US1733248A - Automatic gripping tongs - Google Patents

Description

Oct. 29, 1929.

E. C. WILSQN ET AL AUTOMATIC GRIPPING TONGS Filed Feb. 20, 1926 2 Sheets-Sheet l Oct; 29, 1929. E. c. WILSON El AL.

AUTOMATIC GRIPPING TONGS Filed Feb. 20. 1926 2 Sheets-Sheet 2 rammed Oct. 29, 1929 warren STATES PATENT oFFicE ELIHU C. WILSON AND GEORGE WOOLW Y, OF LOS ANGELES, CALIFORNIA, ASSIGNORS, BY DIRECT AND MESNE ASSIGNlvEENTEi, TO BYRON JACKSON PUT/[P 00., OF WEST BERKELEY, CALIFORNIA, A CORPORATION OF DELAWARE AUTOMATIC GRIPPING TONGS Application filed February 20, 1926. Serial No. 89,533.

This invention pertains generally to wrenches or tongs such as are used on pipe and other cylindrical work. It is applicable with particular advantage to tongs used on well pipe, rotary drill pipe and the like, and we will therefore describe it as so applied. How ever, this is in no way to be considered as limitative or restrictive on the invention, considered in its broader aspects.

it is a characteristic of tongs that their work encircling members, necessarily it somewhat loosely about the work when first applied thereto. It requires application of added force to take up this looseness and thereby move the members into work gripping position. The means for taking up this looseness depends upon the particular type of tong, for instance, movement of the operating handle or independent movement of jaw carried dies. So far as we are aware, it has always required independent movement on the part of the operator to accomplish this movement into gripping position. It is therefore among the objects of the present invention to provide automatically acting means to accomplish such movement, the action occur ring immediately after the tongs have been applied to the pipe.

In our invention, not only are the work gripping elements automatically moved to gripping position but they are held in such position until wilfully released. The advantages of these features may best be pomted out by reference to a particular type of tongs, though this is not to be considered as in any way intimating that the invention is limited to embodiment in this type. Take for example the self-closing tongs shown and described in the co-pending application of Robert Adams, filed October 28, 1924, Serial No. 746,257, or the United States Letters Patent No. 1,561,963 on tongs, issued to E. C. Wilson (one of the applicants hereof) on November 17, 1925; which tongs, for conven ience, are illustrated in the instant application.

Here are shown tongs embodying an operating handle to which are independently pivoted two sets of jaw segments, one or more of the segments having dies, there being a spring latch for connecting the freeends of the segment sets after they have been brought about the work. In order that the latch may engage when said free ends are brought together, there is necessarily a degree of looseness in the fit of the jaw segments about the work, the aw dies therefore being out of operating engagement with the work. If no further move is made by the operator, and he then releases his hold on the tongs handle, there is nothing to prevent the tongs from sliding down the work (assuming that the work is in the nature of a vertically extending pipe) or to prevent the tongs from rotating until the handle strikes an obstruction or lies directly beneath the work (assuming that the work is in the nature of a horizontally extending pipe).

In order to move the jaws into gripping position (or sink the dies into the work) the operator must swing the operating handle in a predetermined direction, which swinging movement, due to the offset pivotal arrangement of the segments, moves the jaws into work gripping position or sinks the dies into the work, and, in order to do this, the opera tor must by some applied force or manipulationas by holding the latched jaws with one hand while moving the handle with the otherkeep the jaws from moving bodily with the handle during the jaw contracting movement of the handle. If the operator at any time relieves the strain on the operating handle, there is nothing to prevent the jaws from again loosening from the work, with the objectionable results mentioned above. Furthermore, in ratcheting the tongs, at the start of each work stroke there is necessarily a considerable degree of lost motion in moving the jaws back into work gripping position. We overcome these objectionable features by introducing a spring in the assembly, this spring being so arranged that, with the aws latched together, it constantly exerts a tend ency to swin the operating lever in the direction necessary to constrict the jaws about the pipe and move them into gripping relation thereto. The operator may then entirely release his hold on the operating handle, the spring putting such a strain'on the jaws that lUO they are maintained in gripping position. When the tongs are backed up during ratcheting operations, the spring acts automatically to return the jaws to or keep them in gripping position.

