US3330590A

US3330590A - Adjustable stabilized crane tongs

Info

Publication number: US3330590A
Application number: US503573A
Authority: US
Inventors: Sheridan Eric; Graham George Irving
Original assignee: PROVINCIAL ENGINEERING Ltd
Current assignee: PROVINCIAL ENGINEERING Ltd
Priority date: 1965-10-23
Filing date: 1965-10-23
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11

Description

Juli/'11 1967 E. SHERIDAN ETAL 3,330,590

ADJUSTABLE STABILIZED CRANE TONGS Filed Oct. 23, 1965 5 Sheets-Sheet l LllLllll ||||||||I|| lllllll llfllllll l1 ADJUSTABLE STABILIZED CRANE TONGS 5 Sheets-Sheet Filed Oct. 23, 1965 July 11, 1967 E. SHERIDAN ETAL. 3,330,590

ADJUSTABLE STABIL'JIZED CRANE TONGS 5 Sheets-Sheet Filed Oct. 23, 1965 United States Patent O 3,330,590 ADJUSTABLE STABILIZED CRANE TGNGS Eric Sheridan and George Irving Graham, Niagara Falls,

ntario, Canada, assignors to Provincial Engineering Ltd., Niagara Falls, Ontario, Canada, a corporation of Canada Filed (Pct. 23, 1965, Ser. No. 503,573 7 Claims. (Cl. 294-81) This invention or discovery relates to improvements in adjustable stabilized crane tongs, and more particularly to crane tongs of an adjustable nature, highly desirable for lifting various widths and weights of loads, the tongs being most frequently suspended from an overhead crane, hoist, or equivalent mechanism, although the invention may have other uses and purposes as will be apparent to one skilled in the art.

It is an important object of this invention to provide load carrying tongs having jaws adjustable as to spread so as to accommodate loads of various widths, with the jaws interconnected in such manner that one jaw cannot pivot or oscillate in seesaw fashion relatively to the other jaw.

Also an important object of this invention is the provision of a lifting tong arrangement embodying a plurality of pairs of opposed jaws adjustable as to spread to accommodate loads of various widths, the arrangement being such that no single jaw can pivot or oscillate in seesaw fashion relatively to its paired jaw, or relatively to any other jaw of any other pair.

Another important object of this invention is the provision of a lifting tong assembly having two spaced pairs of jaws adjustable as to spread, being so interconnected that the jaws of each pai-r must remain at the same degree of spread as the jaws of the other pair, and no single jaw may pivot or oscillate in a seesaw fashion relatively to any other single jaw of the assembly, and particularly when the tong assembly is moved in a horizontal direction.

A further important desideratum of this invention is the provision of a lift tong assembly embodying at least one pair of opposed jaws adjustable as to spread, the assembly being stabilized in such manner that no single jaw of the assembly can at any time move independently out of its proper coordination with any other single jaw of the assembly.

Also a desideratum of this invention is the provision of a lifting tong assembly having a pair of opposed jaws adjustable as to the spread therebetween, the assembly being stabilized by an interconnecting linkage and cable arrangement effectively preventing one jaw pivoting or oscillating independently of a like movement by the opposed jaw.

While some of the more salient features, characteristics and advantages of the instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational view of an adjustable stabilized crane tong assembly embodying principles of the instant invention, showing the same in operative association with a diagrammatically indicated load;

FIGURE 2 is a fragmentary vertical sectional view taken substantially as indicated by the line II-II of FIGURE 1, looking in the directions of the arrows, and with the suspension hook connection guard removed;

FIGURE 3 is an enlarged fragmentary plan sectional view taken substantially as indicated by the line III-III of FIGURE 1;

FIGURE 4 is an enlarged side elevational view of the structure of FIGURE 1, showing the same in position to accommodate a larger diagrammatically indicated load; and

rice

FIGURE 5 is a diagrammatic view illustrating the reeving of the cables utilized in the structure shown in the other figures.

