US2757038A

US2757038A - Grapple attachment for tongs

Info

Publication number: US2757038A
Application number: US253620A
Authority: US
Inventors: Ervin A Drill
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-10-29
Filing date: 1951-10-29
Publication date: 1956-07-31
Anticipated expiration: 1973-07-31

Description

July 31, 1956 E. A. DRILL GRAPPLE ATTACHMENT FOR ToNGs 2 Sheets-Sheet 1 July 3l, 1956 E. A. DRILL GRAPPLE ATTACHMENT FOR TONGS 2 Sheets-Sheet 2 Filed Oct. 29 1951 United gStates Patent GRAPPLE ATTACHMENT Fon ToNGs Ervin A. Drill, Duluth, Application October '29, 1951, Serial No. 253,620 3 Claims. v(ci. 294-106) This invention relates to a grapple attachment for tongs, such as those designed for lifting metal ingots or other heavy articles.

Tongs with which the grapple of the present invention can be used include a vertically movable cross-head, tong arms pivoted at their mid-portions to said crosshead, and a guide piece which is situated above said crosshead and slidably'reeeives the upper ends of said tong arms. An upwardly extending operating rod is connected to the crosshead for raising and lowering it and thus spreading or closing the lower ends of the tong arms. A number of specific embodiments of such tongs are shown in Van Syckle Patent No. 2,215,844,`dated September 24, 1940, Harry Patent No. 2,219,479, dated October 29, 1940, and Hunter et al. Patent No. 2,394,779, dated February l2, 1946, although it is apparent that thel grapple of the present invention is not restricted to use with the particular tongs these patents show, but can beused with any tongs of similar general construction.

An object of the present invention is to provide a grapple suitable for installation on the tong arms of the foregoing type of tongs and to be opened and closed by the tong operating mechanism for handling loose material or other loads not readily handled by the tongs directly.

A further object of the invention is to provide an irnproved grapple which includes pivotally interconnected toggle links and prongs tixed to said links, which prongs can be positively closed on a load by throwing the toggle links above their dead center position and opened for releasing a load by throwing the links to or below said position.

A further object is to provide a grapple which has the aforesaid features and is suitable for installation on existing standard type tongs and to be operated thereby.

In accomplishing these and other objects of the invention, I have provided improved details of structure, a single form of which is shown in the accompanying drawings, in which:

Figure 1 is a side elevational view of a set of ingot tongs equipped with a grapple embodying features of the present invention, the toggle links being approximately in their dead center position;

Figure 2 is a view similar to Figure 1, but showing the toggle links raised above their dead center position;

Figure 3 is an elevational view taken at right angles to Figures 1 and 2;

Figure 4 is a horizontal sectional View taken substantially on line IV-IV of Figure 1; and

Figure 5 is a fragmentary View similar to Figures l and 2, but showing the toggle links below their dead center position.

Figures l and 2 show part of a typical set of tongs which comprise a crosshead 10,

tong arms

12 and 13 pivoted at their mid-portions to said crosshead, and a guide piece 14. A tubular stem 15, which is rigidly attached to the guide piece, supports the tongs from an overhead crane, not shown. The upper ends of the tong arms carry pins 16 and 17 which are slidably received in downwardly'dive'rgingslots 18 and 19 in the guide piece. An operating rod 20 is attached to crosshead 10 and extends upwardly through stem 15. The tongs include suitable mechanism, such as a rack and pinion, not shown, for raising and lowering this rod with respect to the stem. When the rod and crosshead are raised, the lower ends of the tong arms'sprfead apart. When the rod and crosshead are lowered, the lower ends of the tong arms close for grasping an article. Reference can be made to any of the patents hereinbefore mentioned for a more detailed disclosure of tongs of this sort.

The tong arms are shown equipped with a grapple 21 which is constructed in accordance with the present invention. Said grapple includes

fittings

22 and 23 rigidly attached to the lower ends of the tong arms, as by bolts 24. In practice these ttings can be installed in place of the bits with which the tong arms commonly are equipped, and the bolts 24 can be inserted throughk the openings in the tong arms which normally receive these bits. Hinge members 25 and v26 are pivotally attached to the fittings 22 and 2 3.k Toggle

links

27 and 23 of U-shape in plan are rigidly attached at their outer or bight portions to said hinge members. The free ends of said toggle links are pivotally interconnected on

pivot pins

29 and 30, which in turn are attached to the ends of a hinge bar 31. The bight of toggle link 27 carries a plurality of prongs 32, in this instance two, and the bight of the other toggle link 28 carries a plurality of prongs 33, in this instance three. The

prongs

32 and 33 extend downwardly from the respective bights and curve inwardly toward each other and have sharpened tooth-like extremities. The prongs 33 are staggered with respect to the prongs 32 so that they can intermesh when closed.

