US2345391A - Stripper tong - Google Patents

Description

March 28, 1944. w. w. GROSSETT STRIPPER TONG Filed April 23, 1942 2 Sheets-Sheet l W. W. GROSSETT Filed April 25, 1942 2 sheets'sheet 2 X 4. K M

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Patented Mar. 28, 1944 UNITED STATE STRIPPER TONG William W. Grossett, uiihan. Pa," assignor to Carnegie-Illinois Steel Corporation, a corporation of New Jersey Application April 23, 1942, Serial No. 440,227

'2 Claims. (01. 22-95) This invention relates to improvements in stripper tongs for the removal of sticking hot tops from metal ingots and the like.

Hot tops frequently stick to steel ingots and molds, making it impossible to strip the same by the" usual expedient of lifting off with a crane. The general practice with such stickers is to swing the elevated mold, ingot and hot top against other molds, or to drop the same quickly to the ground, in an attempt to jar the hot top loose. Such procedure is extremely hazardous to workmen and equipment, and is not successful in many instances, it being necessary to finally free the hot top by burning with a torch. I It is an object of my invention to provide for the removal of such sticking hot tops and the like bythe positive application of separation forces to the hot top and ingot, and efficiently utilizing the weight of the hot top, mold and ingot without externally applied weight.

The invention contemplates a stripper tong suspended from a crane in the usual manner, comprising an efficient lever system capable of exerting opposite forces upon the ingot and hot top so as to separate the same upon lifting their entire mass, the tong utilizing and multiplying the potential force of the weight of said mass to efiect such separation.

f Additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings,

wherein:

Fig. l is an elevational view of an embodiment of my invention, showing the tong in initial engagement with a hot top;

Fig. 2 is a similar view, partly in section, illustrating the tongin stripping position;

Fig. 3 is a top plan view of Fig. 2;

Fig. 4 is a side elevational view thereof;

Fig. 5 is a side view, showing a modification; and

Fig. 6 is a detail view, partly in section, of a portion of Fig. 1, showing the limited travel of the tong levers.

Referring to the drawings, 2 designates an ingot mold supplied with a hot top 3, into which an ingot 4 has been poured. Such hot tops generally include a flanged or enlarged head 6 having oppositely disposed lugs 8, a pair of trunnions I, being disposed adjacent the lower limits of the head 6 and the lugs 8 extending at right angles to the trunnions adjacent the top of the head.

In the event that the hot top 3 sticks to the iii by means of a crane, I have provided an improved stripper tong, illustrated in the drawings in engagement with the hot top, whereby through suitable leverage, the hot top is forcibly separated from the ingot and ingot mold.

In the form of Figs. 1 through 4, the hot top 3 is shown in position on the ingot mold with the hot top poured full, in which case the top of the ingot is substantially flush with the upper surface of the hot top. My stripper tong engages the top face of the ingot as by means of a central fulcrum block 9 suspended from a crane hook H) in the following manner. Oppositely disposed second class levers l3 are pivoted on opposite sides of the fulcrum 9 in laterally spaced relation, as at I4, to projecting lugs Ma, said levers being suspended by their outer terminals from a supporting eye [2 by means of chains l5. ll designates a safety chain extending from the fulcrum block 9 to the lifting eye l2.

Each of the levers l3 pivotally supports a depending hook IB, said hooks being in the form of stirrups freely pivoted at the-upper edges of the levers I3 by engagement of the upper transverse portions ll of the hooks in notches I8 formed in said levers. The lever arms fromthe pivot points l4 of the levers to the pivotal engagement l'||8 with the hooks l6 are considerably less than the lever arms from said pivotal supports of the hooks 16 to the chain-actuated terminals of the levers, thereby providing a substantial mechanical advantage upon upward pivotal movement of the levers with respect to their common fulcrum block 9. Hence, upon engaging the hooks I6 with the hot top lugs or beneath the enlarged head of the hot top, with-levers l3 lowered as shown in Fig. 1 an upward movement of the levers, as by the crane hook 10 through chains 15, with the fulcrum block 9 in engagement with the top of the ingot, will exert a substantial force downwardly upon the ingot and upwardly upon the hot top. As the entire mass of ingot mold, ingot and hot top is lifted free by the crane and tong, the entire weight of said mass is converted into a substantial separating force, stripping the sticking hot top from the ingot and mold.