As shown on the drawings:

The illustrated embodiment of the instant invention comprises a platform 1 reinforced underneath by a crossbeam 2 both of which are welded or equivalently secured to side links 3 3 at opposite sides of the platform, the platform being disposed on top of the side links. Similarly secured to the outer face of each link 3 is a pair of upwardly inclined rests 4 and 5, and secured to each pair of rests is an outer link 6 of the same character as the inner link 3.

In any suitable fashion, the platform 1 supports a drive motor 7, the drive shaft of which is connected to a gear reduction and braking unit 8 of a known character, and a cross-shaft 9 driven by the gear reduction unit extends laterally on both sides thereof, as clearly seen in FIG- URE 3. Each end of the shaft 9 is drivingly connected with a cable drum 10.

Since the illustrated embodiment of the instant invention embodies a pair of lifting jaws on each side of the platform 1, a description of the pair of jaws and associated mechanism on one side of the platform is auto` matically a description of the same structure on the opposite side of the platform.

Through adjacent ends of the fixed links 3 and 6 a fixed pin or stub shaft 11 extends and projects inwardly beyond the link 3. On the inner end of this stub shaft and rotary relatively thereto is a pair of adjacently disposed

sheaves

12 and 13 separated by suitable spacer means 14 and 15. Through the opposite ends of these same fixed

links

3 and 6 is a like fixed pin or stub shaft 16 on the inner projecting end of which is a pair of adjacent sheaves 17 and 18 separated by suitable spacers 19 and 20. Thus, including the platform and fixed

links

3 and 6 on each side thereof, there is formed a generally rectangular frame having a pin or stub shaft carrying a pair of adjacent sheaves at each corner of the frame. All the drive mechanism for actuation of the two pair of tongs shown in the illustrated embodiment is carried on the platform 1.

On each side of the platform 1, a pair of tong levers, generally indicated by

numerals

21 and 22 are pivoted to the stub shafts 11 and 16, respectively. The tong levers of each pai-r are of the same general overall size and each tong lever is shaped in the form of a bellcrank, with the shorter leg thereof functioning as a load gripping jaw.

The tong lever 21 is in the form of a double lever comprising an outer member 21a and an inner member 2lb. A cylindrical piece 23 is disposed between and welded or equivalently secured to these members at the elbow of the lever, and this piece is apertured to pass over the stub shaft 11 and provided more bearing surface on the shaft at this point. As seen best in FIGURES 1 and 2 the double tong lever is provided at its lower end with a gripping jaw 24 of any suitable character. The upper and longer leg of the double tong lever 21 extends at an angle over the platform 1 and is pivotally connected Iby means of a stub shaft 25 to the lower end of a single link 26, the -upper end of this link being pivotally connected to a pin 27 mounted in the lifting head 28. As seen best in FIGURE 2, there are two lifting heads 28-28, one for each pair of ltongs, and these lifting.

heads are connected by a rigid bridge 29. The illustrated embodiment of the instant invention is suspended from two hooks which engage cross-pins 30-30 in the lifting heads.

The stub shaft 25 on the inner end thereof carries a pair of spaced sheaves 31, of the same character as the 33

sheaves

12 and 13 previously described, only one of the sheaves 31 being visible in the drawings.

The tong lever 22 is a single lever of the same shape as the double tong lever 21, but disposed oppositely thereto. The single lever 22 is preferably substantially of a thickness equal to the total thickness of both the members 21a and 2lb of the ydouble tong lever. The lever 22 is provided with gripping jaw means 32 at the lower end thereof, and has external spacers 33-33 welded or equivalently secured thereto at the elbow, providing more bearing surface on the stub shaft 16, as seen best in FIGURE 3. The longer portion of the tong lever 22, above the stub shaft 16, crisscrosses with the like portion of the tong lever 21, as seen in FIGURE 1. The tong lever 22 extends between the members 21a and 2lb of the double tong lever and is pivotally connected at its upper end by way of a stub shaft 34 to a double link generally indicated by numeral 35 and comprising an outer member 35a and an inner member 35h spaced apart sufficiently to accommodate the aforesaid single link 26 therebetween. The double link members 35a and 35b are preferably each of substantially half the thickness of the single link 26. The upper end portions of the double link 35 are both pivotally associated with the aforesaid pivot pin 27. The stub shaft 34 carries a pair of spaced

sheaves

36 and 37 on the inner end thereof which are of the same size and character as the sheaves previously described.

