US2994554A

US2994554A - Tongs

Info

Publication number: US2994554A
Application number: US699549A
Authority: US
Inventors: Robert J Harry
Original assignee: Alliance Machine Co
Current assignee: Alliance Machine Co
Priority date: 1957-11-29
Filing date: 1957-11-29
Publication date: 1961-08-01
Anticipated expiration: 1978-08-01

Description

R. J. HARRY Aug. 1, 1961 TONGS 2 Sheets-Sheet 1 Filed Nov. 29, 1957 Fig.l.

INVENTOR Robert J. Hurry 1961 R. J. HARRY 2,994,554

TONGS Filed Nov. 29, 195'! 2 Sheets-Sheet 2 Fig .3.

Fig .4. 1e

INVENTOR Rob art J. Hurry United States Patent TONGS Robert J. Harry, Alliance, Ohio, assignor to The Alliance Machine Co., Alliance, Ohio, a corporation of Ohio Filed Nov. 29, 1957, Ser. No. 699,549 4 Claims. (Cl. 294-111) The present invention relates to tongs and particularly to an improved construction of tongs to increase their gripping power for lifting ingots or the like. Since the surface of an ingot and particularly a cold ingot is relatively hard, the tendency of tongs to slip is pronounced and presents an ever present danger of permitting an ingot to slip from the tongs after the ingot is lifted from the floor of the soaking pit or is in transport from the soaking pit. Such slips are serious and dangerous.

By the present invention, I provide a tong structure whichprovides gripping power far beyond anything heretofore possible. In my present structure, the gripping power of the tongs is multiplied many .times over that of conventional tongs and over the weight of both the ingot and the tong structure.

I provide a vertically movable column, tong grips pivotally mounted on the column, means engaging the tong grips to impart a gripping motion to the latter, multiplying sheaves and cables supporting the tong engaging means, column cables and a sheave supporting the column for movement independently of the tong engaging means, drive means for driving the column cables, means for releasing the column from the column cables onto the tong grips and second drive means for driving the multiplying sheave cables. Preferably the multiplying sheaves act on a crosshead carrying an actuating rod which in turn carries the tong engaging means. Lost motion means are preferably provided between the column cables and the column whereby the weight of the column is,tr,ansferred to the tong grips and thereby onto the tong engaging means.

In the foregoing general description of my invention, I have set out certain advantages, purposes and objects of the present invention. Other objects, advantages and purposes will be apparent from a consideration of the following description and the accompanying drawings in which- FIGURE 1 is a side elevation partially in section of the tongs according to my invention with the tongs in open position;

FIGURE 2 is a side elevation partially in section of the tongs of FIGURE 1 with the tongs in closed position; and

FIGURE 3 is a section on the line III-III of FIG- URE 1.

FIGURE 4 is a schematic isometric view of the cable reeving of the tongs of FIGURES 1-3.

Referring to the drawings, I have illustrated an overhead bn'dge girder carrying rails 11. .A trolley frame 12 extends from one side of girder 10 to the other and is provided with wheels 13 adapted to move on rails 11. A vertically movable travelling column 14 is suspended through an opening 15 in trolley frame 12 by means which will be more fully described hereinbelow.

A main hoisting drum 16 is suitably mounted on the trolley frame 12 at one side of opening 15. Two sets of

cables

17 and 18 are fixed at one end to drum 16 and are taken up or released by rotation of the drum. One set of cables 17 pass around sheave wheels 19 journaled in blocks 20 which are vertically slidable in elongated apertures 21 in the sides of column 14. The opposite end of cables 17 are wound upon a tongs operating drum 22 mounted on the trolley frame 12 on the side of opening 15 opposite the hoisting drum 16. The tongs operating drum 22 is operable independently of hoisting drum 16 to lower the sheaves 19 in aperture 21 so as to release the 2,994,554 Patented Aug. 1, 1961 Weight of column 14 from cables 17 for the purpose hereafter more fully explained.

Cables 18 pass from drum 16 around vertically mo'vable sheaves 23 and sheaves 24 which are journaled in the side walls of column 14. The

sheaves

23 and 24 make up a multiplying hoist arrangement. The other end of cables 18 are dead-ended on the trolley frame 12 through a shock-absorbing spring 25 or similar resilient shock-absorbing means. The movable sheaves 23 are mounted on a crosshead 26 in which is journaled a tong operating rod 27. Both the crosshead 26 and tong operating rod 27 are movable vertically centrally of column 14.

At the lower end of column 14 is journaled a tong head or housing 28 adapted for rotation centrally of the column. In the tong head are journaled spaced apart tong elements 28a each in the form of a bell crank. Each element is provided with a gripping end 29 carrying bits 29a adapted to engage the side walls of an ingot to pick it up. The opposite end 30 of each tongs element 28a is journaled on a pin 31 passing through one end of a link 32. The opposite end of link 32 is journaled on a pin 33 passing through the end 34 of operating rod 27 remote from sheaves 23.

In operation the drum 22 is actuated to raise sheave blocks 20 in apertures 21 until the weight of the vertical column is on cables 17. This releases cables 18 and causes column 14 to move upwardly with respect to rod 27. The upward movement of column 14 causes rod 27 to act on the tongs elements 28a to open them.

