US2950639A

US2950639A - Power operated pipe wrench

Info

Publication number: US2950639A
Application number: US754237A
Authority: US
Inventors: James C Mason
Original assignee: MASON CARLTON TOOL CO
Current assignee: MASON CARLTON TOOL CO
Priority date: 1958-08-11
Filing date: 1958-08-11
Publication date: 1960-08-30
Anticipated expiration: 1977-08-30

Description

ug. 30, 1960 J. c. MASON POWER OPERATED PIPE WRENCH 3 Sheets-Sheet l Filed Aug. 11, 1958 NS S nl.. il

Aug. 30, 1960 J. c. MASON POWER OPERATED PIPE WRENCH 3 Sheets-Sheer. 2

Filed Aug. ll, 1958 Maz 6.

INVENTOR.

BY faul-Mlm C, g-WIL- Aug- 30, 1960 J. c. MASON 2,950,639

POWER OPERATED PIPE WRENCH Filed Aug. 11, 1958 Y 5 Sheets-Sheet 3 @MES @I Manso/Vy IN V EN TOR.

PWER PERATED PIPE WRENCH James C. Mason, Long Beach, Calif., assigner to M ason- Carlton Tool Co., Paramount, Calif., a corporation rned Aug. 11, 195s, ser. No. 754,237

10 claims. (c1. rs1-53) The present invention relates generally to' oil field equipment, and more particularly to an improved powerdriven pipe tong. This application is contlnuation-inpart of co-pending application tiled June 24, 1954, under Serial No. 439,061 for `a Power-Driven Power Operated Pipe Wrench, which issued August 12, 1958, under Patent No. 2,846,909.

Power-driven pipe tongs are widely employed in oil well drilling and the production of oil. These tongs `are particularly adapted for use in rapidly screwing and unscrewing the threaded ends of strings of casing, drill pipe .and tubing utilized in the bore hold of an oil well, in that they permit considerable saving of time and money.

Additionally, these power tongs are far safer in actual use than conventional pipe tongs previously available, for they are power-operated and substantially eliminate the manual labor and physical hazards heretofore encountered in running a string of casing, drill pipe, or tubing into a well bore or in removing the same therefrom.

A major object of the present invention is to provide an improved power tong by means of which a more eiicient and versatile transmission of power from the prime mover to the pipe-engaging elements thereof is elected, which rotatably and adjustably supports the pipe-engaging elements in a manner to compensate for wear thereof as well as to minimize transmission of sudden shock thereto when the dies assume a pipe-engaging position, and `allows for selective variation in the latching -force to that required for a particular job.

Another object of the present invention is to provide an improved power tong that is more compact, lighter in weight, simpler in construction, and more versatile in operation than the tong disclosed in my previously mentioned Patent No. 2,846,909.

These and other objects and advantages of the present invention over the device disclosed in my previously mentioned Patent No. 2,846,909, will become apparent from the Ifollowing description of a preferred embodiment thereof, and from the accompanying drawings, wherein:

Figure l is a side elevational view of the improved power tong of the present invention;

Figure 2 is a top plan view of the tong shown in Figure l, taken on line 2 2 thereof;

Figure 3 is a fragmentary vertical cross-sectional view of the transmission gear train and reversible iiuid motor forming .a part of the invention, .taken on line 3-3 of Figure 2;

Figure 4 is a fragmentary vertical cross-sectional view of one of the pairs of rollers which rotatably support the half rings on which the die carriers are mounted, taken on line 4 4 of Figure 2;

Figure 5 is a top plan view of one of the adjustable roller support indexing plates, taken on line 5-5 of Figure 4;

Figure 6 is a fragmentary, vertical cross-sectional view hired rates Patent i 2,950,639 Patented Aug. 30, 1960 ICC of a portion of the transmission land, manually operated gear shift taken on line 6-6 of Figure 2;

Figure 7 is a fragmentary top plan view of a frame member and jaw member `adapted to be held in rigid ,abutment -by the power-actuated latch .as shown, with portions of the frame and jaw being broken away to disclose portions of the half rings, die carrier and dies, and the manner in which they are supported on the frame and jaw by the rollers shown in Figures 4 .and 5;

IFigure 8 is a fragmentary elevational View of the latch in a position to maintain the frame and jaw in the closed position of Figure 7;

Figure 9 is a fragmentary horizontal cross-sectional view of the power-operated cam and cam-engageable member shown in Figure 7; and

Figure l0 is an exploded perspective view of a half ring, die carrier and die block.