For example, assuming the combined weight of the ingot and mold to be ten tons, the total force stripping the hot top from the mold and ingot will be equal to the product of said weight and the mechanical advantage obtained by the proportions of the levers I3 and their associated linkage. Thus, if the leverage of the pair of tong mold and ingot, resisting withdrawal thereof levers I3 is seven, the stripping force availabl will be equivalent to seventy tons in the above illustration. It should be noted that the ad vantage thus obtained does not materially increase the load on the crane, since the total dead load upon the crane is only the weight of the mass of the ingot mold, ingot and hot top plus the weight of the tong, the latter not appreciably exceeding the weight of the usual spreader hooks or other devices generally employed in crane operation.

For the purpose of preventing the tongs from jack-knifing or collapsing, the fulcrum lugs M and the levers l3 are each provided with coacting faces, as particularly shown in Fig. 6, including angularly related faces a and b formed upon the end faces of the lugs I4, and a face formed within the bifurcated ends of the levers 13, said faces coacting to function as limiting stops respectively defining the upward and downward pivotal travel of the levers I3. As shown in Figs. 1 and 6, the faces ,b and c may become engaged upon engaging or releasing the tong, whereby the levers 13 are prevented from over-V travel and collapse .of the tong. Similarly, in Fig. 2, or when the tong issuspended freely, the faces a and c coact to prevent excessive upward travel of the levers I3 and thereby prevent jack-knifing of the tong. By these means, the tong is always positioned for use without manual adjustment.

The hooks 16 are provided with spaced inturned terminal lips I -9 for engagement beneath the enlarged head of the hot top, said hooks also having intervening connecting straps 20 between said lips for engagement with the hot top lugs 8', when desired, as shown in Fig. ;5 Retainer guards 2! are provided on the levers 13, extending over the pivotal engagement l 1-! 8 of hooks IS with said levers, and handles 22 are provided on the hooks l5 for assisting the en? gagement and disengagement of the hooks and the hot top. 7 v 5 illustrates a modification wherein the fulcrum block 9 is provided with a lower extension -.9*, removably secured to the block 9 as by means of lugs 23 and a through pin 24. The extension of the fulcrum block as shown, permits the use of my stripper tong with hot tops which have been pouredlow or short, whereby the upper surface of the poured ingot terminates within the hot top some distance below the upper surface of the latter. In using the tong in this manner, the hooks I6 are engaged with the upper pair of lugs 8, as by means of the supporting straps 20.

It will therefore be seen that I have provided a simple and efilcient stripper tong utilizing thepotential force of the weight of the mass of the ingot mold, ingot and sticking hot top, for stripping the latter from the ingot and mold. My

invention enables the stripping of troubiesome,

persistent sticking hot tops in a minimum time, and without the hazard to workmen and equipment attendant upon the former practice of attempting to jar the hot top loose by swinging and bumping the same from the crane.

Various changes and modifications are contemplated within the scope of the following claims.

I claim: 1. A stripper tong of the character described including a central ingot-engaging fulcrummember, a pair of opposed levers pivoted thereto, a hot top engaging hook pivotally depending from each lever adjacent the pivotal attachment of the latter with the fulcrum member, lifting chains connecting the outer ends of the levers in spaced relation to the hooks with a common lifting eye, the levers and chains supporting the weight of the mass carried by the hooks, said levers exerting a downward force upon the fulcrum member and ingot, and an upward force upon the hooks and hot top equal to a multiple of the force corresponding to the weight of said mass, said fulcrum member and levers having coacting faces limiting the upward and downward pivotal movement of said levers to thereby prevent collapse of the tongs.

2. A stripper tong of the character described including a central ingot-engaging fulcrum member, a pair of opposed levers pivoted thereto in laterally spaced relation on opposite sides of said member, a hot top engaging hook depending from each lever adjacent the pivotal attachment of the latter with the fulcrum member, said hooks being of stirrup formhaving transverse portions pivotally supported on their respective levers and having spaced inturned terminal lip the ps of ea ho k h n ntervening connecting straps, lifting chains connecting the outer ends of the levers in spaced relation to the hooks with a common lifting eye, the levers and chains supporting the weight of the mass carried by the hooks, said levers ex.-

erting equal and opposite forces upon the fulcrum member and ingot, and upon the hooks and hot top, the magnitude Of-said force being a multiple of the force corresponding to the weight of said mass, said fulcrum member and levers having coacting faces limiting the upward and downward pivotal movement, of said levers to thereby prevent collapse of the tongs.

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