US3870273A

US3870273A - Self-inverting hot top casing

Info

Publication number: US3870273A
Application number: US146701A
Authority: US
Inventors: Joseph Perri
Original assignee: Aetna Business Credit Inc
Current assignee: Aetna Business Credit Inc
Priority date: 1971-05-25
Filing date: 1971-05-25
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

Abstract

The present disclosure is directed to a novel hot top casing and a method for relining this casing. Two pairs of turning trunnions are provided, one pair above and one below the casing center of gravity. When the lower trunnions are engaged by J-hooks and the casing raised, this permits the casing to rotate to its inverted position. The casing is lowered to a platform and relined. The Vhooks now engage the lower trunnions (which were originally the upper trunnions) and again raise the casing. The casing is permitted to rotate to its upright position where it can be lowered to an ingot mold for the subsequent pouring of steel.

Description

O United States Patent 1 1 1111 3,870,273

Perri Mar. 11, 1975 [54] SELF-INVERTING HOT TOP CASING 1.781.135 10/1970 Germany 294/73 227,547 2/1969 U.S.S.R..... 249/201 [75] Jseph Per", Corapolls, 1.370,620 7/l964 France 249/201 [73] Assignee: Aetna Business Credit, Inc., New

York, NY. Primary Examiner-Robert D. Baldwin [22] Filed, May 25 1971 Attorney, Agent, or Firm-Buell, Blenko and Ziesenheim [21] App]. N0.: 146,701

[57] ABSTRACT [52] US. Cl. 249/202, 294/73 51 rm. c1 1322a 7/10 The Presst dlsclosure d'rected novel hot toP 58 Field of Search 249/197-202 casing and a method refining this casmg- TWO 1%irs 249/106 [64/33 294/733 of turning trunnions are provided, one pair above and one below the casing center of gravity. When the [56] References Cited lower trunnions are engaged by J-hooks and the casing raised, this permits the casing to rotate to its inverted UNITED STATES PATENTS position. The casing is lowered to a platform and rel,804.204 5/1931 Churman et al. 249/201 1i The v now engage the lower trunnions gi "i (which were originally the upper trunnions) and again 7I69797 851939 fi f 6 X raise the casing. The casing is permitted to rotate to its upright position where it can be lowered to an ingot FOREIGN PATENTS OR APPLICATIONS mold for the subsequent pouring of steel.

149,544 4/l964 U.S S.R 249/201 566,759 12/1932 Germany 294/73 3 Clam, 16 Drawmg Flgures l I L- I I j PATENTEDHARI 1 I975 snwlarz INVENTOR JOSEPH pR/Q/ BY ATIO EY SELF-INVERTING I-IOT TOP CASING BACKGROUND OF THE INVENTION The present invention relates to the field of hot top casings for use in connection with ingot molds and more particularly to'an improved construction of hot top casings.

At present, most hot top casing used in the pouring of steel ingots are provided near the top with laterallyprojecting lifting lugs for engagement by crane hooks or by J-hook fixture hung from the crane hook. In this manner, the hot top can be raised, lowered and transported. Such hot tops are also generally provided with a pair of opposed laterally-projecting trunnions which are located at the casing center of gravity.

These casings are conventionally lined with insulating panels and have a refractory or insulating ring placed at the bottom of the casing and fastened to it by clips. Each hot top is designed to either rest upon the top of or slightly inside the ingot mold, and the steel is poured through such hot top easing into the mold to form the steel ingot. Once the ingot has solidified, the hot top casing is lifted by the crane books or J-hooks which engage the lifting lugs. This strips the hot top from the ingot sink head leaving the remains of the disintegrated liner and ring deposited thereon. The casing is then transported to a platform where it is lowered onto a special stand having saddles which receive and support the casing trunnions in such a manner that the casing can be rotated. The transporting hooks are further lowered and disengaged from the lifting lugs.

The casing is rotated 180 into its inverted position by manually exerting a force sufficient to overcome the friction between the turning trunnion and the supporting stand saddles. The casing is relined with new panels, and a new ring is affixed to the bottom of the casing. After relining is complete, the casing is manually rotated back into an upright position so that it can be lifted from the stand by the crane or .I-hooks and transported to the ingot mold.