With `further reference to the `drawings for the general arrangement of the invention, and particularly Figures l and 2 thereof, it will be seen to include a frame member F which pivotally supports a jaw I that is adapted to be secured in a closed position relative thereto by means of `a power-operated latch L. Frame member F and jaw l are so constructed as to define a circular pipereceiving opening O in which a tubular member P can be inserted or from which it may be removed when jaw l is in an open position relative to frame member F.

It will be understood that member P may comprise either casing, drill pipe, or tubing normally inserted in the bore hole of an oil well. Frame member F and jaw l, as can best be seen in Figures 3, 4, and 6, are of hollow construction. Two identical semi-circular half rings B are provided, one of which is shown in Figure l0. These half rings are rotatably supported within the confines of frame member F and jaw I, respectively, to encircle opening O (Figures 3 and 7).

Two identical semi-circular die carriers C are also provided, one of which is shown in Figure l0 and partially in Figure 3. Carriers C support a number of circumferentially spaced die blocks D, and in turn carriers C are supported by half rings B. The outermost end surfaces of blocks D relative to tubular member P are of curved convex configuration, vand these curved ends slidably engage cam surfaces formed, or otherwise provided, on half rings B.

When half rings B are rotated relative to carriers C, the die lblocks D are moved radially inward to engage the exterior surface of tubular member P and rotate the same. A uid actuated motor H is mounted on the upper surface of frame member F (Figure l) and is connected by means of a conduit U to a source of uid under pressure (not shown). A first manually operable valve K directs fluid under pressure from conduit U to motor H and selectively actuates the same in either of .two possible directions for reasons to be hereinafter explained. A second valve G selectively directs uid from conduit U to a hydraulic cylinder V, as best seen in 'Figure 2, which cylinder actuates latch L to maintain frame F and jaw I in the closed position or release them therefrom.

Motor H drives a `gear train T (Figures 2 and 3) to rotate half rings B. By means of the manually operable `gear shift N shown in Figure 6, `gear train T can be caused to rotate half rings B at either high speed, low torque, or high or low speed, high torque. A support Q for the invention above described is shown in Figure 1, which maintains frame member tF and jaw J in a desired horizontal position relative to the tubular member P being rotated. A handle R 4is mounted on jaw I (Figures l and 2), by means of which the jaw may be pivoted outwardly away from the forward extremity of frame member F when latch L is manually pivoted out of en- Ycenters `of pockets 58.

F andfjaw J whereby Vthey may be moved toward or away from half rings B, for reasons to be explained heretinafter.' Frame member F (Figures l, 2 and 3) includes a bottom'wall 28, a side wall 30, and a top wall orV cover 32, the edges of which walls' are integrally joined. Y Rollers X, as may be seen in Figure 4, are preferably of the ball or roller bearing type and mounted in pairs on shafts 33. Theend Vportions of each shaft are disposed in longitudinally extending, olf-centered bores 34 formedin bosses 35 that are normally disposed and Vvrigidly affixed relative toindexing plates 36. The

end portions ,of shafts 33 are aliixed .to at least one of the bosses 35 in which they are disposed by means of a pin 33a, or other fastening means. Should it be desired, commercially available stock bolts can be used in place of shafts 33 as shown in Figure 4.Y Pairs of vertically aligned openings 37 are formed in frame F and jaw I which are circumferentially spaced around opening O, aud-one of the bosses 35 is rotatably disposed in each opening 37. Y

A plurality of circumferentially spaced bores 35 are formed inleach indexing plate 36 through which bores screws 39 extend to engage a number of tapped bores formed in frame F and jaw J around openings 37. Rotation of indexing plates 36 moves shaft 33 and rollers X toward or away from half rings B whereby the pressure contact between the' rollers and half rings can be controlled. Movement of rollers X'toward half rings B by rotation of indexing plates 36 is also highly desirable in order to compensate forwear on the half rings after prolonged use. Engagement of screws 39 with aligned bores 38 and tapped bores 40 rigidly maintains shafts 33 and rollers X at the desired'position relative to half rings B. One-half of a ring gear 41 is aiixed'to the central exterior surface of each half ring B (Figure l0), vand this gear maintains rollers X in the spaced relationship shown in Figure 3. Y

