US2989880A

US2989880A - Power tongs

Info

Publication number: US2989880A
Application number: US746543A
Authority: US
Inventors: Earl D Hesser; Walter W Short
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-07-03
Filing date: 1958-07-03
Publication date: 1961-06-27
Anticipated expiration: 1978-06-27

Description

June 27, 1961 45555 ETAL 2,989,880

POWER TONGS Filed July 5, 195a s Sheets-Sheet 1 INVENTORS 1 far/ 17. HeJJer W l /fer l V. JfiO/Z June 27, 1961 HESSER ET AL 2,989,880

POWER TONGS Filed July 5, 1958 3 Sheets-Sheet 2 Wo/Zer W. 5/20 27 INVENTORJ ATTOR/VEVJ June 27, 1961 HESSER ETAL 2,989,880

POWER oms Filed July 3, 1958 I5 Sheets-Sheet 3 INVENTORS United States PatentO 2,989,880 POWER TONGS Earl D. Hesser, 5441 Kleberg, and Walter W. Short, 1939 Norfolk, both of Houston, Tex. Filed July 3, 1958, Ser. No. 746,543 3 Claims. (CI. 81-53) are fixed to the carrier, while a third is mounted thereon for swinging between an operative position for gripping the pipe intermediate the fixed jaws and a retracted position to permit passage of the pipe through a side opening in the carrier.

The carrier for the jaws is rotatably mounted within a ring which is, in turn, rotatably mounted within a frame. As the ring is rotated with respect to the carrier, parts thereon are engageable with the third jaw for swinging it between operative and retracted positions. However, as can be seen from the drawings of the aforementioned patent, one of the fixed jaws is disposed outwardly of a line passing through the axis of the center opening and perpendicular to the side opening of the carrier, thereby limiting the maximum size of pipe which the tongs can accommodate.

Furthermore, the location of these jaws, including the pivotal axis of the swinging jaw, is critical. Thus, if the fixed jaws were to be shifted to positions in which both were disposed inwardly of the aforementioned perpendicular line, so as to provide a maximum passage for the pipe, it would be necessary to either space the swingable jaw a greater angular distance from the fixed jaws, and thereby greatly increase the load thereon, or lengthen the jaws, and thereby necessitate enlargement of the ring and overall tongs.

An object of this invention is to provide power tongs of this type in which the jaws thereof may be arranged so as to grip the pipe in substantially balanced relation without enlarging the overall size of the tongs.

A more particular object is to provide power tongs of the character described in the foregoing object which may be constructed with only a small number of modifications to those shown in the aforementioned patent.

These and other objects are accomplished by means of power tongs which, as in the case of prior tongs of this type, include a frame, a ring rotatably mounted on the frame, and a carrier having a central opening therein and supported for rotation coaxially of the ring. As is also the case in the prior tongs, the ring and carrier have side openings therein alignable in one relative rotative position therebetween to pass a pipe into and out of the central opening of the carrier, and means are provided for rotating the ring with respect to the carrier.

In accordance with the present invention, however, one

pipe gripping jaw is fixed to the carrier opposite the side opening therein and the other two jaws are mounted on the carrier for movement between retracted positions and operative positions for gripping a pipe on opposite sides of the fixed jaws; and parts on the ring are engageable with said jaws during rotation of the ring from side opening aligning position to another position for moving them from retracted to operative positions. Inasmuch as the jaws on both sides of the fixed jaw are movable Tinto retracted position, a full passage may be provided therebetween into the central opening of the ice carrier. At the same time, both of the movable jaws may be arranged for gripping the pipe in the operative positions thereof at points equally angularly spaced apart from one another and the fixed jaw.

In accordance with a further novel aspect of the in,- vention, the jaws are moved from operative to retracted, as well as from retracted to operative, positions in response to rotation of the ring between side opening aligning and said other position. In one form of the invention, the movable jaws are swingably mounted on the carrier, and the parts on the ring engageable therewith for swinging them from retracted to operative positions comprise rollers which, as in the case of prior tongs of this type, preferably rotatably mount the carrier. In another form of the invention, the jaws are swung from retracted to operative positions by cam surfaces on the ring which engage the jaws during rotation of the ring from side opening aligning to said other position. Preferably, the cam surfaces on the ring engage the jaws along rollers carried thereby.