This present technique has proven hazardous to the workers who manually invert the casing. Since the easing has been stripped from the mold shortly after the steel is poured, the casing is very hot; and the worker exposes himself to being seriously burned. Furthermore, there is considerable manual effort required to be expended by the worker, particularly with the larg-' er-sized casings, even though the turning trunnions are located at the center of gravity. Not only must the easing be made to rotate, it must be stopped by the worker in its inverted position so that the relining of the casing can take place. Following relining, the casing must be rotated again and once again stopped when it reaches the upright position.

From the standpoint of cost, special stands with turning saddles must be provided for each size of hot top casing used in the steel mill. These stands are costly both to build and maintain and require a considerable amount of floor space on the hot top relining platform.

SUMMARY OF THE INVENTION The present invention comprises a method for lining the central opening of a hot top casing without the need for special turning stand and without the need for manual effort to invert and reinvert the hot top casing. When the hot top casing is to be lined, it is lifted and then permitted to self-invert and is then lowered onto a floor or platform where the lining of the casing occurs. After the casing is lined, it is again raised and allowed to self-invert to its upright poisiton so that it can be lowered to the ingot mold for the subsequent pouring of steel. Novel hot top casings with speciallydesigned turning trunnions are also disclosed.

It is an object of the present invention to provide an improved hot top casing with insulating panels.

It is another object of the present invention to provide a hot top casing which eliminates the need for specially-designed turning stands and the manual rotation of the hot top casing when positioned on such stands.

It is a further object of the present invention to provide an improved process for lining hot top casing which provides increased safety for the worker and less cost to the mill.

Still another object of the present invention is to provide an improved hot top casing having turning trunnions which are specially disposed on the casing to facilitate the self-inverting process.

A still further object of the present invention is to provide a method for lining a hot top casing with insulating panels which is rapid in operation and permits the replacement of expended liners without exposing the worker to unwarranted health and safety hazards.

Other objects and advantages of the present invention will become apparent from a reading of the following description in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 1a show side elevations of a preferred embodiment of a hot top casing used in practicing the present invention;

FIGS. 2 and 2a show side elevations of another preferred embodiment of a hot top casing;

FIGS. 3 and 3a show side elevation and plan views of another preferred embodiment of a hot top casing;

FIGS. 4 and 4a show side elevation and plan views of another preferred embodiment of a hot top casing;

FIG. 5 shows a perspective view of a preferred embodiment of a hot top casing engaged by .I-hooks; and

FIGS. 6a 6g show in schematic form a sequence of easing orientations experienced in the practice of a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to the drawings and first to FIGS. 1 and 1a, a hot to p casing is depicted generally by the numeral 10. Casing 10 is shown as being formed with four sides and having two pairs of trunnions l2 and 14. The trunnions 12 are diametrically opposed to one another on opposite sides of the casting as are the trunnions 14. Both pairs of

trunnions

12 and 14 are aligned along the vertical center line 16 of the hot top casing. The center of gravity 18 of the casing 10 will fall approximately on this vertical center line 16. As shown in FIGS. 1 and la, the trunnions 12 are placed above the center of gravity 18 while the pair of trunnions 14 are placed below this center of gravity. Casing 10 is also shown as being provided with a pair of lifting lugs 20 disposed adjacent the top of the casing; such lugs 20, however, do not form any part of the present invention.

In FIGS. 2 and 2a, the casing 10 is shown as having its upper trunnions l2 and its lower trunnions l4 disposed on adjacent sides of the casing in contrast to FIG.

1 where they were disposed on the same sides. Again in FIG. 2, each trunnion of a pair is positioned diametrically opposite the other upon the casing. As shown in FIG. 2, trunnions 14 are located along the vertical center line 16 of the casing as are trunnions 12, as can be seen from FIG. 2a. Again, trunnions 12 are placed above the center of gravity 18 of the casing while the trunnions 14 are placed below the center of gravity.