The rear portion of jaw J is pivotally secured to frame member F by a vertical pivot pin 42. structurally, Yjaw I is generallyV similar to the'front portion of frame F, and has simiiar bottom, side and top walls. Rollers X may be adjustably supported in jaw J by the same type of mounting assemblies employed with jaw I, as shown inV detail in Figure 4. f Y

Each half Yring B includes a vertical wall 48 from which lowerY` and upper lianges 50 and 52 respectively,

project radially inward. Ring gearr41 can Ybe either Y rigidly amxed to, or formed as an integralY part of half ring B. The exterior surfaces of walls yi8V are `in rolling contact with rollers X, as may be seen in Figure 7. A

i number of circumferentially spaced Wedging members 56 Y are formed on the interior` surfacesY of

walls

48,7 and each wall defines a Wedge-shaped pocket 58 which receives an end portion of one of the die blocks D. Arcuate grooves 60 .are Vformed in the upper anges 52 that slidably receive and rotatably engage track A (Figure 3). Upper Y pipe-engaging dies Y, preferably formed with a serrated or otherwise roughened exterior pipe-engaging face. Dies Y are fabricated froma hard, tough` material that is resistant to abrasion and are of such transverse cross section as to be slidably insertable or removable in slots S3. Dies Y are rigidly maintained within the connues of slots 82 by means of screws, or other Vconventional means (not shown). Y.

Referring to Figures 3 and 7, it will be seen that engagement of ring gear 41 witha toothed driving roller S8 causes half rings B to Yrotate relative to frame element F and jaw I when they are in the closed position. Driving roller 88 is rigidly mounted on a rst shaft 90 that is rotatably supported by two vertically spaced bearings 91and 92. Bearing 91'is mounted on wall 23 of frame F and bearing 92 on a bracket 93 aflxed to wall 28 that projects upwardly therefrom land is situated within the confines of the-frame.V

A driven rollerr88a is also rigidly affixed to rst shaft 90 and at all times engages a rst pinion 94 which is rigidly mounted on a second vertical shaft 9S, the end portions of which are rotatably mounted in a pairof Ybearings 95a supported by frame F. A second pinion p 96, considerably larger in diameter than pinion 94, is

also rigidly aixed to shaft' 95, above pinion 94.

A third shaft 97 that is lparallel to second shaft 95 is rotatably supported by a pair of bearings 97a from frame F. The gear shift mechanism N, -as best seen in Figure 6, permits selective rotation 'of die blocks D Vat low speed, high torque, or highv speed, low torque. Splines 98 are formed on shaft 97 that slidably engage keyways 99 provided in an upper-gear 100 and a lower gear 102.

Gears

100 and 102 are slidably supported on shaft 97, but rotate'concurrently therewith. Gear 100 is considerably smaller in diameter than Ygear 102, and an intermediate- Vly disposed tubular member 104 having ya circumferential-Y ly extending lgroove 105 :formed therein rigidlyconnects and lower'anges 52gand 50 also have Ia-number of pairs Y Vof vertically aligned slots y62 and 63 respectively, formed therein, the centersrof which are in alignment with the Y Die carriers C are positioned between the lower and upper ilanges 50 and 52, as Vshown in Figures 2, 3 and 7 Eaclrcarrier C is formed with a number of generally reotangulanradially extending openings 64 adapted to be Y aligned-,With the wedging member Vpockets 58. Verticallyalignedrbores 66 and 6,8.are formed in each die carrier ,f C that communicate with openings 64. Lightening holes Vmay also be formed in each half ring B, as shown rin Figure 10; Y