It is not to be inferred from the above that in all situations must the spring be connected to the operating handle in a manner to swing the latter in the manner described, for in tongs other than that of the type described, the spring may have no direct connection with the handle whatsoever. Broadly considered the spring may be considered as means to move the jaws into gripping position, or to take up the looseness in the tongs assembly and put such astrain on the jaws as o move them into and retain them in gripping positlon.

In connection with tongs of the type illustrated in the drawings (and it may be true of other type tongs) the springs serves an other purpose inasmuch as, when: the latch is released, the spring serves to throw one or more of the aws to open position.

The above features all tend to increase the general efficiency of the tongs, as will be readily understood by those acquainted with the art.

Other objects and novel features of the invention will he made apparent in the following detailed description, reference being made to the accompanying drawings, in which:

Fig. 1 is a plan view, partly in broken away section, of tongs embodying our invention, showing the position of parts while the tongs are being placed on and closed about a p'pe;

Fig. 2 is a View similar to Fig. 1, but showing the tongs closed about such a pipe;

Fig. 3 is a detached, fragmentary end elevation of the tongs handle and associated parts as viewed from the position of arrow 3 in Fig. 1;

Fig. 4 shows a variational embodiment of the invention;

Fig. 5 is a View similar to Fig. 2 but showing. a different type of stop between the tongs jaws;

Fig. 6 is a fragmentary view of the tongs illustrated in Figs. 1 and 2 but showing a different spring arrangement; and

Fig. 7 is a section, partly in elevation, on line 77 of Fig. 6.

In the drawings we have shown a handle 10, of any convenient lengtlnthe forward end 11. of which is recessed, as clearly shown at 16 in Fig. Spaced pivot pins 12 and 13 are carried by handle 10. the first nai'ncd pin extending through the bifurcated end. Pin-i otally arranged on said pins are pipe encircling. and gripping elements which are, in this specific illustrative embodiment of our invention, eaclr shown as being made up of two segments or aws. Thus, the two inner segments: or jaws 14; and 15 are pivoted directly to the handle on pins 18 and 12, respectively; and the two outer jaws or segments 16 and 17 are pivotally connected by pins 18 and 19 to the outer ends of inner aws l l and 15, respectively. Preferably, we provide replaceable dies for one or more of the jaws, for instance, we show die 14; secured to jaw 14; by bolt 14: Swinging of handle 10, as will be eadily understood, in the direction of the arrows, moves pins 12 and 13 relatively about each other in a clockwise direction and causes the segments to constrict about work such as pipe P, for instance. Movement of the handle in the opposite direction backs off the segments or loosens them about the pipe.

Segment 16 carries at its outer end a pivoted latch member 20 which has a latching shoulder 21 adapted to drop over and engage one of a plurality of lug shoulders, which in this case are shown to be two in number, 22 and 23, spaced apart from each other in a direction generally circumferential of the tongs or pipe, the spacing being suitable to adapt the tongs to dili'erent sizes of pipe, or, for instance, to a given size pipe and its collar. Latch 20 swings on pivot 24 and is pressed by spring 25 so it is constantly urged inwardly against the latch lug, the inner face 26 of the latch head being so formed that it will ride out and over the outer surfaces 2'? of the latch lug as the tongs are closed about the pipe. Jaw 17 is provided wit-l1 a handle 30, the purpose of which will appear presently.

It will be readily understood from a consideration of the drawings how the latch will automatically engage when the segments are closed about a pipe, and how the latch will engage selectively with either shoulder 22 or 23, depending upon the size of the pipe being closed upon.

.1 aw 14; has a stop shoulder 410 that is adapted to contact with handle 10 when said handle is thrown to the position of Fig. 1. This jaw also has a stop shoulder 41 with which lug 12 on segment 16 is adapted to contact when segment 16 is in the position of Fig. 1. It is not essential that the stops bet-ween. jaws 14, 1.6 and handle 10 be of the shoulder type just described. For instance, in Fig. 5 (wherein all parts other than the stop shoulders are similar to corresponding parts in Figs. 1 and 2 and are therefore not described or numbered) the steps may be yieldable to a certain degree, a coil spring 10 functioning as the stop between handle 10 and jaw 1 1, and coil spring 11 on pivot 18 functioning as a yieldable stop between jaws 14 and. 16 The yield able stops exert a constant tendency to move the jaws into constricted position about the pipe, and yield to allow opening movement thereof, but limit the extent of such opening movement.

