portion, said end portion having an essentially planar bottom surface declinedtoward said endandhaving essentially planar side surfaces which are divergent both upwardly and toward said end, said surfaces of the lip being complemental to said surfaces of said recess for interlocking, non-twistable engagement of said end portion of the lip with said wall portion by insertion of said end portion downwardly into said recess from the top thereof.

3. A long lip crucible, comprising a crucible body or pot of refractory material having a thickened wall portion at the upper part thereof, said portion having an outwardly facing recess of substantial width and depth leaving a residual wall portion, said recess extending downward from the top thereof and inwardly to said residual wall portion, said recess having an essentially planar inwardly declined bottom surface and having essentially planar, inwardly divergent side surfaces, said planar surfaces meeting in corners at angles of at least 90, and a long pouring lip of refractory material having an entrance end portion dimensioned to fit tightly in said recess with the end of the lip tightly against the residual wall portion, said end portion having an essentially planar bottom surface declined toward said end and having essentially planar side surfaces which are divergent toward said end, said surfaces of the lip being complemental to said surfaces of said recess for interlocking, non-twistable engagement of said end portion of the lip with said wall portion by insertion of said end portion downwardly int-osaid recess from the top thereof.

4. A long lip crucible, comprising a crucible body or pot of refractory material having a thickened wall portion at the upper part thereof, said portion having an outwardly facing recess of substantial width and depth leaving a residual wall portion, said recess extending downward from the top thereof and inwardly to said residual wall portion, said recess having an essentially planar, inwardly declined bottom surface and having essentially planar side surfaces which are divergent both inwardly and upwardly, said planar surfaces meeting in corners at angles of at least 90, and a long pouring lip of refractory material having an entrance end portion dimensioned to fit tightly in said recess with'the end of the lip tightly against the residual wallportion, said end portion having an essentially planar bottom surface declined toward said end and having essentially planar side surfaces which are divergent both upwardly and toward said end,'said surfaces of the lip being complemental to saidsurfaces of said recess for interlocking, 'non twistable engagement of said end portion of the lip with saidwall portion by insertion of said end portion'downwardly into said recess from the top thereof.

5. A long lip crucible, comprising a crucible body or pot of refractory material having a thickened wall portion at the upper part thereof, said portion having an outwardly facing recess leaving a residual wall portion, said recess extending downward from the top thereof and inwardly to said residual wall portion, said recess providing an essentially planar bottom ledge and havin said recess with the end of the lip tight against the References Cited in the file of this patent Wall, said end portion having an essentially planar bottom surface adapted to rest on the bottom ledge of the re- 2 UNITED STATES PATENTS cess and having essentially planar side surfaces which are 191,000 Campbell May 22, 1877 divergent toward said end, said surfaces of the lip being 5 540,292 Altmeyer June 4, 1895 complemental to said surfaces of said recess for inter- 1,673,115 Hauman June 12, 1928 locking non-twistable engagement of said end portion 2,195,523 South Apr. 2, 1940 of the lip With said wall portions by insertion of said 2,670,108 Skogstad et al.' 'Feb. 23, 1954 end portion downwardly into said recess from the top 2,793,021 Courtney May 21, 1957 thereof. 10 2,801,839 Lemmer Aug. 6, 1957