The entire column is then lowered by the rotation of hoisting drum 16 which pays out both

cables

17 and 18 to maintain the weight of column 14 on cables 17 while cables 18 remain sufficiently slack to maintain the tongs elements 28a in the open position. When the column 14 has been lowered so that the tongs 28a are in position to engage the ingot to be lifted, the drum 16 is stopped and drum 22 actuated to lower the blocks 20 in apertures 21. This shifts the weight of column 14 to cables 18 and

sheaves

23 and 24. The shift of weight causes column 14 to descend relative to rod 27 which remains stationary. This relative movement of column 14 and rod 27 acts through links 32 to raise ends 30 of the tongs elements thereby closing the gripping ends 29 and forcing bits 29:; into the side walls of the ingot being gripped. The multiplying

sheaves

23 and 24 cause a force to be exerted on rod 27 which is a multiple of the weight of column 14 and its attached parts, depending upon the number of times cables 18 are reeved over

sheaves

23 and 24. In this fashion, any desired multiplication of the column weight can be applied to the gripping elements so as to build up tremendous forces for the gripping action. As the load is picked up the weight of the load acts on the crosshead 26 and becomes an additional part of the effective load acting to produce the gripping force and is multiplied in the same ratio.

In a preferred form of my invention, I also provide means for rotating tong elements 27 so that the ingot may be suitably positioned for discharge or the tongs may be suitably positioned for engaging an ingot which has become askew in the soaking pit. I provide a drive motor 35 mounted on column 14 and movable therewith. A vertical drive shaft 36 is journaled along one side of column 14. One end of drive shaft 36 is driven by motor 35 through

spur gears

37 and 37a through a right angle drive 37b. The other end of shaft 36 carried a pinion 38 drivingly engaging a pinion 39 on the tong supporting head 28 which is journaled for rotation in the end of colunm 14 as previously indicated. The tong supporting head 28 may be rotated by energizing motor 35 thereby rotating the tong elements to any desired position for picking up or discharging an ingot.

While I have illustrated a preferred embodiment of this invention it will be understood that the invention may be otherwise embodied within the scope of the following claims.

I claim: 7

l. Ingot and like tongs including a pair of relatively vertically movable members, tong elements pivoted on one of said members, said tong elements having a gripping end extending from said one member and adapted to engage the ingot to be lifted, means on the other of said movable members engaging the tong elements opposite the gripping end to impart a gripping motion thereto, means for simultaneously suspending said members, said means including first suspension means for independently moving said one member on which the tong element is pivoted vertically independently of said other member during a portion of its vertical travel and second suspension means acting between the vertical movable members through a multiplying hoist linkage to simultaneously lift said members so as to release the said one member on which the tong element is pivoted from its independent suspending means and acting on both members in opposite directions through the multiplying hoist linkage urging the two members positively together by a force equal to the multiplying effect of the multiplying linkage and the weight of the two members, the tongs, and any load held thereby.

2. Ingot and like tongs comprising a vertical movable column, tong elements pivotally mounted on the column for engaging an ingot or the like, supporting cables for said column, and operating rod movable vertically of the column, link means on one end of the operating rod engaging the tong elements to open and close the tong elements, fixed sheaves in the column, sheave means supporting the operating rod at the end opposite the link means, second supporting cables reeved through the fixed sheaves and the sheave means on the operating rod in multiplying arrangement and active to move said sheaves together when the first supporting cables are released, and means for independently activating said first and second cables.

3. Ingot and like tongs including a vertically movable column, tong elements pivotally mounted on the column and adapted at one end to engage an ingot or the like, supporting cables for said column, an operating rod movable vertically centrally of the column, a crosshead movable in the column and supporting the operating rod, fixed sheave means in the column, sheave means on the cross head, second independently operable supporting cables reeved in multiplying relationship through the sheaves of the crosshead and the fixed sheaves, link means on the operating rod opposite the crosshead engaging the tong elements to exert a gripping force thereon, and means for independently operating the two sets of supporting cables whereby the weight of the column is shifted onto the second supporting cables and to the linking means, said linking means acting on the tongs with a force equal to a multiple of the column weight by reason of the multiple reeving of said second cables over the fixed sheaves and the sheaves on the crosshead.

4. Ingot and like tongs including a vertically movable column, tong elements in the form of hell cranks pivotally mounted in the column, said bell crank having a gripping end engageable on an ingot or the like, an operating rod movable vertically centrally of the column, supporting cables for said columns, a crosshead independently movable in the column and supporting the operating rod,- fixed sheave means in the column, sheave means on the crosshead, second supporting cables passing through the sheaves on the crosshead and the fixed sheave means whereby pressure exerted on the second cables causes the fixed sheaves and the sheaves on the crosshead to be drawn together, links on the operating rod opposite the crosshead engaging the ends of the bell cranks opposite the gripping ends to exert a gripping force thereon, means for releasing the supporting cables to shift the weight of the column onto the second supporting cables whereby the multiplying reeving on the crosshead sheaves and fixed sheaves acts to force the column and link together so that the link acts on the tongs with a force equal to a multiple of the column weight and the reeving on the fixed sheaves.

References Cited in the file of this patent UNITED STATES PATENTS 749,330 Sawyer Jan. 12, 1904 1,231,596 Gregg July 3, 1917 1,580,416 Cromwell et al Apr. 3, 1926 1,621,701 Yanney et a1. Mar. 22, 1927 1,779,702 Harrington Oct. 28, 1930 1,962,700 Allard June 12, 1934 2,076,494 Camerota et al. Apr. 6, 1937 2,587,217 Quenan Feb. 26, 1952 2,757,038 Drill July 31, 1956 2,815,242 Kenyon Dec. 3, 1957