US2076494A - Lifting tongs - Google Patents

Description

April 6, 1937.

A. CAMEROTA ET AL 2,076,494

LIFTING TONGS 5 Sheets-Sheet '1 Filed March 20, 1936 INVENTORS: 7 Loans 9. Camzmta &

ORNEYS.

April 6, 1937.

L. A. CAMEROTA Ef L 2,076,494

LIFTING TONGS 5 Sheets-Sheet, 2

Filed March 20, 1936 INVENTORS: is fiL'amzroi/a 5 701m milack TORNEYS WITNESSES:

Lou

April 6, 1937. I A. CAMEROTA ET AL I 2,076,494

LIFTINGTONGS Filed Mai-ch 20, 1956 5 SheetSheet 5 FIG: I

WITNESSES: INVENTORS:

I 1 TORNEYS.

April 6, 1937.

WITNESSES:

L. A. CAMEROTA ET AL 2,076,494

' 'L IFTING TONGS 5 Sheets-Sheet 5.-

Filed March 20, 1936 INVENTORS! Laws .6? L'mmemtazz RNEYS.

; By John Mail/adv,

Patented Apr. 6, 1937 UNIT STATES PATENT OFFICE LIFTING TONGS Application March 20, 1936, Serial No. 69,804

16 Claims.

Our invention relates generally to lifting tongs and more particularly to flask hooks, though it is obviously applicable to the lifting and transporting of various other heavy objects. Our par- 5 ticular invention is directed to the handling of hot flasks used in pipe casting. The task of engaging and disengaging lifting hooks with hot flasks is recognized as both diflicult and dangerous when done by a man stationed at the flasks. The danger from molten metal to the man operating the hooks at the flask is great. The delays in handling because of the slow and awkward manual operation in engaging and disengaging the hooks are costly and retard the plant production, particularly when flasks are handled in pairs or larger groups.

Consequently one of the objects of our invention is the avoidance of this unnecessary, dangerous and slow manual labor in disengaging and engaging flask hooks by making the operation automatic to the extent that it is controlled and performed by the crane operator by the manipulation of his hoisting controls. A further object of our invention is the provision of such a device for handling the cylindrical pipe flasks in groups instead of singly. Effectiveness, speed and positiveness of action, and reliability are also objectives to which our invention is directed. Other objects and advantages will be apparent from a detailed description of a preferred embodiment thereof which follows and which has reference to the accompanying drawings of which:

Fig. I is a front elevation of a lifting device.

Fig. II is an end view of a lifting device.

Fig. III is a plan view of the same.

Fig. IV is a central section of the lifting device about to be lowered over a pair of pipes.

Fig. V is a view similar to Fig. IV showing the parts in a difierent position.

Fig. VI is a View similar to Fig. IV showing the device carrying a pair of pipes; and

Fig. VII is a simplified form of the device for carrying a single pipe.

For the purposes of a detailed description of 45 the device shown in the drawings that device may be resolved into the following elements: operating tongs I, follower tongs 2, side members 3, operating arms 4, head 5, suspension member 6, spreaders 7, connecting rods 8, and spreader 50 hook H.

The hook-like tongs l and 2 are pivotally supported by the side members 3 between an inner element l3 and an outer element M of the side members 3. The outer element M at each end 55 of the device has supporting legs 15 which take the weight of the device when resting on the ground instead of the tongs l and 2 and without interfering with pipe flasks l0 being transported. The tongs l and 2 work on pivot rods l6 which extend the length of the device between the two side members 3.

For each operating tong I there is a follower tong 2 to which it is pivotally joined by the connecting rod 8. There is an operating tong l and a follower tong 2 in each pair of tongs and the operating tong l of one pair is connected to the corresponding follower tong 2 of the other pair. Thus the right hand members of each pair of tongs are moved together according to the motion of the actuating tong I and the left hand members operate in a like manner. The inner elements l3 and the outer elements l4 of the side members 3 are separated by spacing rods 23 to allow the free pivotal operation of the tongs i and 2; the side members 3 at each end of the device are also spaced by the spacing rods 20.

Each tong I has an operating arm 4, which is made upof upper and lower pieces 22 and 23 and pivotally joined by integrating rods 24 and 25 respectively. The rods 24 and 25 join the pivotal points of corresponding operating arms 4 on each end of the device. The operating arms 4 at the same end of the device are pivotally connected to the head 5 by means of a bolt 29v supported by brackets 21 which are fastened to the top of the head 5. The upper parts of the operating arms 4 are curved in an obvious manner to allow them to close without interference from the head 5.

Pivotally attached to the corresponding operating arms 4 at each end of the device are spreaders l which are joined at their outer ends by integrating rod 28 secured with nuts. These spreaders I are mounted on the rod 24 but obviously could be attached to the arms-4 in other ways and at other points. Each spreader T has formed in its underside an engagement element IS in the form of a notch for engaging rod 25. The rod 25 functions as a'stop which the spreaders I ride on and fall into engagement with. The spreaders l are curved downwardly from the ends in order to prevent interference by contact with the head 5 at the central portions of the spreaders 'l.

