US2520815A - Lifting tongs - Google Patents

Description

Aug. 29, 1950 E. Y. SHABOO 2,520,315

LIFTING TONGS Filed June 12, 1946 2 Sheets-Sheet 1 IN VEN T OR.

ATTD R N EYS Patented Aug. 29, 1950 OFFICE 2,520,815 rl'm'rme Toms Edward Y. Shaboo, Phoenix, Arie. Application June 12, 1946, Serial no. 676,261!

Claims. (01. 294M116) This invention relates to cable type lifting tongs that are particularly adapted for lifting or handling bombs, shells, pipe or similar cylindrical objects.

An object of the invention is to provide a device that when used with suchcylindrical 'objects will by its own weight open the jaws thereof to engage the object past the 180 degree angle thereof, and upon lifting thereof will firmly grasp the object, lock the jaws about the object and retain the jaws in that'poslti'onuntil the "object is again placed on a supporting surface, at which time the jaws will release themselves from the object to rest the object on the surface.

The clamping action is automatic, and will not be released until the weight of the object is re moved from the jaws.

With the above and other objects and advantages in view, the invention consists of the novel details of construction, arrangement and com-- bination of parts more fully hereinafter described, claimed and illustrated in the accompanying drawings in which:

Figure 1 is an elevational view of an embodiment of the invention as applied to a circular object shown in dotted line;

Figure 2 is a top plan view thereof;

Figure 3 is a side View thereof;

Figure 4 is a view of the opposite side;

Figure 5 is a sectional view on the line 55 of Figure 1;

Figure 6 is an elevational view of one jaw, and

Figure '7 is an elevational view of the other aw.

Referring more in detail to the drawings, the reference numerals Ill and I2 designate the individuals of a pair of lift arms which, together with their pivot, are herein distinguished as the hoist component of the lifting tongs. Said arms are apertured at M at their outer ends for connection to hoisting means such as a cable IE or the like as shown in dotted lines in Fig. 1. The inner ends of the lift arms comprise cam ends which are adapted to make pressure contact with the remainder of the structure, herein identified as the grapple component.

The latter comprises a jaw I8 consisting of parallel portions 20, 22 which are rigidly con nected at the lower end in that relationship by an enlarged foot 28, the inner face 30 of which is curved because of matching the contour of the respective jaw. Each of the portions of the jaw 18 has an upstanding pivot lug 24 at its upper end. A pin 26 pivotally connects the arms [0, I2 to the lugs, said arms being in the symmetrically crossed relationship" show The infief and can": ends or the arms engage tne'acijacent bearing plane of a second and ccmpfemental jaw 32, it being that the pomtsflei contact are spaced equidistantl from the bearin pri 26 and e ually" from the central, verti'cal line 0' lift. r I

. A hinge pin 3' revifes anomcenter connectien er the jaw 32 with tnejaw t8, the aminestion being well one side of the line of lift thereby leaving unlnterru ted the previcusl-y mentioned bearing "plane was which the term ends of the lifting arms engage. The jaw 32 is provided at its lower end with an enlarged foot 36, the inner curved face 38 comprises a continuation of the contour of the respective jaw.

During the operation of the tongs, the jaws I8, 32 are positioned on opposite sides of the object 40, and as the cable I6 is tightened, the lift arms l0 and I2 exert downward pressure on the jaw 32 and upward pressure on the pivot pin 26, thereby to close the jaws and cause them to firmly engage the object. Thus as long as the strain remains on the lift arms, the jaws will firmly grasp the object for the lifting thereof, but when the object is placed on a supporting surface, the grip of the jaws will be loosened in readiness for release therefrom. The jaws grasping the object below its degree angle and the inner faces of the feet being curved will prevent the object from being disengaged from the jaws until the strain is released from the lift arms.

It is believed that from the foregoing description the operation and construction of the tongs will be apparent to those skilled in the art, and it is to be understood that changes in the details of construction, arrangement and combination of parts may be resorted to, provided they fall within the spirit of the invention and the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Lifting tongs comprising complemental jaws, hinged together in off-center relationship providing for one of the jaws an uninterrupted bearing plane medially of the ends of the jaws, at least one pivot lug upstanding from the other jaw adjacent to said bearing plane, a pair of lift arms having outer ends for connection with hoisting means and inner ends to function as cams, and a, pin pivotally connecting the arms to the lug in crossed relationship, with the cam ends in pressure contact with the bearing plane equidistantly from the pivot pin.

2. Lifting tongs comprising interfittedly assembled jaws, hinged together in off-center relationship in respect to the line of lift and providing for one of the jaws an uninterrupted bearing plane medially of the ends of the jaws, at least one pivot lug upstanding from the other jaw adjacent to said bearing plane centrally of and on said line of lift of the assembly, a pair of lift arms having outer ends for connection with hoisting'means and inner ends to functionas cams, and a pin pivotally connecting'the arms to the lug in crossed relationship, with the cam ends in pressure contact with the bearing plane at points spaced equally from the line of lift.

3. Lifting tongs comprising a pair of camended lift arms, a pivot pin connecting the arms' near'the cam ends and in crossed relationship, the other ends of the arms being connectible with hoisting means, a pair of complemental jaws of which one jaw is connected to and depends from the. pivot'pin, and a hinge pin by which; the other jaw is connected to said one jaw,,off-center in relationship to the pivot pin and tomunderlie the cam ends of the lift arms, 1 t

4. Lifting tongs comprising a jaw, including parallel arcuate portions having pivot; lugs; a pair of lift arms, a pivot pin by which thejarms are tumably supported in :symmetrical]y;-arranged crossed relationship. between the, lugs, the

ends; of the arms nearest to the jaw constituting cam ends, and a complemental-arcuate;jaw operable between said; parallel portions, being REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I Name Date 126,818 Lindsay May 14, 1872 2,342,506 Wrobbel Feb, 22, 1944 2,352,017 Scharpenberg et a1. V c z June 20, 1944 v FOREIGN'PATENTS Number Country Date Norway Feb. 6, 1939

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