US2613102A

US2613102A - Pneumatically operated elevator bail

Info

Publication number: US2613102A
Application number: US200774A
Authority: US
Inventors: Claude M Roberson
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-12-14
Filing date: 1950-12-14
Publication date: 1952-10-07
Anticipated expiration: 1969-10-07

Description

Oct. 7, 1952 c. M. ROBERSON PNEUMATICALLY OPERATED ELEVATOR BAIL 4 Sheets-Sheet 1 Filed Dec. 14, 1950 llll III

all

QT TORNEYS Och 1952 c. M. ROBERS-ON 2,613,102

PNEUMATIC'ALLY OPERATED ELEVATOR BAIL Filed Dec. 14, 1950 4 Sheets-Sheet 2 IIII'A J W INVENTOR.

5 w, aim "a Oct. 7, 1952 c, M, RQBERSON 2,613,102

PNEUMATICALLY OPERATED ELEVATOR BAIL Filed Dec. 14, 1950 4 Sheets-Sheet 5 was JNVENTOR. JJV E M. R ER N PKTORNEYS PNEUMATICALLY OPERATED ELEVATOR BAIL Oct; 7, 1952 c. M. ROBERSON Filed Dec. 14, 1950 4 Sheets-Sheet 4 7a A JNVENTOR.

mm z MR ER ON BY W WW ATTORNEYS Patented Oct. 7, 1952 PNEUMATICALLY' P BA ERATED ELEVATOR IL Claude M.R0berson, Shreveport, I Applicationv December 14, 1350, Serial No. 200,774

13 ,Qlai1ns. (131,294582) This invention relates to apparatus for operating by pneumatic means elevator bails used in conjunction with hooks to. support pipe stands employed in oilwell drilling apparatus. 7 H

The most commonly used apparatus for drilling oil wells is the rotary drilling rig. This rig employs a derrick mounted over the well site which supports the drill stem and swivel during the drilling operation. A book. assembly supported by a vertically-movable travelling block is used to support a rotary swivel,- in which is positioned the uppermost section of the drill stem. The drilling pipe within. the well is attached to this uppermost section of the drill stem and means are provided; to effect rotation of the drill stem. The drill stem-.is composed of a plurality of sections of drill pipe connected tov gather by threaded collars or tool joints, a drill collar and a rotary hit all connected together and extending down into the well bore. V,

During the operation of drilling-an oil well, or the like, it is necessary to add sections of pipe to the drill stein as the bit progresses deeper into the earth. To facilitate this operation several sections of pipe are connectedtogether to form a pipe stand, an appropriate numberof pipe stands are stored in a convenient position, usually under the derrick, with their uppersections extending up to a platform. in thederrick above the derrick floor called a "safety? platform. When pipe is to be added. to the drillstem, an elevator apparatus, suspended from thehookby elevator bails, is latched about one of thestands of pipe, The stand is then lifted from its storag position and aligned with the drill stem, the stem then being rotated to engage the, stand with the drill stem. The elevator is then unlatched from the pipe and, if more pipe is to be attached to the stem, the elevator is returned to the safety platform where it is once more latched about a pipe stand and the stand lowered into engagement with the drill stem. Again the stand is connected to the stem, the elevator unlatched and, if the stem is now of proper length, the drilling operation is resumed. i