these gears. 4 Y

A rigid ring-shaped Vmember 106 is slidably supported ingroove 105, and two pins 107 Vproject outwardly from opposite sides thereof. A YbifurcatedV member 108 engages pins 107 that is in turn pivotally connected to one 'rend of a Vgenerally horizontal level-109 which terminates in an upwardly Yextending handle 1710 that projects through an opening 111 formed'jin frame cover 32.V Lever 109 is pivotally mounted on a horizontal shaft 112 affixed to 'theupper end portions of two Vlaterally separated arms 1013 which projectupwardly intdframe F from wall 28 thereof. Y Y Y Y Y vA fourth verticalshaft 114 is Irotatably supported by a pair ofbearings'llia mounted onwalls 32 and 2S, as shown in Figure 3. A'lower toothed member Y115 and *upper toothed memberA llsomewhat'larger inV diameter are rigidly aXed-to shaft114. Member 116 is at all times in4V engagement with a driving gear 117 mounted on a verticalV drive shaft 118 that extends upwardly to Yiluil actuated motor TheT lower end of shaft 118 is journalled in a bearing V11,9 that isrsupportedon wall 2S.'

Manual manipulation of handle Y110 moves lever 109V and bifurcated member 108 to place gears 100 and V102 intherst Vpositionrshown in Figure 3 where Vgea-r 102 ,engages first' pinion 94 and' -toothed member 11S. Gears 'and 102 can also be moved by use of gear shift N to a second position in which 'gear' 100 engages second pinion' 96; while gear 102 'remains in' Vengagemerrt with toothed. member 115, but out of engagement with first pinion 94. Gear shift N also permits

gears

100 and 102 to be moved to a third, or neutral position, wherein gear 100 does not engage any toothed member, and gear 102 is in engagement with toothed member 115 but out of engagement with first pinion 94. Thus, by manipulation of handle 110, the gear shift mechanism N causes motor H to rotate half rings B, die carriers C, and die blocks D at either high speed, low torque, or low speed, high torque.

The support Q (Figure 1) includes a rigid bar 130 that is bent, or otherwise formed, to `denne a first downwardly extending leg 132 that is pivotally connectedv on the lower end portion thereof by a pin 134 to a lug 136 which projects upwardly from frame F. Bar 130 also delines a second upwardly extending leg 138 that is angularly positioned relative to leg 132. The upper extremity of leg 138 terminates in an eye 146, which by means of a cable 142 aixed thereto, supports the tong from a convenient portion of the derrick structure (not shown). A manually adjustable turnbuckle 144 is pivotally connected to the upper portion of leg 138, and to a suitable fastener 146 affixed to top wall 32 a considerable distance inwardly from lug 136. By manipulation of turnbuckle 144, frame F and jaw I may be pivoted relative to support Q to place the tong in a true horizontal plane. The rear end of frame F terminates in a heavy, horizontally positioned lug 147 in which a vertical bore is formed that receives a pin 148 and pivotally supports an eye-defining member G. A dead line 152 is connected to member 150 and a portion of the derrick (not shown) to restrain rotation of the tong during a pipe screwing operation.

. Conduit U conducts uid from a source under pressure (not shown) to tirst valve K, and upon manipulation of a handle 158 provided on the valve, uid can be discharged into the motor to cause selective rotation thereof in either of two possible directions. After actuation or motor H, fluid is directed back to its source through a second conduit Z for recirculation through conduit U.

In detail, conduit U (Figures l and 2) includes a T connection 161) from which a tubular lateral 162 extends to the inlet side of motor H, and an extension 164 of conduit U continues from T 160 to the inlet side of second valve G.

Valve G, by means of a control handle 165 associated therewith, is capable of discharging fluid through either of two

conduits

166 or 168 extending to opposite ends of the hydraulic cylinder V. When handle 165 is placed in a first position, fluid is'discharged through conduit 166 to enter cylinder V and move a piston 172 disposed therein to the left, as shown in Figure. 2. Fluid on the side of piston 172 opposite that contacted by the incoming iiuid is discharged through conduit 168 to return to second valve G. Fluid so returning to second Valve G is discharged therefrom through a conduit 174, which by conventional means, is connected to conduit Z and returned to its source for recirculation. When handle 165 is placed in a second position, liuid entering the valve from conduit U is discharged from the valve to conduit extension 168 to enter cylinder 170 and force piston 172 to the right (Figure 2) with the uid on the side of the pistons communicating with conduit 166 being discharged therethrough to return to valve G and thereafter discharged through conduit 174 to conduit Z.

