US2063675A - Means for stripping ingots - Google Patents

Description

Dec. 8, 19 36.

0. HIVELY v MEANS FOR STRIPPING INGOTS Filed Jan. 7, 1935 s shed -sh ep 2 Dec. 8, 1936. o. HIVELY MEANS FOR STRIPPING INGOTS 3 Sheets-Sheet 3 Filed Jan. '7, 1935 d 8 & 5 g m. D m a f n L a? 1 1 d 5 m. QU 1 B Patented Dec. 8, 1936 MEANS FOR STRIPPING INGOTS Ossian Hively, Alliance, Ohio, assignor to The Morgan Engineering Company, Alliance, Ohio Application January 7, 1935, Scrial'No. 768

8 Claims.

-This invention relates to a method and means for stripping an ingot from a big-end-up mold and the primary purpose of the invention is to improve mold supporting means so that stripping may be accomplished by stripper cranes of known construction.

One company in the United States has bee for many years a leading manufacturer of stripper cranes and such cranes were originally designed to strip big-end-down molds which are still used very largely in the trade in casting ingots. With this type of mold, the stripper links engage the ears of the mold, while the stripper ram is inserted through the top of the mold, holding the ingot down on the stool-while the links pull the mold off the ingot. The mold is .then raised high enough to clear the ingot and is placed upon an empty car-standing ready to receive it, on a track next to and parallel to that on which the-stripped ingot stands.

The constant endeavor of the steel industry has been to reduce the amount of discard from the top of the ingot. This discardis due to pipes, blow-holes, segregations and crystallizations which take place in the metal in the ingot during the solidification of the liquid metal.

Various methods have been used to reduce the loss from discard, among which is the so-called hot top mold or the'big end up mold. The bigend-up mold, of course, cannot be stripped in .the same manner as has been done with the old type of mold for the reason that the ingot must be removed through the top of the mold instead of through the bottom opening.

One method of preventing undue loss in the ingot discard, has been to place a ring of refractory material, such as baked clay, surmounting the ingot mold. This non-conducting ring kept the-steel in a molten state so'that it cooled slowly toward the center of the ingot and thus increased the percentage of sound steel in the ingot. This type of ingot mold is stripped by :first breaking oil" the insulating ring, then grip- "ping'the protruding sink'head with crane tongs and-pulling the ingot out of the mold, while at the same time holding the mold down by means of apair of links resting on the top of the mold.

A further demand for clean steel, especially in such refined industries as the automotive plants, has of late increased the production of what is known in the trade as rimming steel which is so efiervescent in character when liquid, that it must be cast in 'flush top molds, which are also of the big-end-up type.

A purpose of this invention is to provide a means for stripping molds of this latter type by the use of already existing overhead travelling crane type of electric strippers, of which there are many in use representing an investment of many millions of dollars.

Another object is to use already cars.

Another purpose is to provide a means of stripping this type of molds, retaining the molds on the cars whilepouring the ingot and stripping same.

With the foregoing objects outlined and with other objects in View which will appear as the description proceeds, the invention consists in the novel features hereinafter describedin detail, illustrated in 'the accompanying drawings, and more particularly pointed-out in the appended claims.

In the drawings:

Fig. 1 is a vertical cross sectional viewof the improved stripping 1 stool with the mold in the position it occupieswhile the metal is being poured and showing a portion of the stripper mechanism "ready to stripthe ingot from 'the mold. V

Fig. '2-is a similar view of the' stoohmold and ingot after the ingot has been loosened from the mold. r

Fig. '3 is avertical sectional view of a portion of-a known type of stripper crane.

Figs. 4,5 and 6, are vertical sectional views respectively of modifications of the stool.

Referring to Figs. 1 to 3 inclusive, of the drawings, 3 designates the improved stripping stool designed to be carried ona conventionalingot "car'4. I'he stool forms a frame 5 and is pro- "vided'at its central portion with a rigidly connected, upstanding stem 6 forming a stripper rain on which the bottom of the mold is slidable; 'such ram being secured in position by any 'suitablemeanssuch as a nut 1. Bell crank 1e- -vers 8 :are positioned vertically on the frame aandimounted for swinging movement on hori- 'zontal trunnions 9 carried by the frame. Each lever has a projecting ear 10 for use in swinging the lower portions of the levers away from -theram 6. Each lever also has a step H and these steps normally support the mold l2 while "the ingot is being poured. Springs l3 on the frame,'extend into pockets [4 in the lower ends of the levers for yieldingly holding them in position to :support the mold, and keeper plates l5 act to hold the springs in place.