In the first-mentioned form of the invention, one of the swingable jaws is also engaged by a part, such as a roller, on the ring to swing it from operative to inoperative position during rotation of the ring from said other to said side opening aligning position. On the other hand, a spring on the carrier urges the other swingable jaw into retracted position upon such rotation of the ring. In the second-mentioned form of the invention, both of the swingable jaws are so urged by springs on the carrier.

In the drawings, wherein like reference characters are used throughout to designate like parts:

FIG. 1 is a plan view of the first-mentioned form of power tongs constructed in accordance with the invention, with a cover for the bottom portion of the frame removed therefrom and shown face up to the right side thereof;

FIG. 2 is a perspective exploded view of the carrier and jaws of the power tongs of FIG. 1;

FIG. 3 is a sectional plan view of part of the tongs of FIG. 1, with the jaws thereof in retracted position;

FIG. 3A is a cross-sectional view of such tongs, as seen along broken line 3A3A of FIG. 3;

FIG. 4 is a view similar to FIG. 3, but with the jaws thereof in operative position about a pipe;

FIG. 5 is a sectional plan view of part of the secondmentioned form of tongs, with the jaws thereof retracted;

FIG. 5A is a cross-sectional view of the tongs of FIG. 5, as seen along broken line 5A-5A thereof; and

FIG. 6 is a view similar to FIG. 5, but with the jaws thereof in operative position about a pipe.

Turning now to the above-described drawings, the frame of the power tongs shown in FIG. 1 includes a bottom portion 10 and a cover 11 removably securable over the bottom portion by means of suitable securing parts, such as bolts, received through aligned holes 12 in brackets 13 toward the rear end of the frame as Well as holes 14 toward the front thereof. The bottom portion 10 and cover 11 of the frame are provided with coaxially disposed central openings 15 and 16, respectively, for receiving a pipe 17 therethrough. Side openings 1S and 19 in the bottom portion and cover of theframe connect the front thereof with the central openings.

As can be seen from FIG. 1, the bottom portion 10 of the frame is also provided with suitable driving mecha nism 21 adapted to impart rotary movement to a shaft 22 toward the rear end of the frame, for a purpose to be described hereinafter. The rear end of the cover 11 is recessed at 23 to accommodate the portion of the drive mechanism surrounding the shaft 22. The details of the driving mechanism, as well as the above-described frame, are unimportant to the present invention and are menframe.

tioned merely to provide a proper background for the novel apparatus described below.

As in the power tongs of the above-mentioned prior patent, the frame provides a housing for a plurality of

rollers

24 and 25 and a ring 26 is rotatably mounted by the rollers coaxially of the central openings in the frame. For this latter purpose, and'as best shown in FIG. 3A, the periphery of such rollers are grooved at 27 for receiving projections 28 on the outer periphery of the ring 26. As shown in FIG. 1, the shafts of the rollers 25 disposed at opposite sides of the side openings 18 and 19 in the frame are rotatably journaled within openings 29 in the cover 11.

As is also the case in the tongs of the previously mentioned patent, a side opening 30 in the ring connects the exterior thereof with the central opening 31 therein. More particularly, the ring is rotatable within the frame between the position of FIG. 3 for aligning the side opening 30 therein with the side openings in the frame for passing the pipe 17, and another position, in which such side openings are disali-gned, as shown in FIG. 1. For this latter purpose, an endless chain 33 is driven by the mechanism 21 for operative engagement with sprocket teeth 32 about the ring above the projection 28 thereon. Thus, suitable idler pulleys 34 are mounted upon the bottom portion of the frame, as shown in FIG. 1, for guiding the chain 33 in a manner obvious from the drawings and as previously described in the above-mentioned patent.

It is also obvious from the drawings that rotation of the shaft 22 of the driving mechanism in a counterclockwise direction will rotate the ring 26 in a clockwise direction, while rotation of such shaft in a clockwise direction will rotate the ring counterclockwise. Thus, with reference now to FIGS. 3 and 4, the shaft 22 may be rotated in a counterclockwise direction so as to rotate the ring 26 from the position of FIG. 3 in which its side opening 30 is aligned with the side openings in the frame, to the position of FIG. 4, in which such side openings are disaligned. Of course, rotation of the shaft in a reverse direction will move the ring from the position of FIG. 4 to that of FIG. 3. As can be seen from FIG. 1, the upper ends of the shafts of the idler pulleys may be journaled within suitable bearings 35 in the cover 11 of the Obviously, other means may be provided for rotating the ring within the frame.