, Piston 172 has a piston rod 176 aixed thereto, which extends forwardly to a position above the latch mechanism L. The end of cylinder V opposite that from which Vpiston rod 176 projects is pivotally connected by a pin 177 to jaw l. Latch mechanism L includes two horizontal,'vertically spaced supporting plates 178 and 178 'which are -welded or otherwise affixed to the forwardly disposed, vertically extending side walls of jaw I, as best seen in Figures 2, 7 and 8. A heavy vertical shaft 180 6 is journaled in vertically aligned, longitudinally extending slots 181, 181' formed in plates 178, 178' respectively, and an outwardly projecting arm 182 is rigidly atiixed to shaft 180. The outer extremity of arm 182 is pivotally connected by a pin 184 to the outer extremity of the piston rod 174.

An intermediately positioned cam or eccentric 186 is rigidly affixed to shaft 188 by conventional fastening means. When shaft is rotated in a counter clockwise direction (Figures 7 and 9), cam 186 is brought into rotatable sliding contact with a heavy rigid camengageable member 188 that projects outwardly from jaw I. This rotatable contact between cam 186 and member 188 forces shaft 180 to the right in slots 181, 181'.

Latch mechanism L lalso includes an engaging member 196 and an engageable member 191. Member 190 comprises two parallel, laterally spaced

legs

194, 194 that are connected by a web 196 extending between the end portions thereof, as best seen in Figure 8. Two aligned bores 198, 198' are formed in the end portions of

legs

194, 194 opposite those joined by web 196, and these bores rotatably engage shaft 180. With engaging member 196 supported as described above, an end portion of leg 194 is disposed between the lower face of plate 17S land upper face of cam 186, and an end portion of leg 194 is located between the lower face of cam 186 and the upper face of plate 178".

Engageable member 188 preferably includes a vertical plate 208, the inner edge of which is welded or otherwise affixed to the forward portion of jaw side Wall 30. To strengthen plate 200 against stress and strain, it is preferably reinforced by two parallel vertically spaced ribs 202 that are rigidly affixed to wall 30. Two set screws 204 are threaded into tapped bores formed vin web 196, and the end portions thereof are capable of being adjusted to a desired distance inwardly from web 196. A handle W is mounted on the latch engaging member 190 that permits pivotal movement of the engaging member to a position where it may be placed in engagement with engageable member 191 (Figure 7), or to a position where it is out of engagement therewith, whereby jaw l may be swung away from frame F, which is necessary when pipe P is placed in or removed from opening O. The further the set screws 204 project to the right from web 196 Ias` seen in Figure 7, the less movement the piston rod 176 will be required to make to bring the ends of the set screws 204'into pressure contact with a at face 191e of engageable member 191.