The stripper crane mechanism may be of conventional construction and include apertured existing ingot links I6 which swing on horizontal trunnions I6a. At II the crane stripper may be provided with an inverted cup or horseshoe-shaped member, and this cup will be forced downwardly simultaneously with the lifting of the link It by any suitable means, such as a double acting screw I8. A suitable type of crane stripper is shown in the patent to Bigler and Kloos 1,807,275, May 26, 1931.

In using such mechanism, the ingot I9 is cast while the mold is in the position shown in Fig. 1, and when it is desired to strip the ingot from the mold, the crane links I 6 are brought into engagement with the ears ID of the bell crank levers, and the member I1 is brought to bear on the top of the mold, whereupon the crane operator causes the double acting screw I8 to revolve in the proper direction so that an upward movement on the link I6 and a downward movement on the cup I! are simultaneously exerted. This pulls the steps II from beneath the mold and at the same time the latter is forced downwardly by the cup I1. During the downward movement of the mold, the latter is supported in its original position by the ram 6 and after such movement, the stool, mold and ingot will assume the positions shown in Fig. 2. The ingot can then be gripped at its upper end by means of crane tongs and lifted free of the mold.

To place the mold in its initial position to receive a subsequent pouring, the links I6 are brought into engagement with lugs 20 on the upper end of the mold and as the links-are moved upwardly they elevate the mold, until the springs I3 snap the steps I I underneath the mold again, whereupon the mold and other parts will be ready for the next pouring.

In the modification of the stool shown in Fig. 4, it will be observed that I have eliminated the spring and substituted interlocking bell cranks, although the general operation is the same as with the spring. This modification was designed to overcome any objection that might be raised as to having the springs in a locality where there is a great deal of heat. Referring to this modification, 3a designates a cup-shaped stool having a stationary ram 6a which projects upwardly from the central portion of the bottom of the stool for the purpose of supporting the ingot while the mold is moved downwardly. During the pouring operation, the mold is. supported by steps I Ia on a first pair of bell crank levers 8a pivotally mounted on trunnions 9a supported by the stool. These levers cooperate with a second pair of locking bell crank levers 8b pivoted on horizontal trunnions 9b supported by the stool. The arms I I b of the second levers act to limit the movement of the levers 8a while they are supporting the mold, and arms Illa of the upper levers form ears tobe :engaged by the links I6 of the] stripping mechanism shown in Fig. 1. Obviously when the links pull upwardly on the arms Ina, they release the levers Ba andallow the mold to move downwardly away from the ingot while the latter is supported by the ram 6a.

In case objection should be made to the dropping of the mold by the structures shown in Figs.

1 to 4 inclusive, from its normal or pouring position to the upper surface of the stool, I may employ stools of the type shown in Figs. 5 and 6.

In these embodiments the mold in pouring position rests on steps and the stripping is not accomplished by allowing the mold to drop, but is brought about by pushing the mold downwardly um" it rests on the stool; the springs in such case having suflicient strength to sustain the weight of the mold and ingot in the initial or normal position and also being susceptible of compression to allow the levers to be pushed away enough to permit the mold to pass by its lower position. However, during such movement, the springs through the levers exert a braking action on the mold which prevents it from dropping. In reference to the specific details of such stools, it will be noted in Fig. 5 that the cupshaped stool 3c is provided with ears Iflc designed to be engaged by the links I6 of the crane stripper, and the bell crank levers 8c are mounted on trunnions 90 within the stool. Each lever has a mold-supporting step II c on one arm and its other arm Mo engages a vertical coil spring I30 arranged within the stool. Of course, this stool also has a stationary ram 60.