Again as in the case of the above-mentioned patent, a carrier 36 is rotatably mounted within the central opening 31 of the ring 26 by means of a plurality of spaced apart rollers 37 rotatably mounted within an internal re- .cess 38 of the ring intermediate its central opening and band are provided with loops 43 adapted to receive pins 44 releasably securable within holes 45 in the cover 11 of the frame (see FIG. 1) so as to tightly hold the brake band about the carrier. In this way, the carrier is prevented from rotating with the ring during rotation of the ring between the'positions of FIGS. 3 and 4.

The carrier is also provided with a central opening 46 therein disposed coaxially of the central openings in the ring and frame, and a side opening 47 therein connecting the front portion of the carrier with the central opening.

It will be noted that the diameter of such central opening 46 and the width of side opening 47 are substantially equal to the width of side opening 30 in the ring 26. More particularly, the carrier is supported by the ring 'in a manner to dispose its side opening 47 in alignment with the side opening 30 in the ring 26 in one relative rotative position therebetween for passing the pipe 17 into and out of the central opening in the carrier, as shown in FIG. 3. On the other hand, with the carrier held tightly by the brake band 42, the carrier 36 is rotatable with respect thereto from the position of FIG. 3 to the position of FIG. 4, in which latter position the side openings in the carrier and ring are disaligned.

As best shown in FIG. 2, a replaceable die 48 is mounted on the central opening 46 of the carrier opposite the side opening 47 therein to provide a fixed jaw for gripping the pipe 1 7 as the latter is passed into the central opening of the carrier. The carrier is recessed at 49 and 50 along opposite sides and intermediate flanged portions 39 and 39a to receive

swingable jaws

51 and 52, respectively. The jaw 51 is swingably mounted on the carrier by means of a pin 53 received through an open ing 54 in one end of the jaw and

openings

55 and 56 in the carrier for swinging between a retracted position, as shown in FIG. 3, and an operative position, as shown in FIG. 4, in which it'grips the pipe. The jaw 52 is swingably mounted by means of a pin 57 received through an opening 58 in one end of the jaw and openings 59-and 60 in the carrier for swinging between the retracted position of FIG. 3 and the operative position of FIG. 4. As can be seen from FIG. 3, in their retracted positions,

.the swinging

jaws

51 and 52 provide a full passage into the central opening in the carrier so as to receive a pipe 17 of maximum size. In their operative position, these jaws grip the pipe 17 at points substantially equally spaced from one another and from the fixed jaw 48i.e., at approximately degree intervals. Each

jaw

51 and 52 is provided with replaceable dies 61 on the end thereof opposite the pins 53 and 57 for gripping the pipe 17 in the manner shown.

As can be seen from FIGS. 3 and 4, the outer portions of the

swingable jaws

51 and 52 are, in both positions thereof, closely received within the inner groove 38 of the ring 26 so as to provide support for the front portion of the carrier 36 within the ring. Obviously, however, the top and bottom sides of the jaws are not so tightly held within this groove as to prevent their swinging when urged in the manner to be described; and, in fact, such swinging is facilitated by suitable lubrication between the adjacent surfaces between the jaws and ring groove.

Rollers 62 are rotatably mounted within the groove 38 of the ring on opposite sides of the side opening 30 therein. One of these rollers (the leftmost in FIGS. 3 and 4) is engageable with a cam surface 63 on the outer side of the swingable jaw 51 during clockwise rotation of the ring with respect to the carrier from the position of FIG. 3 to that of FIG. 4 to swing the die 61 of such jaw into gripping engagement with the pipe. On the other hand, one of the rollers 37 (the rightmost in FIGS. 3 and 4) is engageable with a cam surface 64 on the outer surface of the jaw 52 during such rotation of the ring to swing the die of such jaw into gripping engagemcnt with the pipe 17. More particularly, these rollers and cam surfaces are arranged to swing the jaws into gripping engagement with the pipe substantially simultaneously with one another. Upon gripping the pipe, the

jaws

51 and 52 transmit force from the ring to the pipe as well as from the ring to the carrier which is sufficient to overcome the frictional resistance of the brake band 42 so as to rotate the carrier and pipe with the ring upon continued rotation of the latter. Thus, the tongs are useful in making and breaking a threaded connection of the pipe 17 with another pipe section. That is, for example, if the connection is made upon rotation of the pipe in a clockwise direction with the tongs positioned as. shown, such tongs may be turned over to break the connection.