It is also sometimes necessary to change the bit during the drilling operation. To do this, step slips or wedge devices are inserted in the rotary bushing to hold the drill stem and the swivel is removed from the hook. The elevator apparatus is then lowered below the uppermost tool joint of the drill stem Where it is latched about one of the pipe sections with the upper surface of the elevator bearing against the upper surface of one of the tool joints of the drill stem. The wedges are then removed and theelevator apparatus raised by upward movement of the travelling block till a desired length of the drill stem is above the rotary table. The wedges are reinserted, the stand of pipe above the rotary rotated to disengage the parts of the proper tool ing the elevator bails joint, and the pipe stand which is to be disconnected from the stem swung away from the rotary to ;the storage position. wThe elevatorv is then unlatched and again lowered into position to again engage a pipe section. Once more the elevator is, latched, theistem raised and a length of; pipe disconnected from the stem. These operations are repeateduntil the bit is above ground, whereupon the bit is changed and the necessary number 0f pipe stands attached to the stem. by operations the reverse of those describedqabqve until the bit is again at the bottom of the well. Under the method of operation now in use for attaching and detaching the elevator from the drill stem, thehook is lowered until the elevator is at a proper distance above the floor of the derrick,.when the workmen on the derrick floor reachupwardly and push the elevator bails away from the drill stein as the elevator travels downwardly so that it will clear-theuppermost tool joint of, the drill stem during its downward travel When-the elevator-is detached from'the drill stem, the workmenpush the. elevator: bails away fromtheir neutral positions to allowthe elevator to clear the tool joint and to give theelevator a swinging motion so that it will reach the derrickman at the'proper' position when-the travelling block is raised to the; safety platform. Both of these operations are dangerouswoworkmen and-are relatively slow. 1 i The' present invention provides meansfor mov- I opposite directions from their neutral positions duringdownward and upward'inovement of the elevator under controlo'f a "sihgle operator, who maybe located advantageously at a location remote from the drill stem, to facilitate attachment and detachment of the elevator to and from the pipestand. With the apparatusv of this invention, danger to were h is avoided and operations are speeded up. 'The elevator bail operating" device of, the present invention comprisesalfhiid-operated re ciplooating piston which operates actuating means to iiiove therelevator bails andthe elevator onefoftwo directions away from their neutral positions, depending upon which way the piston is moiiedrfromjits neutral position Application of can; to operate the piston is controlledhy an operator, preferably at a remo'telocation, and apparatusis provided to automatically. reverse thedirection of movement Ofxth'e eleva'tonan'd elevator bails upon successive movement thereof.

- If fluid Weresupplied apparatusdirectly from, a: remote source, a long fluid linein the vicinityof the hook would be necessary and danger of 'entangleme'ntof the line would be present whenthe' hook was rotated. To avoid thisundesirable arrangement, the pre'sent invention provides for connection ofthe fluidsupply line to the'top'of the hook to. the bail-swinging body. The fluid for operation of the bailswinging apparatus is I through the hook body to a'point adjacent the location of the bail-swinging apparatus, from which it is transmitted directly to the inlet of the apparatus. The possibility of entanglement of the line is thus eliminated because, though the hook is rotated during the drilling operation, the hook assembly is so designed that the hook body, through which fluid passes, is not rotated.

The invention will be further describedwith reference to the accompanying drawings which illustrate a preferred embodiment thereof. However, the invention is not to be considered as limited to the apparatus specifically shown and described, but only by the scope of the appended claims.

In the drawings:

Fig. 1 is a diagrammatic perspective view. of part of the apparatus used in oil well drilling,

Fig. 2 is a side elevational view, partly in section, of the hook assembly used in a rotary drilling rig, showing the elevator bail operating mechanism of the present invention, I

Fig. 3 is a front elevational view of the hook of Fig. 2,

Fig. 4 is a sectional view showing the fluid cylinder and the automatic valve apparatus of the elevator bail operating mechanism, and

Fig. 5 is a sectional elevational view of the hook body of a modified'form of the hook assembly of Fig.2.

A rotary drilling rig for use in drilling oil Wells and the like is suspended from the upper end of a derrickl extending a substantial distance above a well site which is located beneath a floor 2. On the floor 2 is mounted a rotary table 3, through which the drill stem 4 passes into the well. The drill stem comprises a plurality of pipe sections connected by tool joints 5 and extends from above the rotary table to a point adjacent the bottom of the well bore. To the lowermost pipe section is attached a bit (not shown) which is adapted to cut the earth, rock, etc. through which the well is to be drilled. Rotarymovement is imparted to the rotary table 3 by power apparatus (not shown) called the draw works. Rotation of the rotary table 3 causes rotation of the drill stem 4, and consequent rotary movement of the bit.

The drill stem 4 is supported during the drilling operation by a hook assembly 6 composed of a hook 6a. and a hook body 62). The hook body 6b is suspended from a travelling block 1 by a ball 8 connected to a pair of ears 9, 9' at the top of the hook body. The travelling block 1 is movable vertically within .the derrick by adjustment of the length of a drill line [0 which passes over a plurality of sheaves within the travelling block and another set of sheaves in an upper crown block H suspended from the top of the derrick.

