US3287057A

US3287057A - Coil tongs

Info

Publication number: US3287057A
Application number: US431370A
Authority: US
Inventors: Warren H Gallapoo
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1965-02-09
Filing date: 1965-02-09
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22

Description

Nov. 22, 1966 w. H. GALLAPOO COIL TONGS 2 Sheets-Sheet 1 Filed Feb. 9, 1965 Illl/ INVENTOR.

Nov. 22, 1966 w. H. GALLAPOO 3,287,057

COIL 'IONGS Filed Feb. 9, 1965 2 Sheets-Sheet 2 INVENTOR. Warren H. aflapoa BY 637W United States Patent Office 3,287,057 Patented Nov. 2 2, 1966 3,287,057 COIL TONGS Warren H. Gallapoo, Jackson, Mich., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware Filed Feb. 9, 1965, Ser. No. 431,370 3 Claims. (Cl. 294-81) This invention relates to improved coil tongs, and particularly to four point, low headroom coil tongs The lifting of coils of sheet metal presents at least two problems. One is involved with achieving a wide range of jaw openings for the tongs without requiring a large amount of headroom being needed for the operation of the tongs.

Another problem is that of damaging of the coil during lifting of the coil by the tongs. Coils are damaged be cause of unequal or excessive pressure exerted on the coil by one or more of the jaws of the tongs.

Accordingly, a principal object of this invention is to provide improved four point coil tongs.

Another object of this invention is to provide improved four point coil tongs which do not require an excessive amount of headroom for operation.

A further object of this invention is to provide improved four point coil tongs in which pressure applied to the coil is substantially equalized among the four jaws of the tongs.

In accordance with this invention there is provided four point low headroom coil tongs using a non-powered linkage mechanism in conjunction with -a combination rack and pinion mechanism to achieve equal loading of the four jaws of the tongs. As the linkage is raised, each of the pinions which are coupled to a pair of jaws through racks are rotated, causing the racks, which are each free to move, to move until resistance is encountered by contact with a surface of the coil to be lifted. On meeting resistance by one rack, the pinion rotates, moving along the one rack and moving the rack which controls the other jaw of its pair of jaws. When both jaws meet equal resistance, rotation of the pinion produces no relative movement, but tightens both jaws of the pair equally.

The invention, as well as additional objects and advantages thereof, will best be understood when the following detailed description is read in connection with the accompanying drawing, in which:

FIG. I is a side elevational view, with part of the mechanism shown in broken lines, of coil tong apparatus in accordance with this invention;

FIG. 2 is a side elevational view of the coil tong apparatus of FIG. 1 shown with jaws engaging a coil, and

FIG. 3 is a sectional view taken along the line 33 of FIG. 1.

Referring, to the drawings, and particularly to FIGS. 1 and 3, there is shown coil tong apparatus, indicated generally by the numeral 10, having a box-like frame indicated generally by the numeral 12, which has a top plate 14, bottom plate 16 and

side plates

18, 20.

Each of the

side plates

18, 20 has -a plurality of

slots

22, 24, 26, 28, 30, 32, 34, 36 extending through it. The

slots

22, 24, 26, 28 are disposed in line near the bottom of the side plate (20 in FIG. 1). The pair of

slots

22, 24 are on the left side of the plate, and the pair of

slots

26, 28 are on the right side of the plate. These slots 22-28 are used as a race way for

rollers

38, 40 and 42, 44 for the L-

shaped jaw assemblies

46, 48, respectively.

In the

jaw assemblies

46, 48 the part 50, '52 corresponding to the base of the L has a jaw element 54 or 56 attached to it, the jaw facing in the direction of the up-right member 58 or 60 of the jaw assembly.

Each of the members 58, 60 of the jaw assemblies has a pair of

rollers

38, 40 and 42, 44, respectively, coupled thereto with the rollers being in the

race way slots

22, 24, 26 and 28, respectively, as previously mentioned.

Rack gear elements 62 and 64 are fixedly secured to the upwardly facing sides of the members 58 and 60, respectively. The rack gear elements 62, 64 are of such length and are so disposed that at least a part of the element lies under the slot 30 (or 32) at all times during the operation of the tongs.