Obviously, rotation of the ring in a counterclockwise direction from the FIG. 4 to the FIG. 3 position moves roller 37 out of forceful engagement with cam surface 64 'tor'elieve the gripping engagement of the jaw with the pipe, whereby the brake band 42 is again operative to prevent relative rotation between the carrier and ring. With the carrier so held, the other roller 62 (rightmost in FIGS. 3 and 4) moves into engagement with cam surface 65 on the front end of the jaw 52 to swing it from operative to retracted position. In this latter position of the jaw 52, the rightmost roller 37 is disposed within a recess 66 on its outer side adjacent cam surface 64.

The jaw 51 is, on the other hand, normally urged toward the retracted position of FIG. 3 by means of a leaf spring 67 or the like secured to an inwardly facing portion of the carrier opposite the groove 40 therein. As best shown in FIG. 3, the free end of the spring 67 engages the rear surface of a toe 68 on the rear end of jaw 51 so as to normally urge the die 61 in a clockwise direction. Thus, as the ring is rotated in a counterclockwise direction with respect to the carrier, from the position of FIG. 4 to that of FIG. 3, the roller 62 is moved out of engagement with the cam surface 63 thereon so that the jaw is free to swing into retracted position under the aforementioned urging of the spring 67. More particularly, the jaw is located in its retracted position by means of a recess 69 on its outer surface engageable with the leftmost roller 37, such that its cam surface 63 is positioned for engagement by the roller 62 upon clockwise rotation of the ring from the position of FIG. 3 to that of FIG. 4. The rightmost roller 62 and pivotal axis of the jaw 52, as well as the inner end of cam surface 65, are so arranged that the latter limits rotation of the ring in a counterclockwise direction with respect to the carrier beyond the position thereof shown in FIG. 3. On the other hand, when there is no pipe within the central opening of the carrier, rotation of the ring with respect to the carrier in a clockwise direction is limited by means of the outer end of cam surface 63 of jaw 51 which, in cooperation with the spring 67 prevents a counterclockwise rotation of the jaw 51 about its pivotal axis.

Obviously, the contouring of the cam surfaces on the jaws and the relative location of the pivotal axis of such jaws and the rollers engageable therevw'th may be varied in order to obtain desired force characteristics. However, such variations are well within the scope of one skilled in the art, and therefore do not require more detailed attention in the present application.

a frame (not shown) as described in connection with the other form. As shown in FIG. 5A, the inside of :the ring 71 is grooved at 74 to receive flange elements 75 which project inwardly of the central opening 76 in the ring to fit within a groove 77 formed about the periphery of the rear end of the carrier 78 for rotatably supporting the same. As is apparent from the drawings, the carrier is, in the above respects, similar to the carrier 36 of the first form of the invention. Thus, for example, as shown in FIG. 5A, a brake band 79 surrounds an upper peripheral portion 80 of the carrier for preventing its rotation with the ring prior to engagement of the

jaws

81 and 82 swingably carried thereby with the pipe 17 disposed within the central opening 76 of the carrier. As was also the case in the previously described form of the invention, the outer portions of the

jaws

81 and 82, which are swingably mounted from the carrier by means of

pins

83 and 84, respectively, are received within the inner groove 74 of the ring to provide support for the front portion of the carrier.

As will also be seen from FIGS. 5, 5A and 6, the carrier is provided with a fixed jaw 85 thereon opposite side opening 86 therein connecting with the central,

opening 76, and the

jaws

81 and 82 are engaged by parts on the ring 71, during rotation of the ring in a clockwise direction with respect to the carrier, to move the jaws from the retracted position of FIG. 5 to the operative positon of FIG. 6, in which latter position dies 87 on the inner surfaces of the jaws grip the pipe at points substantially equally spaced from one another and from the fixed jaw 85. However, in accordance with this second form of the invention, these parts on the ring for engaging the

jaws

81 and 82, respectively, comprise cam surfaces 88 and 89 formed on the inner surfaces of the groove 74. In a preferred embodiment of this form of the invention, these cam surfaces are engageable with

rollers

90 and 91 rotatably mounted on the outer surfaces of the jaws for facilitating moving of the cam surfaces thereover. Obviously, continued rotation of the ring in a clockwise direction will turn the pipe 17 in the same direction. Also, of course, the tongs may be turned over for use in rotating the pipe in an opposite direction.