A pair of wire -ropes or cables 3S and 39 are associated with the pair of

tong levers

21 and 22 on each side of the platform 1. With reference to FIGURE 5, where the reeving of a cable is diagrammatically shown, it will be seen that the cable 3S has one end thereof secured to the respective cable drum 10 and is lapped around the drum several times. This cable 38 then passes over the sheave 35 on the stub shaft 34, then descends and passes around the sheave 12 on the stub shaft 11, then rises and passes over the sheave 37 on the stub shaft 34, and then again descends and passes around the sheave 13 on the stub shaft 11, and then rises again to the stub shaft 34 where the other end of the cable is anchored to that stub shaft as indicated at 40. The cable 39 is similarly reeved around the sheaves on the

stub shafts

16 and 25, but the end of this cable 39 is anchored to the `cable drum 10 at a point diametrally opposite to the anchor point of the cable 3S. Similarly, cables are reeved around the pulleys associated with the tong levers on the opposite side of the platform 1.

In operation, the instant invention is simple and positive. It is simply necessary to position the tongs over a load, actuate the motor 7 to spread the tongs by way of the cables sufficiently for the tongs to be lowered over the load, and then the motor is operated in the opposite direction to bring the

jaws

24 and 32 toward each other `gripping the load therebetween. In FIGURE 1 we have illustrated the use of the tongs in connection with the elevation of a load 41 that is relatively narrow, while in FIGURE 5 the tongs are shown fully expanded to accommodate a load 42 of much greater width. In this second figure, it will be seen that the upper portion of each tong lever seats upon the respective rest 4 or 5 carried by the tong frame when the tongs are in fully expanded condition.

It will be especially noted that in use, absolute stability of the tong jaws relatively to each other is provided. Both cable drums 10-10 are driven in the same direction and at the same speed by the drive shaft 9 so the pair of tongs on one side of the frame must operate in unison with the pair of tongs on the other side of the frame. The cables connected to the drums 19-1@ effectively prevent any tong lever from moving without a corresponding movement of every other tong lever. This is especially advantageous when the tongs are being transferred empty in search of a new load, in which event in most cases the lifting head of the tongs will be travelling substantially horizontally. The extremely hazardous condition of one tong lever oscillating in a seesaw manner relatively to the other tong lever or levers, which was quite common heretofore, has been completely eliminated. Each tong jaw has and maintains its proper relationship to each of the `other tong levers at all times, and workmen are not subject to the danger incurred in endeavoring to manually adjust an individual tong lever at the time a load is engaged.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention,

We claim as our invention:

1. In a crane tong assembly,

a generally rectangular frame,

a stub shaft adjacent each corner of said frame,

a tong lever pivoted to each said stub shaft,

sheave means on each said stub shaft,

sheave means adjacent an end of each said tong lever,

drive means on said frame,

Opposed cable drums driven in unison by said drive means, and

separate cables on said drums each being reeved over sheave means on one of said stub shafts and the sheave means carried by the tong lever pivoted to the other stub shaft on the same side of the frame,

whereby one tong lever cannot individually oscillate relatively to any other tong lever.

2. In a crane tong assembly,

a generally rectangular frame,

a stub shaft adjacent each corner of said frame,

a tong lever pivoted to each said stub shaft,

sheave means on each said stub shaft,

sheave means adjacent an end of each said tong lever,

drive means on said frame,

opposed cable drums driven in unison by said drive means, and

separate cables on said drums each being reeved over certain of said sheave means different from those of any other cable in a manner to prevent movement of any tong lever individually and relatively to any other tong lever.