Instead of employing bell crank levers, I may use single arm levers 8d as illustrated in Fig. 6. These levers are mounted at their upper ends on trunnions 9d supported by the stool and their lower ends are engaged by coil springs I3d which act to force the levers toward the stationary ram 6d.- Each lever has a mold-supporting step Nd and the stool has ears Ind to be engaged by the links I6.

With the forms of stools shown in Figs. 5 and 6, pressure on the mold, while it is supported by the steps, will cause the levers to recede while they are braked by the springs, and, of course, the stool can be lifted while the mold is being forced downwardly, although this is not absolutely necessary.

While I have disclosed what I now consider to be preferred embodiments of my apparatus and ways of practicing the method, it will be understood that changes may be made in the details disclosed without departing from the spirit of'the invention as expressed in the claims.

What I claim and desire to secure by Letters Patent is:

1. An ingot stripping stool of the character described comprising a frame having a top opening of sufiicient size to receive a conventional ingot mold, bellcranks journaled in the frame and having suspended arms provided with seats to support an ingot mold, means for holding the bellcranks in engagement with the mold, lugs on said bellcranks projecting from opposite sides of the frame and adapted to be engaged by crane links for swinging the bellcranks out of engagement with the mold, and a ram rigidly secured to the bottom portion of the stool and projecting upwardly in the frame to contact the lower surface of an ingot within said mold.

2. In an apparatus of the character described, an ingot stripping stool comprising a frame having centrally disposed upstanding substantially stationary ram, levers pivotally mounted on horizontal axes and having steps at their lower end portions to support a mold, means for yieldingly urging the stepped portions of the levers toward said ram, and means on the levers to facilitate movement of the step portions away from the ram.

3. An ingot stripping stool comprising a frame having an upstanding substantially centrally disposed ram projecting from its bottom, levers pivotally mounted on the frame for movement about horizontal axes and having mold supporting portions, yielding means for moving the mold supporting portions of the levers toward said ram,

and means on the levers to facilitate movement of said mold supporting portions away from said ram.

4. An ingot stripping stool comprising a frame having a bottom and upstanding portion, a stationary ram projecting upwardly from the central portion of said bottom, bellcrank levers having their upper end portions pivotally mounted for movement about horizontal axes arranged on the upstanding portion of said frame, mold supporting steps provided on the lower portions of said levers, yielding means for moving said steps toward said ram, and ears projecting from the upper end portions of said levers to facilitate movement of said steps away from said ram.

5. Ingot stripping mechanism comprising a stool having an upstanding substantially stationary ram, said ram being adapted to extend slidably through the bottom of a mold, levers pivotally mounted on the stool and provided with steps to support the mold, yielding means for moving the step portions of the levers toward the ram, said levers having projecting ears, crane links engageable with said ears for moving the step portions of the levers away from the ram, a member engageable with the mold, and means for moving the links and member in opposite directions for swinging the levers out of mold supporting position and for moving the mold downwardly.

6. In ingot stripping mechanism of the class described, a stool, levers pivotally supported by the stool and provided with means for supporting the mold on the stool, releasable means for holding the levers in mold-supporting position, and a ram projecting upwardly from the bottom portion of the stool and adapted to extend through the bottom of said mold for supporting an ingot within the mold while the mold is moved relatively to said stool, said releasable means including springs for yieldingly urging the levers toward mold-supporting position.

'7. In ingot stripping mechanism of the class described, a stool, levers pivotally supported by the stool and provided with means for supporting the mold on the stool, releasable means for holding the levers in mold-supporting position, and a ram projecting upwardly from the bottom portion of the stool and adapted to extend through the bottom of said mold for supporting an ingot within the mold while the mold is moved relative- 1y to said stool, said releasable means including bell crank levers engageable with said levers for limiting the movement of the levers in directions away from said ram.

8. In an ingot stripper stool of the character described, a hollow frame having a top opening of sufficient size to receive a conventional ingotstripping mold, supports journaled in the frame and adapted to support an ingot mold while the latter contains an ingot, a stripping ram rigidly secured to the bottom of the frame and projecting upwardly to contact the lower surface of an ingot Within the mold, and means projecting from opposite sides of the frame andadapted to be engaged by the links of a stripping crane for releasing the supports from the mold to allow relative axial movement of the ram and mold.

OSSIAN HIVELY.

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