Jaw 15 has a stop shoulder a3 adapted to ie engaged by a shoulder 1-1 on jaw 17 when said last named jaw is thrown to open position. Jaw 15 has a stop shoulder 45 adapted to engage handle when said jaw is in the open position of Fig. 1. On pivot pin 12 and positioned in the recess 46 in the end of the handle is a coil spring 47. One end 48 of this spring engages handle 10 while the other end 49 engages jaw 15. This spring is arranged to urge jaw 15 constantly to its open position, and when the jaws are open it yieldably maintains shoulder in contact with handle 10. Now it will presently be made clear that it is not essential to the invention that spring 47 be of the type shown nor arranged in the manner illustrated, but we will first describe the operation of the device with the spring employed in the manner above described.

With the tongs in the condition shown in Fig. 1, the operator grasps handle 10 with one hand and handle 30 with the other hand. Now the exact method of handling the tongs in applying them is not important, for they may be applied by first placing either set of jaws against the pipe and moving the other set up to and about the pipe. For purposes of description, it will be assumed that the operator moves jaws 14, 16 into contact with pipe P. To do this the operator has to swing handle 10 around against stop 40; and then holding the handle in that position against swinging in the direction indicated by the arrows, he then pushes handle 80 away from him, against the action of spring 47; that is, he pushes handle 30 to swing jaws 17 and 15 in the direction indicated by the arrow in Fig. 1 to close those jaws down on the pipe. It is evident that the jaws are thus moved about the pipe and that the latching lug passes under latch shoulder 21,the latter finally dropping over shoulder 23 as illustrated in Fig. 2.

For the time being, assume that spring 47 be omitted from the assembly. WVhen the parts reach the position just described (closed but'loose on the pipe) the four segments would necessarily be somewhat loose upon the pipe, but the amount of looseness I or back 01f allowed segment 16 by the interaction of shoulders 41, 42 is not great enough to permit this segment to back off sufficiently to allow latch shoulder 21 to drop oft. lug shoulder 23. The described jaw looseness is, of course, necessary in order that thetongs may be applied to the pipe with the assurance that latch shoulder 21 may drop over lug shoulder 23. In order to constrict the jaws tart 161 and thus draw them, or die 14, into gripping relation to the pipe, handle 10 must be swung (relative to the jaws) in the direction. of the arrows, this handle movement causing such further jaw constriction or takin -up of looseness by virtue of the offsetting 0t pivots 12, 18, such pivots moving relatively about one another in a clockwise direction, as viewed in Fig. 2. If the jaws be not so further constricted, or if the strain on handle 10 be relieved there is nothing (in the absence of spring 47) to keep the tongs from free movement about or along the pipe.

However, with spring 47 in place, the jaw looseness is taken up automatically as soon as the latch operatively engages the latch lug and the manual forces are relieved, and the spring maintains the jaws in gripping position until the latch is deliberately released or until handle 10 is swung in the direction opposite that of the arrows. In the latter event, as soon as the back off strain on handle 10 is relieved (assuming now that the latch is still holding) spring 47 automatically returns the jaws to or keeps them in gripping position. A consideration of Fig. 2, remembering that spring 47 is under considerable compression and tends to move pivot 13 in a clockwise direction about pivot 12 (or in other words, to swing handle 10 in a clockwise direction) will make it apparent how spring 47 functions in this capacity. The advantage of this feature need not be discussed, for they are self-evident.

Although we have explained the action so far in terms of absolute handle or jaw movements, on the assumption that one or the other is stationary while the other or the one moves or is manually moved, yet it will readily be seen that the effective movements are purely relative. For instance, after the jaws are closed and latched, but still loose about the pipe, when hand pressures are removed from handles 10 and 30 the action of spring 47 is to move the jaws and handle relatively, to constrict the jaws. It a hand is still kept on handle 30 to hold the jaw as a whole from rotating about the pipe then spring 47 throws handle 10 around in the arrow indicated direction to constrict the jaws. If, on the other hand, handle 30 is released and the hand still kept on handle 10 to hold it more or less stationary, the action of spring 47 is to move the jaws with reference to the handle. This the spring may do without moving handle 10 at all if pipe P is movable of course, it pipe P is immovable the final action of spring 47 in any case is to swing handle 10 around.