An elevator l2, used to encase a section of drill pipe and supportit during its movement toward or away from the drill stem is supported from the hook by a pair of elevator bails I3 and I3. Fluid-operated apparatus is provided to move this elevator away from its neutral position, as hereinafter described. A plurality of fluid conducting lines I la, 14b, 14c and [4d are led from an external source of fluid (not shown) to a bank of controls 15 at the drillers station on the derrick floor, and thence passed downwardly 4 to the hook body SD for purposes to be later explained. l

The derrick is. provided with a platform It at a substantial distance above the derrick floor on which the derrickman is stationed and from which he latches and unlatches the elevator l2 to and from the pipe sections above the floor.

Referring to Figs. 2 and 3, the elevator bails l3 and I3 have eyes l1, l1 at their upper ends which are fitted over and supported by arms l8, 18' extending outwardly from the side of the hook to. The eyes I1, 11' of the elevator bails are retained on their arms l8, I8 by links l9, I9, each connected at one of its ends to the outer end of the corresponding arms l8, l8 and connected at the other of its ends to the outer end of corresponding arms 20, 2D projecting from the side of the hook and spaced longitudinally from arms l8, Hi. This construction holds the elevator bails satisfactorily. yet allows free swinging of the bails to the positions A and Bshown in dotted lines in Fig. 2.

A vertically-extending fluid cylinder 2| is mounted on the hook 6a and has a fluid-operated piston 22 reciprocable therein. Two ports 23a, 23b, one at each end of the cylinder 2|, are provided through which fluid may be selectively supplied to move the piston 22 selectively in one direction or the other, as will be hereinafter more fully described.

A piston rod 24 is connected to the piston for reciprocating movement therewith and carries at its outer end a clevis 25, which is connected to a sleeve 26, fitted about a cross bar 21. The opposite ends of the cross bar 21 are connected to the upper ends of links 28 and 28'. The lower ends of the links 28 and 28' are connected to theouter ends of arms 29 and 29' of bell crank levers 30 and 30, pivoted at 31 and El. Each of the

other arms

32 and 32 of the bell crank levers extends downwardly alongside of one of the bails l3, l3. The lower end of the arm 32 is provided with a pair of spaced, outwardly-extending

operating fingers

33 and 33a positioned,'respectively, at the opposite sides of, and closely adjacent the elevator bail l3, and the lower end of the arm 32' has a corresponding pair of operating

fingers

33 and 33a.

Movement of the piston 22 within the cylinder 2| in the upper direction by admission of fluid under pressure to the lower port 23a will cause the piston rod 24 to move the cross bar 21 upwardly. The cross bar 21, through the links 28' will cause the bell crank levers 3B, 30 to move in a counterclockwise direction about their pivot pins 3i, 4|. Each of the operating fingers 33, 33' will then engage the left side of each of the elevator bails l3, 13', as viewed in Fig. 2, forcing each bail in the counterclockwise direction to position A. When it is desired to return the bails to their normal or neutral position, the fluid pressure is released. The weight force of the elevator and its bails will cause the return of the bails to their neutral positions, and. the consequent movement of the bell crank levers in the reverse, or clockwise direction will return the piston 22 to the center of the cylinder 2 I.

To move the elevator bails l3, 13' to position B, fluid under pressure is admitted to the upper port 23b of the cylinder 2!. The piston 22 and the piston rod 24 will then move downwardly and lower the cross rod 21 and the

links

28, 28. The lowering of the links will cause the bell crank levers 30, 30', to rotate about their respective pivots 3|, 31', in a clockwise direction to bring Munoz the respective'operating-

flngers

33a, 33a" into onagement with the other sideof each oftheelevator bails l3, l3", to move thebails toposition B. Return of the elevator and its bailsto'their neutral positions is effected by releasing the fluid pressure as before, whereupon the piston 22 returns to its neutral position. a

Control over the ports 23a and 231), through which the fluid is supplied tothe cylinder '2.l,'l's provided by the automatic valve'assembly, generally indicated at 3'4 and shownin detail in Fig. 4. This valve assembly comprises abylindrical valve body 35 mounted on the hoolc in and three quick-opening

valves

36, 36a and 36b, whichare mounted, respectively, one at a side of thelv'alve body 35 and the others at the opposite ends thereof. The quick-openingvalve 36'h'as three

ports

31, 38 and 39, which provide access to the inner chamber 49 of the valve and the valves 36a and 33b have corresponding ports denoted .by the suflixes a and b, respectively, to provide access to the inner chambers 40a and'40b. The side ports, 31, 31a and 31b of

valves

36, 36a and 36b, respectively, are the ports through which fluid is supplied to the valves. The opposite side port 38 of valve 36 is plugged, but the corresponding ports 38a. and 38b of valves 36a and 36b respectively, are connected to passages throughbppm site ends 4| and 42, respectively, of the valve body 35 which communicate with a cylindrical chamber 43 within the valve body.