The use of the invention is extremely simple. When it is desired to place a tubular member P within the confines of opening O, the latch L is disengaged and handle R is employed to swing j aw I outwardly away from frame member F. The tubular member to be screwed or unscrefwed from a corresponding section thereof is placed inside frame member IF and jaw I and the jaw then swung toward member F by means of handle R until Vlatch L can be placed in an engaging position. Initial engagement of latch L brings the free ends of jaw I and frame member F into juxtaposition, Ibut not in abutment. Likewise, when latch L is in an engaging position, the half rings B are supported by rollers X, as can best be seen in Figure 4, but without these rollers exerting any substantial radial force on the outer surface of wall 48 thereof. After initial pressure contact of set screws 204 with face 191er is effected as show-n in Figure 7, the handle 165 of second valve G is manipulated to cause fluid ow to the hydraulic cylinder V, with resultant movement of piston 172, piston rod 176, arm 182 and rotation of cam 186 to slidably contact cam plate 200, whereby jaw J and frame member F `are drawn together and the ends thereof are placed in pressure abutment. As jaw I and frame member F are so drawn together, due to previous adjustment of the indexing plates 36, rollers X are so radially disposed relative to half rings B that the rollers X preso 7` o sure contact theexteor surface of the half ring walls 48, as can .best `be seen in Figure j4. The magnitude of the force exerted b y rollers AXeinthis manner is dependent uponY the -positioning of the roller-supporting shafts 33, as well as the magnitude of the fluid `pressure being supplied to the apparatus through conduit U. Y First valve K is then manually manipulated to cause rotation 'of driving' gear 117 and resultant rotation of half rings B, die carries C, and dies D. Y Prior-to rotation, diesY DY moveY radially inward as'previouslyV explained, to engage tubular member P and thereafter cause rotation thereof. Y Y Y I The magnitude of the' torque provided by rotation of dies D can -be controlled by the gear shift N shown in i Figure 6.; When handle :110 of the gear shift is manipulatedr'to place gear 102 in meshing engagement with 'rst pinion 94'iandlower toothed member 1157 the dies D are rotated at "high speed and low torque. However, by movement of handle 110, gears 100 and 162 can be raised to a second position where gear 169 meshes'with second pinion 96 and` gear 102 remains in meshed engagement with the lower toothed member, but is out of engagement with first pinion 94. 'Handle 110 can also'be used in Vvertically placing gears 100 and 102 in a third and neutralpositign in which gear 109 is entirely disengaged and gear 102 is only in engagement Ywithlower toothed member 1i15.' Y Y Y The present invention, .as can 4be seen from the foregoing descn'ption thereof, operates in much the same manner aslmy invention disclosed Iand claimed in my United, States Letters Patent No. 2,846,909, entitled Power Driven Pipe Tong, that issued August 12, 1958. However, the locking mechanism of the previous device for interlocking the half rings together has beenY dispensed with Vwhereby the annoyance andY inconvenience of having'to periodically replace the locking mechanism by use 'ofthe power-operated latch is avoided. In the present invention-the power-operated latch has an initial makeup in vwhich the frame and jaw are not completely closed, but are Velo-sed by actuation of hydraulicvcylinder Vio power move'therjaw and frame into a completely Yclosed position with concurrent application of pressure to the'exterior surfaces of the half rings B to maintain them in a closed, y'circle-defining position during screwing or unscrewingof a tubular member. The transmission T and lgear shift N provided in lthe present4 invention act positively to permit easy change of the gear ratios between ring gear 41 and driving fgear 117 withoutV recourse to the Vclutch mechanism disclosed in my previously mentioned Patent No. 2,846,909. Y Y y 'c .It ,will be obvious to those skilled in the art that various changes may bepmade in the invention without departing fromthe spirit and scope thereof, and therefore Vthe invention/is not limited by that which is shown in Ythe drawingganddescribed in the specification, but Vonly/as indicated in the appended claims.

lclaim: 1- a ,Y 1. A power-driven pipe tongL comprising: a frame member; Ia jaw member pivotallyrsecured to said frame member that cooperates therewith to define a pipe-receiv- YingV opening; track means formed` on said ,members and encompassing said opening; a.pair of support half rings rotatably mounted on said track means; two semi-circular diecarriers rotatably mountedV on said half rings; a plurality of circumferentially spaced, radially movable die blocks mounted onV said die carriers; cam means'v disposed at fixedpositionsV relative to said half `rings,yvhih cam meansA is slidably'engaged'by the exterior ends of said die blocks when said die carriers are rotated in either of two possible directions relative torsaid halfV ringsfwithY Vsaid die' blocks beingrnoved inwardlyfwhensaid slidablemove- `ment `takes placejiuid V,actuated Ypower means;V `'variable speed Vtransmission Ymeans thatconnect saidY power means suddenly rotate said half rings so yas lto cause initial relai tive movement between said'lralf rings and said die car'. riers, due tothe inertia ofthe latter, to the extent that before rotating with said die carriers and half rings said blocks areiirst moved inwardly to grip the exterior'surface ofV a pipe disposed in said opening; fluid operated llatch meansfor releasably locking said frame' and' jaw members together; rst valve means; second Vvalve means; first conduit means connectable to a source of 'tiuid under pressure and extending to said rst and second-valve means land thence to said power means and latch means, said first Valve means being adapted to selectively deliver said iiuid to said powernmeans in either of two possible directions, to pennit rotation of said half ringsn'rdieV car-Y riers` and dies in either of two possiblep directions, said second valve 'means being adapted to selectively deliver said uid to said latching means to Vcauserthe same to assume either a latched or unlatched position, with the magnitude of the 'latching force holding 'said aw' and' frame members togethenbeing directly proportional to the intensity of the iluid pressure supplied thrQUgh .Said conduit to actuate said power means; and second conduit means capable of returningV fluid to said so'urcelduring actuation of said latching means. n v 2. A power-driven pipetong `as Vderned in claim l wherein said latching means includes an 'engageable member rigidly axedto said frame member and an engaging member movably mounted on said jaw member, which engageable andY engaging members are capable of being placed in an 'engaging position when the free ends of said 'iframe and jaw members are adjacent but not inrabutting contact, a cylinder supported Yfrom-said jaw member, va piston slidably mounted inlsaid cylinder, 'a pistonrod lrigidly connected to said piston, movement-imparting means that transmits motion of said piston `rod to said engaging member to force said engaging andY engageable members to drawV said frame and jaw Vmembers together and place said Vfree ends thereof in pressure abutment or permit said engaging and engageable members to assume relative positions where said free ends are out of abutment and said engaging member can be disengaged' fromsaid engageable member, and two tubular connectorsV on the ends of said cylinder and communicatingY with the interior thereof connected to said rst conduit means, with said second valve means being capableV of selectively delivering said fluid to either of said connectors to move said piston in a desired direction and lactuate said movement-impart.- ingrmea'nsl Y 3.'A power-driven pipe tongas defined in claim 2 'wherein a plurality of rollersare provided that rotatably 'tactwith said half 'rings ,when the Vfree ends of said frame and'Y jaw members are in pressure abutment; ,A I Y 4. A` power-driven pipe tong as Vdeined in cl` V3 wherein said transmission means comprise' twohalf ring 'gears aixed to the exterior surfacesof said half rings, a n dn'vengear in engagement with saidV 'half ring gears, a