And another illustration of the fact that the movements are entirely relative lies in another practical method of applying the tongs to the pipe. Instead of first putting jaws 14, 16 against the pipe let us suppose the operator to be standing between handles 10 and 30 and that he first applies jaw 15 against the pipe. Then by pushing both handles away from him he closes jaw 17 against the pipe and throws jaws 14, 16 around the other side of the pipe, the latch then operating as before. Then a release of either handle, or both, allows spring 47 to constrict the jaws about the pipe as before described.

hen member 20 is wilfully unlatched from the latch lug, spring t? acts to throw jaw 15 back to the position of Fig. 1, thus ell'ecting a quick opening of one side of the tongs, an advantageous feature which will be readily understood.

In Fig. 4 is shown a variation in which all parts 01' the tongs are substantially the same as in Fig. 1, except that a spring 4 1, extending between handle 10 and jaw 17 is substituted for spring N. A convenient point of spring atachment to jaw 17 is handle as illustrated at 30". It will be seen tha spring at?" has a normal tendency to swing a jaw 17 so shoulders 43 and d4 engage and thereby swing jaw 15 in a countercloclnvi'se direction until shoulder 45 engages handle 10. in other words spring 47 normally tends to hold both jaws 15 and 17 in full open position. Vi hen the jaws arel'atched about the pipe,spring 4:7 tends to swing'pivots l2 and 13in a clockwise direction about each other and thereby tends to move the aws into and yield ably maintain them in pipe gripping position.

In Figs. 6 and 7, we have illustrated the us'eot a spring li which tunctio in a manner similar to spring at? but arranged somewhat diiierently. Spring l? has a portion 50 which extends across the side of handle lfOHsai'd edge having a shoulder 51 against which said portion bears. 'lhc coiled portions 52 of the spring are on pin 12 at opposite sides of jaw 15*, the tree ends 53 of the spring engaging shoulder 54: on said aw. It will be evident from the draw ings that spring 47 functions in a manner similar to that described in connection with spring 47.

it is not to be inferred that we have at tempted an exhaustive showing of the dirfcrent types of springs and spring arrangements which may bc-employcd for the purpose set forth, for the scve -a'l showings are merely illustrative and are not to be considered as limitative orrestrictive on the broader claims appended hereto.

We claim:

1. In a pipe tongs, a handle, two elements adapted to encircle a pipe, means adapted to detachably connect said elements and hold them in pipe encircling position, said elements being pivoted to the handle at separated pivotal points so that oscillation of the handle, when the elements are connected, moves the element to and from each other to close them upon the pipe or baclrthem oi? the pipe, means acting between the handle and one element to limit backingcff motion oi. the handle relatively tothat element,- and resilient means acting between the handle and the other element tending to move that element and the handle relatively to constrict the elements about the pipe.

2. In a pipe tongs, a handle, two elements adapted to encircle a pipe, said elements being respectively pivoted at one end to the handle at separated pivotal points so that oscillation of the handle, when the elements are connected moves the elements to and from each other to close them on the pipe or back them cit the pipe, means detachably to connect the free ends of the elements and hold them in pipe encircling position means acting between the handle and one el ment to limit backing-cit motion of the handle relatively to that element, and resilient means acting between the handle and the other element tending to move the handle relatively to that element to eonstrict the elements about the pipe and tending to swing the last mentioned element about its pivot to open position when the connecting means is detached.

3. in a pipe tongs, a handle, two pipe encircling elements pivoted to the handle at spaced pivot points so that swinging movement of the handle in one direction with 1% rence to the elements causes constriction or the elements about a pipe, one of the elements when nnlatched having an opening movement about its handle pivot in a relative direction opposite to the swinging movement ot the handle for constriction of the elements, and means acting between the handle and said clement tending to move them relatively in said named directions.

l. In a pipe tongs, a handle, two pipe encircling elements pivoted to the handle at spaced pivot points so that swinging movement of the handle in one direction with reference to the elements causes constriction of the elements about a pine, one of the ele ments when unlatched having an opening movement about its handle pivot in a relatlVGJllI'GCiJlOIl opposite to the swinging movement of the handle for constriction of the elements, and a spring acting between the handle and said element tending to move them relatively in said named directions.

In witness that we claim the foregoing we have hereunto subscribed our names this flth day of January, 1926.

ELIHU C. WILSON. GEORGE WOOLVVAY.

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