The lower port 39 of the valve 33 is connected directly to an inlet passageM in the valve body 35 which communicates with the cylindrical chamber 43 therein. The lower port 33a of the valve 36a is connectedby a section of flexible tubing 45a to the lower port 23a of the fluid cylin der 2!, and the lower port 39b of the valve 361) is connected by a section of flexible tubing 45b to the upper port 23?) of the fluid cylinder.

A piston valve 46' is positioned in the cjylindri cal chamber 43 of the valve body 35. The piston valve 46, for the greater portion-of its length, is of less diameter than the diameter of the cylin drical chamber 43, and has lands 4! at its center,

and 41a and 41b at opposite ends'thereof. Each of these lands is of a'diameter suchtliat it'fits closely within the cylindrical chamber 43 and prevents fluid from escaping from oneof its sides to the other. The piston valve 46 is'of less length than the cylindrical chamber Within which it is positioned and is so constructed that when its land 41a is at the .end 4| of the cylindrical chamber 43, communication is established through the chamber between the inlet 44 in the upper wall thereof and an outlet 48athrou'gh the wall of the chamber. a w

When the land 47b is at the end 42 of the chamber 43, communication is established between the inlet 44 of the chamber and an outlet 48;; through the opposite wall of the chamber.

A section of flexible tubing Maconnectfe the outlet 48a of the chamber to the inlet port 31a of the valve 36a and a section of flexibletubing 49b connects the outlet 48b of the chamber'to the inlet port 371) of the valve 332).

An exhaust port 500 is located aft-one side of the chamber 43 in such position. that communication is established between the end 41' of the valve body 35 and the exhaust. port-When the land 4112 of the piston valve; 46 is moved to the end 42 of the valve body. A second exhaust port 501), at the other end of the valve bodyris so located that communication is established between the end 42 of the valve body and the exhaustport 50b when the land 41a of the piston valve is moved to'theend 4 I of thevalve body.

The

quickeopenin'g valves

36, 36a and 36b have double-acting valve members 5|, 5m and 5H), respectively, intheir respective inner chambers 40,431; and "4011- The valve members are normally'urged by springs 52, 52a and 52b, respectively, to bring one side of each valve member against. corresponding seats 53, 53a and 53b surrounding the

inlet ports

37, 37a and 37b to prevent 'oommunicationbetween the inlet ports and the chambers of the valves. However, when fluid under pressure is conducted to-any one of the inletports of the

valves

36, 36a and b, the corresponding valve memberis displaced from its normal seat. by the;force of the fluid, and the opposite side of the valve member is urged against the force of its spring against a. correspending seat 54, 53a or 54?) surrounding the corresponding port 38, 38a or 38b of the corresponding quick-acting valve,.t'o allow fluid to enter throughithev inlet port to the chamber but to prevent fluid from exiting from the chamber through the corresponding outlet :port 38, 38a 0'1'38b... i I

The operation of the automatic valve apparatus is as follows: With the piston valve 46 in the position's'howmwhen fluid under pressure is=conducted to thelnlet ort 31. of the valve 3 the valve member 5! thereof will be forced away from its normal seat 53 against its seat 54, allowing the'fluid to pass into the chamber 40 of the valve and through the outlet port 39 into the chamber 43 of the valve body 35. Since the land 4'! of the piston valve 46 prevents communication with the outlet 48b and the exhaust port 50a and the land 41b prevents communication with the exhaust port 5017, the fluid entering the valve chamber will be conducted through the outlet 48a and the flexible tubing 49ato the inlet port 31a of the valve 36a. The fluid will there press the valve member 5 la away form its normal seat 53a surrounding its inletlport 3'la to allow the fluid to pass into the chamber 40a of the-valve and through the lower I port 39a and the flexible tubing 45a to the lower port 23a of the fluid cylinder 2|.

The piston 22 will then be moved upwardly in the fluid cylinder 2| and will cause movement of the elevator bailsl3, l 3' to position A.