3. In a crane tong assembly,

frame means,

a pair of opposed tong levers pivoted to said frame means at opposite points,

a load gripping jaw on one end of each said tong lever,

sheave means connected to the other end of each said lever,

sheave means on said frame means adjacent the pivot point of each lever,

drive means on said frame means,

a cable drum actuated by said drive means,

a pair of cables connected to said drum each reeved over the sheave means on the frame means adjacent the pivot point of one lever and the sheave means connected to said other end of the other lever,

whereby said levers are actuated in unison without individual movement of one relatively to the other.

4. In a crane tong assembly,

frame means,

a pair of opposed tong levers pivoted to said frame means at opposite points,

a load gripping jaw on one end of each said tong lever,

sheave means connected to the other end of each said lever,

sheave means on said frame means adjacent the pivot point of each lever,

drive means on said frame means,

a cable drum actuated by said drive means,

a pair of cables connected to said drum at diametrally opposed points each reeved about the sheave means on the frame means adjacent the pivot point of one 3,330,590 6 lever and the sheave means connected to said other one of said levers being a double lever With spaced inend of the other lever, ner and outer members, whereby said cables actuate said levers to adjust the width the other lever being a single lever with its longer leg between the jaws thereof and also prevent individual inextending between the spaced members of the longer dependent movement of one lever relatively t0 the other. 5 leg of the double lever,

5. In a crane tong assembly, a drive motor on said frame means, frame means, a cable drum on said frame means operated by said a pair of opposed tong levers pivoted to said frame motor,

means at opposite points, sheave means connected to said frame means adjacent a load gripping jaw on one end of each said tong lever, the elbow of each said lever, sheave means connected to the other end of each said sheave means adjacent the upper end of the longer leg lever,

sheave means on said frame means adjacent the pivot point of each lever,

drive means on said frame means,

a cable drum actuated by said drive means,

a pair of cables connected to said drum at diametrally 0f each said lever, and

a pair of cables connected to said drum and each reeved over the sheave means at the elbow of one lever and the sheave means adjacent the upper end of the longer leg of the other lever.

7. A crane tong assembly as recited in claim 6, whereopposed points each reeved about the sheave means on the frame means adjacent the pivot point of one lever and the sheave means connected to said other end of the other lever, a lifting head, and a pair of links each pivotally connecting said other end of one lever with said liftinghead, whereby one of said levers is prevented from oscillating relatively to the other lever.

6. In a crane tong assembly, frame means,

in all the recited structure in addition to said frame means and except for said motor is disposed adjacent one side 20 of said frame means, and including a duplicate of said structure adjacent the opposite side of said frame means, both cable drums being driven in unison by said drive motor.

References Cited UNITED STATES PATENTS 1,962,700 6/1934 Allard 294-112 `a pair of confronting L-shaped tong levers pivoted lat 2 903 294 9/1959 Shook 294 88 their elbows to said frame means at opposed points 3021169 2/1962 Harry "294*118 X thereon, the shorter leg of each member depending from its connection with said frame means to engage a load, the longer legs of said levers being disposed in crisscrossed relationship above said frame means,

GERALD M. FORLENZA, Primary Examiner. G. F. ABRAHAM, Assistant Examiner.

Claims

1. IN A CRANE TONG ASSEMBLY, A GENERALLY RECTANGULAR FRAME, A STUB SHAFT ADJACENT EACH CORNER OF SAID FRAME, A TONG LEVER PIVOTED TO EACH SAID STUB SHAFT, SHEAVE MEANS ON EACH SAID STUB SHAFT, SHEAVE MEANS ADJACENT AN END OF EACH SAID TONG LEVER, DRIVE MEANS ON SAID FRAME, OPPOSED CABLE DRUMS DRIVEN IN UNISON BY SAID DRIVE MEANS, AND SEPARATE CABLES ON SAID DRUMS EACH BEING REEVED OVER SHEAVE MEANS ON ONE OF SAID STUB SHAFTS AND THE SHEAVE MEANS CARRIED BY THE TONG LEVER PIVOTED TO THE OTHER STUB SHAFT ON THE SAME SIDE OF THE FRAME, WHEREBY ONE TONG LEVER CANNOT INDIVIDUALLY OSCILLATE RELATIVELY TO ANY OTHER TONG LEVER