Another pair of jaw assemblies 66 and 68, respectively, which are generally L shaped when viewed in side elevation, are disposed with their

base parts

70 and 72, respectively, extending downwardly and their leg parts 74, 76 lie just below the top plate 14 within the frame 12.

Roller assemblies

78 or 80 are coupled to each of the parts 74, 76 and ride in the

race way slots

34, 36 as do the

rollers

38, 40, 42 and 44 in

slots

22, 24, 26, 28.

Rack gear elements 82, 84, similar to the rack gear elements 62 and 64, respectively, are coupled to the side of elements 74 and 76, respectively, which face away from top plate 14. The rack gear elements 82, 84 are so dimensioned and disposed that part of the rack gear elements 82 and 84, respectively, are adjacent to the

slots

30 and 32, respectively, at all times during operation of the tongs.

Jaw elements

86, 88 are secured to the

base parts

70, 72 respectively of the jaw assemblies 66, 68. The jaws '54, 86 and 56, 88, respectively, face each other.

A pinion gear 90 or 92 is disposed between and engages the teeth of the

rack gears

62, 82 and 64, 84, respectively. A shaft 94, 96 extends through and is coupled to the gear 90 or 92, respectively.

Elongated linkage arms 98, 100 are each fixedly coupled to an end of the shaft 96. Similar linkage elements (only element 102 is visible in FIGS. 1 and 2) are fixedly coupled to the shaft 94. The linkage elements above referred to are disposed outside of the frame 12.

An additional pair of elongated linkage elements 104, 106 (in FIG. 3) are pivot-ally coupled to the linkage elements 100, 98 respectively. Similar elongated linkage elements are pivotally coupled with respect to the shaft 94 in a similar manner.

The

linkage elements

104, 106 and their corresponding parts on the other side are all joined together at one end by the coupling pin 110.

A holding element 112 pivotally coupled to the frame 12, is adaped to engage the coupling pin 110 when the jaws of the tongs are open, thus holding the jaws in the open position as the tongs are moved.

The tongs are adapted to be moved by cable means coupled to the tongs through the grab hook 114, for example.

In operation, as shown in FIG. 1, the tongs are moved over the coil 116 to be lifted. With the jaws in position, the holding element 112 is tie-coupled, and the tongs raised by means of the grab hook 114.

As the grab hook 114 is lifted, the links 104, 106 (shown in FIGS. 1 and 2) are raised, also raising the

links

100, 102 which are fixedly coupled to the pinion gears 92, 90, respectively.

Movement of the

links

100, 102 also moves the pinion gears 96, 94, causing movement of the freely movable rack gears which are coupled to the

jaw assemblies

46, 48 and 66, 68.

Each rack gear moves (moving the jaw assembly of which it is a part) until its jaw meets resistance (by contacting the coil 116), then only the other rack gear which is coupled to that particular pinion gear moves. When both jaws contact the coil to be lifted, further rotation only tightens the jaws against the coil. All of the jaw assemblies operate in the same manner.

The length of the

slots

22, 24, 26, 28, 30, 32 34, and

3 36 prevents excessive movement of any of the components of the tongs. A spring 118, coupled between the

jaw assemblies

46 and 48, although not essential to the invention, is-helpful in moving the jaws apart as the coils are to be released.

Because all four jaws of the tongs are independently coupled to the pinion gears 90 or 92, the pressure applied by the jaws is equalized.

Further, because the diameter of the pinion gears 90, 92 is relatively large, a relatively small amount of movement of the

linkage elements

100, 102 results in very substantial movement of the jaws of the tongs. Because of this, the tongs may be operated where low headroom above the coils 116 exists.

