US2347922A - Hoisting tong - Google Patents

Description

.L. NELSON HOISTING TONG May 2, 1944.

Filed April 12, 1943 Patented May 2, 1944 PATENT OFFlCE 2 Claims.

This invention relates to a hoisting tong.

An object of the invention is to provide a tone of the character described specially adapted for lifting heavy metal plates, beams and the like.

Another object of the invention is to provide a tong having opposing fixed jaws provided with downwardly converging faces on which are mounted wedge shaped slips whose inner sides are formed with teeth to engage the load between the slips.

A further object is to provide, in a tong, releasable means for automatically locking the slips in engagement with the load to prevent the unintentional release of the load.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation, and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawing wherein:

Figure 1 shows a side view of the tong partly in section.

Figure 2 shows an edge view.

Figure 3 shows a fragmentary cross sectional view taken on the line 3-3 of Figure 1.

Figure 4 illustrates the ratchet faces of the locking dogs employed and Figure 5 illustrates one application of the tong to the load.

Referring now more particularly to the drawing wherein like numerals of reference designate the same parts in each of the'flgures, the numerals I, I refer to opposing fixed jaws which are formed integrally, at one end, to the eye 2. These fixed -aws have the faces 3, 3 which converge toward the free ends of the jaws.

In the inner sides of the jaws I are the longitudinal dove tailed grooves 4. 4 which extend a the full length of the faces 3. There are the,

wedge shaped slips 5, 5 which are dove tailed into the grooves. The inner sides of the slips are parallel and toothed to engage and grip the plate 6, or other load, between them.

Each jaw 5 has the projecting side pins 1, 'l

' elevation of the tong the slips 5 will move downwardly along the faces 3 and inwardly into gripping relation with the load; or a pair of tongs may be engaged with the plate as shown in Figure 5 and connected to the ends of the bridle II) which, in turn, may be lifted by the cable 9.

Provision has been made for locking the slips in engagement with the load to prevent premature release of the load. For this purpose the outer side of each slip'is provided with the upwardly pitched ratchet teeth, II. Each fixed jaw I is provided with abore I2 to receive a cylindrical dog I3. The inner end face of this dog has transverse ratchet teeth pitched oppositely from that of the pitch of the corresponding teeth ll.

Screwed into the outer end of the bore I2 there is a gland 14 having the inside longitudinal grooves I5. Each dog I3 is attached to an outwardly extended shank I5 which extends out through said gland and whose outer end is formed into a grip H. The shank has a cross key I8 whose ends extend into the grooves I5.

Located within the bore I2 and surrounding the shank and interposed between the gland I4 and the dog I3 there is a strong coil spring I 9.

As the tong is applied to the work the slips 5 will move upwardly along the face 3 and outwardly to permit the plate 6, or beam, to readily enter between the slips. While applying the tong to the work the dogs I3 should be pulled outwardly until the cross keys I8 are released from the grooves I5 and then turned so that the ends of the cross keys will engage the outer ends of th bushings I4. The dogs will thus-be held retracted with the teeth of the dogs out of engage ment with the teeth I I. slips 5 to move freely. When the plate or beam has been inserted between the slips the shanks I6 should be turned to align the cross keys with the grooves I5 and the springs I9 will move the dogs inwardly into active position. Upon an upward pull of the cable 9 the slips 5 will move downwardly along the faces 3 and inwardly into engagement with the load, the teeth II ratcheting past the teeth of the dogs I3 and said slips will be locked in said position by said, dogs so that the tong will not accidently or prematurely release the load.

It will be noted from an inspection of Figure 4 that the teeth of one dog I3 are staggered with respect to the teeth of the other dog.. This has been done to insure that at least one dog will engage with the teeth of the corresponding slip. Otherwise it might happen that the crests of the teeth of both dogs might rest on the crests of the This will permit the- 2 assmaa oorresponding'teeth ll thus allowing a sumcient release movement to both slips to permit release oi the load. I! either of the slips is locked against movement the other slip. even though not locked by its dog. will be held against release movement by the engagement of its teeth against the load.

The drawing and description are illustrative merely while the broad principle of the invention will be defined by the appended claims.

What I claim is:

1. A hoisting tong comprising a pair of spaced .Jaws anchored together at one end and having their. other ends free, said jaws having inside faces whieh'converge toward said free ends, wedge shaped slips mounted on said races and having dovetailed connections therewith and mounted to move into gripping relation with a load between the slips, one of said jaws being gland, a cross key on the shank whose end extends into the groove, a yieldable member in the bore normally-holding the dog in engagement with the corresponding slip, said key being engageable with the outer end of the gland. when the shank is pulled outwardly and turned, and forming means for locking the dog disengaged from the slip.

2. A hoisting tong comprising a pair 0! spaced jaws anchored together at one end and having their other ends free, said Jaws having inside faces which converge toward said free ends,

'dogs mounted on the Jaws and having ratchet teeth, yieldable means normally holding the teeth of the dogs in engagement with the teeth of the slips, the teeth on one side of the tong pmvidedwithaboreagland securedinthe outer 20 being staggered with respect to the teeth on end of the bore and having an inside longitudinal groove. a dog in said bore having an outwardly extended shank which extends through the the other side thereof.

LEE NELSON.

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