Vertically aligned with the pair of trunnions 14 is a pair of horizontal extensions, projections or pads 22. Pads 22 are disposed above the center of gravity 18 to assist in the inverting of casing 10 as hereinafter described. Similarly, a pair of pads 24 are associated with trunnions 12, each pad 24 being vertically aligned with one of these trunnions. Each pad 24 is placed on the opposite side of the center of gravity from the trunnion 12.

FIGS. 3 and 4 show casings 10 similar in construction to those of FIGS. 1 and 2 but in which the trunnions have been horizontally displaced from the vertical center line to cause a designed imbalance in order to start rotation of the casing as described later. First with regard to FIGS. 3 and 3a showing side elevation and plan views, respectively, two pairs of trunnions l2 and 14 are again provided. Each trunnion 12 is aligned vertically with a trunnion 14, but both of these pairs of trunnions are horizontally offset from the vertical center line 16 of the casing. For example, as shown, the

trunnions

12 and 14 have all been displaced horizontally an equal amount to the left of the casing center line 16. Again, trunnions 12 are placed above the center of gravity 18 of the casing while the trunnions 14 are located below the center of gravity.

In FIGS. 4 and 4a, the upper trunnions l2 and the lower trunnions 14 are positioned on adjacent sides of the casings. Trunnions 14 are both offset an equal amount with respect to one vertical center line of casing 10 and are disposed below the center of gravity 18. As shown in the plan view of FIG. 4a, trunnions 12 are also both equally offset from the vertical center line of the casing, and as shown in FIG. 4 are placed above the center of gravity 18.

Note in both FIGS. 3 and 4 that the center of gravity is shifted slightly due to this offset of the

trunnions

12 and 14; obviously, however, this shift in the center of gravity is not as great as the offset of the trunnions l2 and 14, and the design imbalance is attained.

In FIG. there is shown a perspective view of a hot top casing of the type shown in FIGS. 1 and 1a, with lifting lugs 20 removed for purpose of illustration. Conventional panels or liners 30 are shown lining the inside surface of the hot top casing 10. Casing 10 is here shown as resting upon the top of an ingot mold 32, although it is to be understood that the casing 10 can be the type which partly resides within the mold opening during the pouring of steel. Upper and lower trunnions 12 and 14, respectively, are shown in FIG. 5; but their opposite numbers are hidden from view in this figure.

In practice of the method of lining a hot top casing, crane hooks can be employed to engage the trunnions of the hot top 10 although it is generally more convenient to employ the apparatus 34 shown. This apparatus is commonly termed .I-hooks and has two legs in the configuration of a J which are spaced apart with a span sufficient to engage a pair of opposed trunnions on the hot top casing 10. The J-hooks 34 also have a center eye member 36 adapted to be engaged by the stripper crane hook 38.

After the steel has been poured into the ingot mold 32 through the opening of hot top casing 10, the .I- hooks 34 are lowered by the stripper crane 38 to engage the pair' of lower trunnions 14 of casing. The stripper crane is now raised to strip the hot top casing away from the ingot sink head. A lateral force is created by the edge 40 of each leg of J-hooks 34 against an upper trunnion 12 as the casing is elevated, and this force begins to rotate the casing 10 off of dead center. With reference now to FIGS. 6a 6f, showing the crane 38 moving forward or to the right, casing 10 begins a clockwise direction of rotation (FIG. As shown in FIGS. 6b and 6c, this clockwise rotation continues because of the increased eccentricity of the center of gravity of the casing 10 with respect to the pivot points of trunnions 14. Rotation continues until, as shown in FIG. 6d, the casing 10 has become inverted. The trunnions 14 now form the upper trunnions, and the trunnions 12 form the lower trunnions. The casing is lowered onto a platform or floor depicted by the numeral 42. The .I-hooks 34 are now lowered further by the stripper crane 38 and withdrawn from engagement with the trunnions 14. The casing is now relined with panels, refractory or insulating ring, and retaining clamps to the extent called for by the particular hot top casing design being used.