What is claimed is:

1. Coil tong apparatus comprising a hollow rigid frame having plate-like side walls, a top plate and a bottom plate, said side walls having an array of similarly disposed and aligned slots near said bottom plate, a pair of aligned slots near said top plate, and a pair of slots disposed in the central part of each said side walls, two pairs of jaw assemblies, each jaw assembly including an L- shaped member having a base part and a leg part, said base part of each member extending below said bottom plate andhaving a jaw affixed thereto, the leg part of one L-shaped member of one pair of jaw assemblies extending adjacent to said bottom plate, roller means coupled be.- tween said leg parts adjacent to said bottom plate and adjacent slots in said array of slots which are near said bottom plate, the leg part of each of the L-shaped members of the other pair of jaw assemblies being disposed adjacent to said top plate, roller means coupled between each of said leg parts of the L-shaped members which are disposed adjacent to said top plate and said aligned slots which are near said top plate, four rack gear elements, one rack gear element being fixedly secured to the leg part of a respective L-shaped member with said gear elements of one pair of jaw assemblies facing the gear elements of the other pair of jaw assemblies, a pair of pinion gears, said pinion gears each being fixedly coupled onto a shaft and also coupled to the rack gear elements of two jaw assemblies which are facing each other,

said shafts each extending through said centrally disposed slots in said side walls, and means coupled to each of said shafts for rotating said pinion gears.

2. Apparatus in accordance with claim 1, wherein said means for rotating said pinion gears comprises a pair of rigid lever arms each fixedly coupled to one of said shafts and each coupled to a common force application means.

3. Apparatus in accordance with claim 1, wherein d tachable means are provided for maintaining said lever arms in a fixed position.

References Cited by the Examiner UNITED STATES PATENTS 2,337,178 12/1943 Breslav 294-86 3,172,694 3/1965 Bradley 294-93 MARVIN A. CHAMPION, Primary Examiner.

G. F. ABRAHAM, Assistant Examiner.

Claims

1. COIL TONG APPARATUS COMPRISING A HOLLOW RIGID FRAME HAVING PLATE-LIKE SIDE WALLS, A TOP PLATE AND A BOTTOM PLATE, SAID SIDE WALLS HAVING AN ARRAY OF SIMILARLY DISPOSED AND ALIGNED SLOTS NEAR SAID BOTTOM PLATE, A PAIR OF ALIGNED SLOTS NEAR SAID TOP PLATE, AND A PAIR OF SLOTS DISPOSED IN THE CENTRAL PART OF EACH SAID SIDE WALLS, TWO PAIRS OF JAW ASSEMBLIES, EACH JAW ASSEMBLY INCLUDING AN LSHAPED MEMBER HAVING A BASE PART AND A LEG PART, SAID BASE PART OF EACH MEMBER EXENDING BELOW SAID BOTTOM PLATE AND HAVING A JAW AFFIXED THERETO, THE LEG PART OF ONE L-SHAPED MEMBER OF ONE PAIR OF JAW ASSEMBLIES EXTENDING ADJACENT TO SAID BOTTOM PLATE, ROLLER MEANS COUPLED BETWEEN SAID LEG PARTS ADJACENT TO SAID BOTTOM PLATE AND ADJACENT SLOTS IN SAID ARRAY OF SLOTS WHICH ARE NEAR SAID BOTTOM PLATE, THE LEG PART OF EACH OF THE L-SHAPED MEMBERS OF THE OTHER PAIR OF JAW ASSEMBLIES BEING DISPOSED ADJACENT TO SAID TOP PLATE, ROLLER MEANS COUPLED BETWEEN EACH OF SAID LEG PARTS OF THE L-SHAPED MEMBERS WHICH ARE DISPOSED ADJACENT TO SAID TOP PLATE AND SAID ALIGNED SLOTS WHCIH ARE NEAR SAID TOP PLATE, FOUR RACK GEAR ELEMENTS, ONE RACK GEAR ELEMENT BEING FIXEDLY SECURED TO THE LEG PART OF A RESPECTIVE L-SHPAED MEMBER WITH SAID GEAR ELEMENTS OF ONE PAIR OF JAW ASSEMBLIES FACING THE GEAR ELEMENTS OF THE OTHER PAIR OF JAW ASSEMBLIES, A PAIR OF PINION GEARS, SAID PINION GEARS EACH BEING FIXEDLY COUPLED ONTO A SHAFT AND ALSO COUPLED TO THE RACK GEAR ELEMENTS OF TWO JAW ASSEMBLIES WHICH ARE FACING EACH OTHER, SAID SHAFTS EACH EXTENDING THROUGH SAID CENTRALLY DISPOSED SLOTS IN SAID WALLS, AND MEANS COUPLED TO EACH OF SAID SHAFTS FOR ROTATING SAID PINION GEARS.