The spreader hook I l is pivotally attached to a bracket 32 which is attached to the suspension member 6. At the lower end of the hook H is a guiding surface 33 which-engages an integrating 'rod 34 secured between the spreaders l as the suspension member 6 is lowered. This guiding surface 33 is designed to guide the rod 34 into hooking engagement with the hook II by causing the hook II to swing away from the vertical as the suspension member 6 is lowered until the hook I I slips back into place under the rod 34. It is important that the hook II at no time engage the rod 34 on the side of the hook I I opposite from the guiding surface 33. Consequently the upper portion 36 of the hook II is extended inward toward the suspension member 6 and the engagement of the portion 36 with the suspension member 6 prevents the hook I I from swinging into a position beyond the rod 34.

The head 5 is of heavy construction and is made up of two strong channels 3'! riveted to a central plate 38 to form an I-beam. At the middle of the head 5, the suspension member Ii is positioned with capacity for limited vertical movement. The suspension member 6 extends around the head 5 and is composed of side plates'40- secured to top pieces M and to a bottom piece 43. The top pieces 4I separated by an eye piece make up the top piece, with rivets 44 passing through all three of these pieces. Removable bolts attach the side plates 40 to the bottom piece 43. On each side of the suspension member 6 are guide brackets 45 attached to the head 5. These guide brackets 45 guide the suspension member 6 in the longitudinal plane of the device while the sliding contact of the plates 40 with the flanges of the channels 3'! guide it in the transverse plane. A strengthening piece 46 is riveted to each side of the head 5 at its central portion.

The simplified form of this device shown in Fig. VII handles but one pipe: flask Ill at a time; the construction is clearly understandable from the above description of the two-flask type. In the simplified form there are no follower tongs 2 and no connecting rods 8, but otherwise the construction is the same as the two-flask type.

In describing the operation of our device it will be assumed that there are two pipe flasks on the ground awaiting transportation. The lifting tongs are braced in their open position by lowering the head 5 and suspension member 6', while the device is on the ground, until the spreaders I become locked in engagement with rod 25, as shown in Fig. 11. As the device is raised by a crane or other hoisting means the tongs I and 2 remain in the open position because of the bracing action of the spreaders 'I. The crane operator then lowers the device over the two pipe flasks I0 as shown in Fig. IV until the legs I 5 of the device rest on the ground straddling the flasks. The suspension member 6 is further lowered by the crane operator until the spreader hook II drops into its engagement position under the rod 34 as shown in Figs. II and V. The device is now lifted and the hook II lifts the spreaders I out of engagement with the rod 25 allowing the operating arms 4 to operate and close the tongs I and 2 about the flasks III, as shown in Fig. VI. The operating arms 4 operate the operating tongs I which in turn operate the follower tongs 2 through the connecting rods 8. The device and flasks III are now lifted and transported by the crane operator to the place of deposit where he lowers the device and pipe flasks I0 onto the ground further lowering the suspension member 6 and the head 5 until the spreaders 'I again engage the rod 25. The crane operator now agitates the suspension member 6 causing the spreader hook II to swing clear of the rod 34 at which moment the operator skillfully lifts the suspension member 6 and completely disengages the spreader hook I I from the rod 34. The weight in the end of the spreader hook II facilitates this operation On the part of the crane operator and with a little practice the operation can be performed easily and quickly by the skilled crane operator. Once the spreader hook II is thus disengaged the crane operator may lift the device in its open position clear of the deposited pipe flasks Ill and his task is completed, the device being braced in its open position ready for engagement with other pipe flasks I0.

Thus our invention provides efficient lifting tongs for the handling of pipe flasks without endangering operators near the hot flasks. Dangerous and slow manual labor is eliminated and control placed inthe hands of the crane operator. A

. plurality of flasks may be efliciently handled at one time and it is obvious from the above described apparatus that additional tongs may be included in a modification of the device for the handling of more than two pipe flasks. The operation of this device is simple and positive with no danger of dropping the pipe flasks once engagement has been accomplished.

While we have described the preferred form of our invention with also a simplified form thereof, in some detail, it will be obvious to one skilled in the art that numerous changes and modifications can be made in the device as described without departing from the spirit of our invention as pointed out and claimed in the following claims.

Having thus described our invention, we claim:

1. A lifting device comprising a head, operating arms pivotally attached to the head, said operating arms including pivotally attached upper and lower members, tongs formed on the lower members and pivotally connected to operate as a pair, a spreader pivotally attached at one end to one of the operating arms and restingon a stop member attached to the other of the arms, said spreader having an engagement means for engaging said stop member, and a suspension member movably attached to the head and carrying a spreader hook to automatically engage the spreader when the suspension member is in the down position.

2. A lifting device according to claim 1 characterized further by the fact that the spreader is pivotally attached to one of the arms at the juncture of its upper and lower member, that the stop on which the spreader rests is positioned at the juncture of the upper and lower members of the other arm, and that the spreader is curved downwardly from the ends.