The

jaws

81 and 82 are normally urged toward retracted position by means of

springs

92 and 93, respectively, secured to the inner surface of the carrier opposite the groove 77 therein and engaging at their outer ends with

toes

94 and 95 on the rear ends of the jaws. Thus, when the ring is rotated in a counterclockwise direction with respect to the carrier so that the cam surfaces 88 and 89 are moved out of forceful engagement with the

rollers

81 and 82, such rollers are urged by the

springs

92 and 93 into the retracted position of FIG. 5. I

When there is no pipe within the central opening of the carrier, the swinging of jaw 81 in a counterclockwise direction is limited by the curved inner'end of the cam surface 88. That is, as will be understood from FIG. 6, when the jaw 81 reaches approximately the position shown, this end of the cam surface will cooperate with spring 92 in preventing further clockwise rotation of the ring. On the other hand, rotation of the ring with respect to the carrier in a counterclockwise direction beyond the position shown in FIG. 5 is limited by the cooperation between the spring 93 and a cam surface 97 on the groove 74 of the ring with which the roller 91 of the jaw 82 is engageable.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent in the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention Without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. Power tongs, comprising a frame, a ring rotatably mounted on the frame, a carrier having a central opening therein and supported for rotation coaxially of the ring, the ring and carrier having side openings therein alignable in one relative rotative position therebetween to pass a pipe into and out of the central opening of the carrier, means for rotating the ring with respect to the carrier, a jaw fixed to the carrier opposite the side opening therein, a pair of jaws mounted on the carrier for movement between a retracted position for passing a pipe and an operative position for gripping a pipe on op posite sides of the fixed jaw, means responsive to rotation of the ring with respect to the carrier in one direction from side opening aligning to another position, re-

spectively, to move the jaws from retracted to operative giositions', and responsive to rotation of said ring with respect to the carrier in the opposite direction from said other to side Opening aligning position to move the jaws from operative to retracted position and hold them in said retracted position and rotate the carrier with the ring upon further rotation of said ring in said opposite direction.

2. Power tongs, comprising a frame, a ring rotatably mounted on the frame, a carrier having a central opening therein and supported for rotation coaxially of the ring, the ring and carrier having side openings therein alignable in one relative rotative position therebetween to pass a pipe into and out of the central opening of the carrier, means for rotating the ring with respect to the carrier, a jaw fixed to the carrier opposite the side opening therein, a pair of jaws mounted on the carrier for swinging between a retracted position for passing a pipe and an operative position for gripping a pipe on opposite sides of the fixed jaw, parts on the ring engageable with said jaws, during rotation of the ring with respect to the carrier in one direction from side opening aligning position to another position, for moving them from retracted to operative position and engageable with one jaw, during rotation of the ring with respect to said carrier in the opposite direction from said other position to said side opening aligning position, for moving said one jaw from operative to retracted position, and a spring on the carrier urging said other jaw into retracted position upon rotation of the ring into said side opening aligning position, said jaws being held in retracted position and said carrier being rotatable with the ring upon further rotation of said ring in said opposite direction.

' 3. Power tongs, comprising a frame, a ring rotatably mounted on the frame, a carrier having a central opening therein and supported for rotation co-axially of the ring, the ring and carrier having side openings therein alignable in one relative rotative position therebetween to pass a pipe into and out of the central opening of the carrier, means for rotating the ring with respect to the carrier, a jaw fixed to the carrier opposite the 'side opening therein, a pair of jaws mounted on the carrier for swinging between a retracted position for passing a pipe and an operative position for gripping a pipe on opposite sides of the fixed jaw, parts on the ring engageable with said jaws, during rotation of the ring with respect to the carrier in one direction from side opening aligning position to another position, for moving them from retracted to operative position, and springs on the carrier urging said jaws into retracted position upon rotation of the ring with respect to said carrier in the opposite direction from said other position into side opening aligning position, said jaws being held in retracted position and said carrier being rotatable with the ring upon further rotation of said ring in said opposite direction.

References Cited in the tile of this patent UNITED STATES PATENTS 1,218,488 Stromberg Mar. 6, 1917 2,618,468 Lundeen Nov. 18, 1952 2,650,070 Lundeen Aug. 25, 1953 2,703,221 Gardner Mar. 1, 1955 2,737,839 Paget Mar. 13, 1956 2,741,460 Gardner Apr. 10, 1956 2,760,392 Paget Aug. 28, 1956 2,780,950 Province Feb. 1 2', 1957 2,846,909 Mason Aug. 12, 1958 2,879,680 Beeman et a1. Mar. 31, 1959