To transfer the relined casing 10 from the platform back to an ingot mold 32, the J-hooks 34, which are now shown as oriented in the reversed direction, are lowered until they engage the lower trunnions 12. The crane hook 38 is now raised, causing a lateral force to be exerted against the upper trunnions 14 by the inside edge 40 of each leg of the .I-hooks 34. This force acting about the pivot point of lower trunnion 14 causes the casing 10 to begin to rotate and, as shown in FIG. 6f, such rotation is in a counterclockwise direction. This rotation continues until casing 10 is inverted to its upright position. Casing 10 can now be lowered onto the ingot mold 32, as shown in FIG. 6g. The .I-hooks are lowered and removed from engagement with the trunnions 12. The relined casing 10 is ready for the pouring of steel.

In the relining of a casing constructed according to FIG. 2, the steps are the same as described with respect to FIG. 1 above. Note, however, that the

pads

22 and 24 function as upper trunnions for inverting and reinverting the casing, respectively, in that each pair of pads provide surfaces forthe inside edge 40 of each leg of the .I-hooks 34 to bear against to provide the force necessary to move casing 10 off dead center and begin rotation. Thus, pad 22 comes into use during the inverting of the casing in order that it can be relined; and pad 24 comes into use for reinverting the casing once it has been relined.

In FIGS. 3 and 4, the turning trunnions 12 and 14 are, in each case, offset laterally from the casing center of gravity so that a built-in imbalance is provided with respect to the casing center of gravity 18. For example, with regard to FIG. 3, when .I-hooks engage lower trunnions 14 and the casing 10 is raised, a moment is created about turning trunnions 14 due to the lateral displacement of the center of gravity 18 from the pivot points of these trunnions. This moment will cause a clockwise rotation of the casing 10 until it becomes inverted. Once the casing 10 is relined, the .I-hooks will engage the trunnions 12, which are now the lower trunnions, to elevate the casing. Again the design imbalance creates a moment about trunnions 12 which permits the rotation of casing to begin without the application of any extraneous force. The rotation continues until casing 10 assumes its upright position.

Note that in FIG. 4 the placement of the two pairs of trunnions on adjacent sides clearly demonstrates how offsetting the trunnions from the casing center line obviates the need for pads or upper trunnions to ensure rotation of casing 10. During both the steps of inverting or reinverting the casing, the design imbalance acting about the pivotal trunnions causes the desired casing rotation without the need to apply any outside force to the casing, such as is applied by the faces 40 of the J- hooks in the embodiments of FIGS. 1 and 2.

Although the present invention has been described with respect to preferred embodiments thereof, it should now be obvious that modifications and alternatives can be introduced without departing from the spirit and scope of the invention as set forth herein and covered by the appended claims.

What is claimed is:

1. In a hot top casing having a central pouring opening therethrough and an external surface, the improvement comprising:

a. two independent pairs of lift trunnions extending from said external surface,

b. one of said pairs of trunnions being positioned above the center of gravity of said casing,

c. the other of said pair of trunnions being positioned below the center of gravity of said casing,

d. both of said pairs of trunnions being horizontally offset from the center of gravity of said casing to give said casing a designed weight imbalance so that said casing will rotate when elevated by the lower most pair of said two pairs of trunnions, whereby the casing is inverted automatically each time it is picked up by the lower most pair of said two pairs of lift trunnions.

2. A hot top casing as claimed in claim 1 wherein:

a. said two pairs of trunnions are in vertical alignment on said casing surface.

3. A hot top casing as claimed in claim 1 wherein:

a. said two pairs of trunnions are horizontally offset from one another on said casing surface, so as not to be in vertical alignment.

Claims

1. In a hot top casing having a central pouring opening therethrough and an external surface, the improvement comprising: a. two independent pairs of lift trunnions extending from said external surface, b. one of said pairs of trunnions being positioned above the center of gravity of said casing, c. the other of said pairs of trunnions being positioned below the center of gravity of said casing, d. both of said pairs of trunnions being horizontally offset from the center of gravity of said casing to give said casing a designed weight imbalance so that said casing will rotate when elevated by the lower most pair of said two pairs of trunnions, whereby the casing is inverted automatically each time it is picked up by the lower most pair of said two pairs of lift trunnions.

2. A hot top casing as claimed in claim 1 wherein: a. said two pairs of trunnions are in vertical alignment on said casing surface.