When the elevatorbails are to be returned to their neutral positions; the fluid pressure is turned off; The valve member 51a of the valve 3.6a will then'be returned to its normal position by its spring 5211 to close the inlet port 31a of the valve. The weight of the elevator bails and the elevator will swing the elevator bails to their neutral positions, thuspushing the piston rod 24 and the piston 22 downwardly to their normal positions in the cylinder 21. This downward movement of the piston 22 will force the fluid below it out of the lower port 23a of the cylinder through the port 39a and into the chamber 43a of. the valve 36a. Since the valve member 5m closes the supply port 31a at this time and communication is had between the chamber 43a and the port 38a, the fluid will exitfrom the valve 36a into the end 4| of the valve chamber 43, forcingthe piston valve 43 away from the end it to the end 42 of the valve chamber. The fluid will then be exhausted into the atmosphere through the exhaust port 50a of the valve chamher. The automatic valve apparatus is thereby set up to 'move the elevator bails to position B the next time the fluid pressure is .turned on.

' l When fluidis next supplied to the valve 33, the

7 valve member |v will again be forced off its seat 53 onto its seat '54, thus allowingthe fluid to pass into the chamber 40 of the valve and from thence through the port 39 and the inlet passage 44 of the valve body 35 into the chamber "43 of the valve body. Since the land 41 of the pistonvalve 46 is now at the other side of. the passage from that shown in Fig. 4, the fluid will exit from the chamber 43 through the outlet 4817, rather than the outlet 48a, as previously. The fluid passes from the outlet 48b through the flexible tubing 49b to the inlet port 31!) of the valve 362), where it will force valve member'5lb off its seat 53b and onto its seat 54b, thus allowing the fluid to enter the chamber 401) of the valve. From the chamber 401) the fluid passes through the tubing 45b into the upper port 231) of the fluid cylinder 2 I. The piston 22 will then be moved downwardly in the cylinder to cause movement of the elevator bails l3, I3 to position B. I

When the fluid pressure is again released, the weight of the elevator and the elevator bails will cause their return to their neutral positions, thus forcing the piston 22 to move upwardly to its normal position. The fluid compressed by this upward movement of the piston 22 will exit through the port23b of the cylinder and pass through the tubing 45b to the port 3% of the valve 36b. Since the fluid pressure supplied to the port 311) of the valve has beenremoved, the spring 5% will return to the valve member 512) to its seat 53b, thus allowing the fluid entering the valve through the port 3912 to pass through the valve and into the end 42 of the valve chamber 43. The fluid then forces the piston valve 46 away from the end. 42 of the chamber to the end 4| and exits to the atmosphere through the exhaust port 50b of the chamber. At this time, the valve assembly is once more prepared to provide for movement of the elevator bails to posi-'- tion A upon the next application of fluid-pressure to the assembly.

The walls of the book body 6b form a cylindrical chamber 55 within which a fluid-operated piston 56 is positioned. At the lower end of the chamber 55, the wall of the hook body extends inwardly to form a shoulder 51 which'supportsa bearing member 58 within the chamber.

During use of the hook assembly, it is frequently necessary that the hook 6a be rotated to effect engagement or disengagement of thexthreaded tool joints 5 connecting the sections of the drill stem. Since rotary movementof the hook body 6b would cause entanglement of the drill line ID, the hook is supported by the hook body for rotary movement relative thereto. For this purpose, upper and lower bearing plates 59a and 59b are provided to separate the bearing member 58 from the shoulder 57 and ball bearings 60 are inserted between the bearing plates'to allow the bearing member to rotate with the hook 6a relative to the hook body.

A piston rod 6| has a tapered portion 6 I a which extends within an upwardly converging bore through the piston 56. The upper end of the piston rod 6| projects above the piston 56 and'is threaded to allow engagement with a nut 62 which secures the piston to the piston rod. The lower portion of the piston rod extends through a bore in the bearing member 58 and is threadedly, or in other suitable manner, secured to the hookfia. A bearing collar 63 is pinned to the piston rod 6| between the hook to and thehookbody 6b to limit the upward movement of the hook.