In operation, when the crosshead 10 and the operating rod 20 are raised to the limit permitted by engagement of pins 16 and 17 with the upper ends of slots 18 and 19 in the guide piece 14 and the

tong arms

12 and 13 thus have their maximum spread, the

toggle links

27 and 28 are fully extended and on dead center. This is the position Figure 1 shows. The stem 15 now can be lowered to lower the grapple and pick up a load. As the grapple descends, its

prongs

32 and 33 engage the surface on which the load is resting and move inwardly toward each other. Such movement throws the toggle links above their dead center position, as shown in Figure 2.

In this position the sharpened extremities of the prongs can bite into the sides of an article, such as a relatively soft or friable slag chunk, or they can engage surface irregularities in harder articles. Otherwise simultaneous lowering of the operating rod 20 and raising of stem 15 can fully close the prongs and cause them to intermesh for picking up a hard, smooth-faced article of a size not too large to be encompassed Within the prongs and toggle links when the prongs are closed. In either instance the load is heldsecurely and can be moved about as desired.

To release the load, the operating rod again is raised to spread the tong arms and move the toggle links back to their dead center position. The prongs thus spread apart and drop their load. If the operating rod again is lowered the toggle links are thrown below their dead center position to spread the prongs farther apart. Figure 5 shows this last position.

From the foregoing description it is seen that the present invention furnishes a grapple of simple and rugged construction for use on standard type tongs. One purpose for which I have found the grapple particularly useful is in conjunction with ingot tongs for cleaning a soaking pit of slag accumulations. The tongs are available at the pit for handling ingots and, by temporarily installing the grapple in place of the usual bits, the operator can use them also for cleaning out the slag.

While I have shown and described only a single embodiment of the invention, it is apparent that modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope Vof the appended claims.

I claim:

1. In combination with a set of tongs which includes a vertically movable crosshead, a pair of tong arms pivoted at their mid-portions to said crosshead, and a guide piece slidably receiving the upper ends of said tong arms, and in which raising said crosshead spreads the lower ends of said tong arms and lowering said crosshead closes the lower ends of said tong arms, a grapple comprising a pair of toggle links of U-shape in plan, means pivotally interconnecting the free ends of said links, means hingedly connecting the bights of said links with the lower ends of said tong arms, and a plurality of downwardly extending inwardly curved prongs carried by the bights of said links, said links occupying a dead center position and said prongs being open when the lower ends of said tong arms are fully spread, said prongs being adapted to hold a load when said links are thrown above their dead center position on closing of the lower ends of said tong arms.

2. In combination with a set of tongs which includes a vertically movable crosshead, a pair of tong arms pivoted at their mid-portions to said crosshead, and a guide piece slidably receiving the upper ends of said tong arms, and in which raising said crosshead spreads the lower ends of said tong arms and lowering said crosshead closes the lower ends of said tong arms, a grapple comprising a pair of toggle links of U-shape in plan, means pivotally interconnecting the free ends of said links, ttings attached to the lower ends of said tong arms and hingedly connected to the bights of said links, and a plurality of downwardly extending inwardly curved prongs xed to the bights of said links, the prongs on one bight being staggered with respect to those on the other so that the prongs can intermesh, said links occupying a dead center position and said prongs being open when the lower ends of said tong arms are fully spread, said prongs closing and being adapted to hold a load when said links are thrown above their dead center position on closing of the lower ends of said tong arms.

3. The combination, with a set of tongs which includes a vertically movable crosshead, a pair of tong arms pivoted at their mid-portions to said crosshead, and a guide piece slidably receiving the upper ends of said tong arms, of a grapple comprising fittings attached to the lower ends of the respective tong arms, hinge members pivoted to the outside of the respective ttings, U-shaped toggle links xed at their bights to the respective hinge members and extending between the two tong arms and being pivotally connected together, and a plurality of downwardly extending prongs xed to the bights of said links, said links being adapted to move either above orbelow a dead center position to engage said prongs with a load or to drop the load, said links in their dead center position being beneath the lower extremities of said tong arms.

References Cited in the tile of this patent UNITED STATES PATENTS Smith Feb. 26, 1952