driving Vgear rotated by said power means, two'mo'vable gears diierent Vin diameter, a gear shift for moving'said 'to saidv half rings to rotate "the'rsame,V said transmission Y Y Y means being'capable of permittings'aid power means'to Vtwo gears, and aY plurality of gears capable of transmitting rotational motion from said driving gear' to said'driven gear through either of said movable two' gears, with said 'shift'when moved to dispose Ia tirst of said two gears in a 'rst position causing said half ring gears/to be driven Vat high speed, lowY torque, and said shift when moved to dis-V prose an second 'of saidV two gears a secondY position causing said half ring gears tofbe driven at low speed,"'high torque.' Y u i..A` power-drivenY pipeV tong las denedrin claim '-1Y wherein` said latch-means includes an engageablemember rigidly axed to said frame member and an engaging member movably mounted on said jaw member, a cylinder supported from said jaw member, a piston 'slidably mounted in said cylinder, :a piston rod rigidly connected to said piston, movement-imparting means that transmits motion of said piston rod to said engaging member to move the same into engagement with said engageable member and out of engagement therewith, and two tubular connectors on the ends of said cylinder, with said second valve means being capable of selectively delivering said fluid to either of said Connectors to move said piston and piston rod in a desired direction to engage or disengage said engaging member from said engageable member.

6. A power-driven pipe tong as dened in claim wherein ra shaft is provided; two parallel vertically spaced plates are rigidly aixed to said jaw member, with said plates having vertically aligned slots formed therein in which the end portions of said shaft are rotatably and slidably mounted; a cam rigidly aixed to said shaft; a cam plate rigidly axed to said jaw member that is rotatably engageable by said cam, with said plate when so engaged by rotation of said cam in one direction causing movement of said shaft away from said engageable member; an arm rigidly ailixed to said shaft and pivotally connected to said piston rod; and said engaging member comprising two parallel legs, the rst ends of which pivotally engage said shaft, a web that extends between the second ends of said legs and is rigidly connected thereto, with said web being adapted to be moved into engagement with said engageable member by rotation of said shaft in said one direction.

7. A power-driven pipe tong as dened in claim 6 wherein at least one set screw is provided that is threadedly mounted in a tapped bore extending through said web and normally disposed relative thereto, said screw having an end portion that projects into the space between said legs and engages said engageable member, which screw upon manual adjustment thereof in said bore varies the length of said end portion to control the distance of travel of said piston in said cylinder before said engaging member is placed in or moved out of engagement with said engageable member.