Fluid under pressure. from an external source 8 (not shown), for movement of the piston, is transmitted through the fluid line [4a into the cylindrical chamber 55 adjacent the upper side of the bearing member 58. Y

A small clearance is provided between the bearing member and the inner wall of the hook body so that the fluid can communicate with the lower side of the bearing member. Consequently, the pressure exerted on the upper surface of' the bearing member is lower than that which would exist if the bearing member were closely fitted against the wall of the hook body. Thus, the tendency for the bearing member to jam against the hook body and resist rotation is reduced. Sealing packing 64 is positioned between the piston rod 6| and the bearing member 58 and between the bearing member and the wall of the hook body to prevent fluid from escaping from the cylindrical chamber 55. The packing is held in position by a plate 65 bolted to the under side of the bearing member 58 and rotatable therewith.

When fluid under pressure is supplied through the line Mo to the chamber 55, it exerts an upward force on the piston 55, tending to move the piston upwardly to the position shown in the drawings. That force will be transmitted to the hook through the piston rod 6|. Since the elevator I2 is supported by the hook through the elevator bails l3, I3, such upward force will be transmitted to the elevator and the pipe section which it holds. The lifting force can be controlled by adjustment of the fluid pressure to raise the pipe stand held by the elevator at the proper moment when the tool joint connecting that stand to the drill stem is disengaged.

During the use of the hook assembly, it is desirable at times to restrain the hook against rotation. To that end, a fluid-operated stop may be provided within the hook body 61), as shown in my Patent No. 2,519,288, to allow this control. To supply this stop with fluid, the fluid conducting line I4b is led from the source of fluid under pressure to the control position I5 and then to the fluid-operated stop within the hook body. With this arrangement the driller can prevent the rotation of the hook from his position on the elevator floor, without the necessity of touching the hook.

Fluid for the operation of the automatic valve apparatus and the consequent displacement of the elevator and elevator balls is supplied from an external source (not shown) through the fluid supply line [40 to the inlet of a connection block 66, bolted to a cap 61 at the top of the hook body 61). A fluid supply tube 68 has one end extending through the cap 61 into communication with the outlet of the connecting block 66 and extends therefrom downwardly into a passage 69 extending longitudinally within the piston rod 6|. The fluid supply tube is telescopically mounted within the passage 69 so that the piston 56 may slide longitudinally of and relative to the fluid supply tube and the tube is located centrally of the piston 56, so that the piston and piston rod may rotate relativeto the tube. The fluid supply tube is of such length that its lower end terminates adjacent the lower end of the passage 69 when the piston is in its upper position.

' A smaller passage 10 communicates with the lower end of the passage 69 and extends downwardly therefrom within the piston rod 6| to apoint adjacent the bearing collar- 63. A fluid pipe H communicates. with the lower end of the passage ill in all positions of the. hook and ex;- tends outwardly through the collar 63.. The other end of the pipe H is connected to the supply port of the quick-acting valve 36. A sealing gland I2 is positioned in the upper end of the large passage 69 between the piston rod SI and the fluid supply tube li8to prevent the escape of fluid from the passages in the piston rod to the cylindrical chamber 55.

The operation of the apparatus described will now be explained. When it is desired that the elevatorbails be moved to position .A to swing the elevator away from its normal positiomfluid under pressure is admitted through the fluid supply line Me to the fluid tube 6.8 from which it passes byway of the passagesBB and 1.0 to the valve 36 of the automatic valve apparatus 34. From valve 36, the fluidis transmitted to the port 23a of the fluid cylinder 24', causing the piston 22 to move upwardly and :swing the e1evator bails to position A.

When the elevator is tobelatched about the pipe joint, the fluid pressure is releasedwhereupon the weight of the elevator and elevator bails swings them to their normal positions. As explained above, the piston valve 45. will change its position at this time to prepare the automatic valve apparatus for its next operation.

After the elevator has been unlatched from the pipe joint, the elevator and elevatorbails are swung to position B by again 'apply'ingfluid pressure, at the control position 15, to the fluid line Mo to cause the apparatus. to functionas earlier explained toswing the elevator away from the tool joint of the pipe section to permit upward movement of the elevator past theytool joint. The fluid pressure is then once morereleased and the elevator anditsbailscagain returned to their normal positions. .During this movement, the piston valve 45 is shifted to the other end of the chamber 43 .to a positionto supply fluid to the lower port 2'3'a 'of the fluid cylinder when the-pressure is next applied.