3. A lifting device according to claim 1 characterized further by the fact that the suspension member is attached to the head with capacity for guided vertical movement and the end of the spreader hook is inclined to guide the hook into engagement with the spreader.

4. A lifting device according to claim 1 characterized further by the fact that the spreader has a hooking member for engagement with the spreader hook.

5. A lifting device comprising an elongated head, operating arms pivotally attached at each end of the head, said'operating arms including pivotally attached upper and lower members, tongs formed on the lower members and pivotally connected to operate in pairs, integrating rods connecting the corresponding arms at the ends of the head to operate integrally, a spreader pivotally attached at one end to the arms on one side of the head and resting on a stop member attached to the arms on the other side of the head, said spreader having an engagement means for engaging said stop member; and a suspension member movably attached to the central portion of the head and carrying a spreader hook to automatically engage the spreader when the suspension member is in the down position.

6. A lifting device according to claim 5 characterized further by the fact that there is an additional spreader joined to the first mentioned spreader by rods, and the stop on which the spreader rests is also a rod extending between two arms at opposite ends of the device.

7. A lifting device according to claim 5 characterized by the further fact that the integrating rods form the pivots by which the upper and lower sections of the arms are joined, and that the spreader is pivotally attached to one of these integrating rods and rests on the other as a stop member.

8. A lifting device comprising a beam-like head, operating arms pivotally attached at each end of the head, said operating arms including pivotally attached upper and lower members, tongs formed on the lower members and pivotally connected to operate in pairs, integrating rods connecting the pivots of the corresponding arms at the ends of the head to operate integrally, curved spreaders pivotally attached at one end to the integrating rod joining the pivots of the arms on one side of the head and resting on the integrating rod joining the pivots of the arms on the other side of the head, said spreaders having engagement notches on their undersides and being joined by integrating rods, a suspension member attached to the central portion of the head with capacity for vertical guided movement, and a spreader hook with a guiding surface at its end attached to the suspension member to automatically engage one of the integrating rods between the spreaders when the suspension member is in the down position.

9. A lifting device comprising an elongated head, a pair of operating arms pivotally attached at each end of the head, said operating arms including pivotally joined upper and lower members, integrating rods connecting the arms on each side of the head, operating tongs formed on the lower members, said operating tongs at each end of the head being the opposing members of a pair and operating in opposite directions, side members pivotally joining the operating tongs at each end of the head, follower tongs pivotally attached to the side members in pairs with the operating tongs, connecting rods joining the operating tongs to corresponding follower tongs on each side piece, a spreader pivotally attached at one end to the arms on one side of the head and resting on a stop member attached to the arms on the other side of the head, said spreader having an engagement notch for engaging said stop member, and a suspension member movably attached to the central portion of the head and carrying a spreader hook to automatically engage the spreader when the suspension member is in the down position.

10. A lifting device according to claim 9, characterized further by the fact that said side members are interconnected by integrating rods.

11. A lifting device according to claim 9 characterized further by the fact that said side members extend below the operating tongs in all positions thereof, and that said side members have formed therein work openings aligned with the pairs of tongs.

12. A lifting device according to claim 9 characterized further by the fact that there is an additional spreader attached to the first mentioned spreader by integrating rods and that one of the spreader integrating rods is in line with said spreader hook for engagement therewith.

13. A lifting device according to claim 9 characterized further by the fact that the suspension member is movably attached to. the head with capacity for guided vertical movement and that the spreader hook is suspended over the spreader and has a guiding surface formed on its lower end.

14. A lifting device comprising a head, a pair of operating arms pivotally attached to the head, said operating arms including pivotally joined upper and lower members, opposing operating tongs formed on the lower members, side members pivotally joining the operating tongs, follower tongs having operating levers and pivotally attached to the side members in pairs with the operating tongs, connecting rods joining the operating tongs to corresponding follower tongs, a spreader pivotally attached at one end to an operating arm and resting on a stop attached to the other operating arm, said spreader having an engagement notch for engaging the stop, and a suspension member movably attached to the central portion of the head and carrying a spreader hook to automatically engage the spreader in the down position of the suspension member.

15. A lifting device comprising a head, interconnected grappling tongs, operating arms connecting the head and tongs, a substantially horizontally disposed movable spreader for locking the operating arms with the tongs in an open position, said spreader having capacity for movement to unlock said operating arms, a suspension member movably attached to the head and having a spreader hook for engaging the spreader in the down position of the suspension member.

16. A lifting device comprising a head, interconnected grappling tongs, operating arms connecting the head and tongs for pulling the tongs shut when lifted, a movable spreader means for automatically keeping the grapping tongs open when empty, said spreader having capacity to swing to an inoperative position to allow the grappling tongs to close, means for operating said movable spreader means according to the suspension position of the lifting device, whereby the tongs are locked open in one suspension position and open freely in another suspension position.

LOUIS A. CAMEROTA. JOHN MATLACK.

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