8. A power-driven pipe tong as dened 4in claim 7 wherein a pivot support is provided that pivotally supports said cylinder from said jaw member, and a handle is afxed to said web to permit placement of said engaging member in a rst position from Where it can be subsequently moved to engage said engageable member prior to said frame and jaw members assuming a closed position, and in any one of a number of second positions where said engaging member is out of engagement with said engageable member, and said jaw and frame members can be pivoted to an openposition.

9. A power-driven pipe tong, comprising: a hollow horizontally disposed frame member; a hollow horizontally disposed jaw member pivotally secured to said frame member that cooperates therewith to dene a pipe-receiving opening, said frame and jaw members having a plurality of pairs of aligned circular openings formed in the upper and lower portions thereof that are circumferentially spaced about said pipe-receiving opening; a plurality of shafts; a plurality of rollers rotatably mounted on said shafts; a plurality of circular supports for said shaft, which supports are rotatably mounted in said circular openings and eccentrically supports said shafts relatively to the longitudinal axis of said pairs of aligned circular openings; indexing means that maintain each of said shaft supports at any one of a plurality of positions relative to the longitudinal axis of one of said pairs of circular openings; a pair of support half rings rotatably mounted in said frame and jaw members and encompassing said pipe-receiving opening, said half rings being `rotatably supported by said rollers, which upon adjustment of said indexing means are capable of pressure contacting said half rings with a desired compressive iforce when said frame and jaw members are closed; two semi-circular die carriers rotatably mounted on said half rings; a plurality of circumferentially spaced, radially movable die blocks mounted on said die carriers; cam means disposed at fixed positions relative to said half rings, which cam means are slidably engaged by the exterior ends of said die blocks when said die carriers are rotated in either of two possible directions relative to said half rings, with said die blocks being moved inwardly when said slidable movement takes place; fluid operated latch means that force said frame and jaw members into a closed position and so maintain the same untii the actuating pressure on said fluid is released; power means; and variable speed transmission means connecting said power means to said half rings to rotate the same, said transmission means being capable of permitting said power means to suddenly rotate said half rings so as to cause initial relative movement between said half rings and said die carriers, ldue to the inertia of the latter, to the extent that before rotating with said die carriers and half rings said blocks `are first moved inwardly to grip the exterior surface of a pipe disposed in said opening.

10. A power-driven pipe tong, comprising: a hollow horizontally disposed Iframe member; a hollow horizontally disposed jaw member pivotally secured to said frame member that cooperates therewith to define a pipe-receiving opening, said frame and jaw members having a plurality of pairs of aligned circular openings formed in the upper and lower portions thereof circumferentially spaced about said pipe-receiving opening; `a plurality of shafts; a plurality of rollers rotatably mounted on said shafts, which supports are rotatably mounted in said circular openings and eccentrically support said shafts relative to the longitudinal axis of said pairs of aligned openings; indexing means that maintain each of said shaft supports at any one of a plurality of positions relative to the longitudinal axis of one of said pairs of circular openings; a pair of support half rings rotatably mounted in said frame and jaw members and encompassing said pipe-receiving opening, said half rings being rotatably supported by said rollers, which upon adjustment of said indexing means are capable of contacting said half rings with a desired compressive force when said frame and jaw members are closed; two semicircular die carriers rotatably mounted on said half rings; a plurality of circumferentially spaced, radially movable die blocks mounted on said die carriers; cam means disposed at fixed positions relative to said half rings, which cam means is slidably engaged by the eX- terior ends of said die blocks when said die carriers are rotated in either of two possible directions relative to said half rings, with said die blocks being moved inwardly when said slidable movement takes place; fluid actuated latch means for releasably locking said frame and jaw members together; fluid actuated power means for rotating said half rings; and uid conducting means capable of supplying uid under substantially the same pressure to both said latch means and said power means.

References Cited in the le of this patent UNITED STATES PATENTS 2,618,468 Lundeen Nov. 18, 1952 2,650,070 Lundeen Aug. 25, 1953 2,703,221 Gardner Mar. 1, 1955 2,741,460 Gardner Apr. 10, 1956 2,780,950 Province Feb. 12, 1957 2,846,909 Mason Aug. 12, 1958 2,862,690 Mason Dec. 2, 1958