In Fig. 5, there is shown armodifled connection between the fluid supply line-"and the automatic valve apparatus. Ratherthanbeinggkattached to the inlet of a fluid connection'block, the fluid lines I lcand Md are connected to a pair of vertically-extending pipesl3, 13! which are welded, or in other suitablemanner, attached to the cap of the hook. body. Awsectio'n of flexible tubing 14 is. connectedhat'one end to the lower end of in pipe Band has its. other end connected to the central inlet connection T5 of a known type of fluidc'onnection'1s6;.-called a double rotorseaL. which provides for fluid communication between a rotatable. element, here the piston rod 6|", anda non rotating element, here the flexible tubing 1:4. Another. section of flexible tubing 14" connects the pipe 13 to the outer inlet connection 15. of the' rotorseal. The double; rotorseal 'isibol'ted to the nut 62 at the top of the piston rod; I

The outer inlet 15' of the double rotor-seal communicates with a passage 69 in the piston A pair of sealing rings are positioned between the. fluid tube 11 and the walls defining the passage 69 below the juncture of the-passage 69' and the passage. 18, to prevent fluid from the passage 69' from entering the automatic valve apparatus.

The tube. 1''! terminates just below these sealing rings, and fluid from the tube ,fiows through a smaller passage Bl which extends outwardly to the Wall of the piston rod, where it is connected to a fluid conducting pipe 'll' which extends through the bearing collar 63' and conducts fluid to the automatic valve mechanism, as described above.

As with the apparatus of the previously described embodiment of the invention, the. piston rod of the apparatus shown in Fig. 5s1idesupwardly and downwardly about the tube 11 with out moving-the tube. The doublerotorseal" also makes it possible to rotate the piston and piston rod with the hook without rotating the tube.

The embodiment of the invention shown. in Fig. 5 is, adapted for use with hooks provided with a fluid-operated hook latch mechanism such as is described in my application Serial No. 190,516, filed October 16, 1950-, to selectively open and close the bail-receiving notch of the hook. Fluidconducting tube Md conducts fluid for the operation of this latch mechanism to the hook body. This fluid passes through the double rotorse'al," the passage 69', and thepassage 18130 th latchoperating mechanism (not shown).

It will be obvious that many further changescould be made in the apparatus herein, shown and described without departing from. the scope of the invention, as defined in the attached claims.

I claim:

1. A hook assembl-yior oil well drilling comprising a hook, a. hook body, an elevator-supporting bail supported by sai.d, hook for swinging movement, and meansv carried by the hook ass.emklcgly1 and connected tothe bail for swinging said 2. A. hook assembly for oilwell' drilling comprising a hook, a hookbody, an elevator-supporting bail supported by said hook for swinging movement from a neutral position, means connected to said bail and operable by fluid under pressure to-swing said ball away from its neutral position, and meansfor supplying fluid under pressure to said means operable'by fluid under pressure.

3; The apparatus defined in claim 2 in which the means operable by fluid under pressure comprises a fluid cylindena piston reciprocable within said cylinder, means engaging the elevator bail movabletto swi 'g the bail away from its neutral position, and means connecting the piston to the means engaging the elevator bail andoperable upon movement of the piston to move the means engaging the elevator bail, the means for supplying fluid under pressure'being connected to, the fluid cylinder, whereby supply of fluid under pres- Sureto the fluid cylinder will cause movement of the pistonto move the-means engaging the elevator bail and thereby swing the elevator bail away from its neutral position.

4. The apparatus defined in claim 3 inwhich the means; engaging the elevator bail comprises an operating finger positionedadjacent-one longitudinal'edge of the bail, and-said means connecting the piston to the means engaging the/elevator bail comprises a piston rod connected; to the piston for movement therewith and abell crank lever pivotally mounted-on thahook; with one arm-thereof soconnected-to thepistonrod,

11 and the other arm to the operating finger that movement of the piston causes pivotal movement of the bell crank lever and of its associated operating finger to 'move the elevator bail away from its neutral position.

5. In a hook assembly for oil well drilling comprising a hook, a hook body, an elevator and a pair of elevator bails supported on said hook for holding said elevator, a fluid cylinder, a piston reciprocable within said cylinder, means operably connected to said piston and movable by movement of the piston in one direction to cause movement of the elevator bails in one direction away from their neutral positions and movable by movement of the piston in the opposite direction to cause movement of the elevator bails in another direction away from their neutral positions, and means for selectively supplying fluid under pressure to the opposite ends or said fluid cylinder.

6. The apparatus defined in claim in which the movable means for causing movement of the elevator bails comprise two pairs of operating fingers, one pair embracing each of the elevator bails. 1

'7. The apparatus defined in claim 6 in which the movable means for causing movement of the elevator bails further comprise a pair of ball crank levers pivoted on the hook, one arm of each bell crank lever carrying a pair of said operating fingers, the other arm of each bell crank lever being operably connected to the piston for pivotal movement of the bell crank lever upon movement of the piston.

8.-The apparatus of claim 5 in which the means for selectively supplying fluid under pressure to opposite ends of the fluid cylinder comprises a valve body having a longitudinal chamber therein, means for conducting fluid under pressure to said chamber, a first means for conducting fluid from the chamber to one end of the fluid cylinder, a second means for conducting fluid from the chamber to the other end of the fluid cylinder, means in said chamber movable from a position allowing communication between said chamber and said first means and blocking communication between said chamber and said second means to a position blocking communication between said chamber and said first means and allowing communication between said chamber and said second means. and means for moving said movable means from one of its said positions to the other.

- 9. The apparatus of claim 5 in which the means for selectively supplying fluid under pressure to opposite ends of the fluid cylinder comprises a valve body having a longitudinal chamber therein, a piston valve reciprocable within said longitudinal chamber and having a land on each of its ends and a third land intermediate its ends, said lands closely fitting within the inner wall of said valve chamber, a main supply inlet and a pair of main supply outlets, one on each side of the inlet of the valve chamber, the inlet and outlets and said third land of the piston valve being so arranged that the inlet communicates only with the first outlet in one position of the piston valve and only with the second outlet in another position of the piston valve, means for admitting fluid under pressure to the inlet of said valve chamber, means for connecting said first outlet to one end of the fluid cylinder when the piston valve is in said one position, means for connecting saidsecond outlet to the other end of the fluid cylinder when the piston valve is in said other position, and means for moving said piston valve from one of said positions to the other when the elevator bails return to their neutral positions, whereby the elevator bails are moved from their neutral positions in one direction upon one applicationof fluid under pressure to the means for admitting fluid under pressure to the valve chamher and, after return of the elevator bails to their neutral positions, they are moved in another direction from their neutral positions upon the next application of fluid under pressure.

10. The apparatus of claim 9 in which the means for connecting the outlets of the valve chamber to the ends of the fluid cylinder compromise a pair of quick-acting valves each having an inlet and a pair of ports, one port being connected to one end of the fluid cylinder and the other port being .connected to one end of the valve chamber, said quick-acting valves each having a valve member yieldingly urged against its inlet and adapted to be displaced to close said other port when fluid under pressure is admitted to the inlet.

11. In a hook assembly for oil well drilling apparatus comprising a hook and a hook body, the hook body having a chamber therein, a fluid operated piston reciprocable within the chamber, a piston rod connected at one end to the piston and at its other end to the hook and an elevatorsupporting bail supported by said hook for swinging movement froma neutral position, means connected to said bail and operable by fluid under pressure to swing said ball away from its neutral position, and means for supplying fluid under pressure to said means operable by fluid under pressure, said fluid-supplying means comprising a passageway extending longitudinally within the pistonrod and a fluid-conducting tube mounted at one of its ends on said hook body and extending within said passageway, said tube being so arranged in said passageway that the piston rod is longitudinally and rotatably movablev with respect to the tube, said tube communicating at said one end with a source of fluid under pressure and at its other end with said fluid-operable means.

l2.'In a hook assembly for oil well drilling apparatus comprising a hook and a hook body, the hook body having a chamber therein, a fluid-operated piston reciprocable within the chamber, a piston rod connected at one end to the piston and at'its other end to the hook and an elevator-supporting bail supported by said hook for swinging movement from a neutral position, means connected to said bail and operable by fluid under'pressure to swing said ball away from its neutral position, and means including a conduit extending longitudinally within the piston rod for supplying fluid under pressure to said means operable by fluid under pressure.

13. Apparatus as defined in claim 12 in which said fluid-supplying means includes a pipe mounted on saidhook body, and means mounted on said pistonfor rotatably connecting one end of the pipe to one end of said conduit.

CLAUDE M. ROBERSON.

REFERENCES CITED lhefollowing references are of record in the