US3768663A

US3768663A - Control for well pipe racks and the like

Info

Publication number: US3768663A
Application number: US00188410A
Authority: US
Inventors: J Turner; Wormer R Van; J Walling
Original assignee: Byron Jackson Inc
Current assignee: Varco International Inc; Byron Jackson Inc
Priority date: 1971-10-13
Filing date: 1971-10-13
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30

Abstract

Control means for a well pipe rack and the like wherein a plurality of fluid pressure operated devices are sequentially operated. The pipe rack includes a finger board having horizontal arms defining spaces for receiving lengths of well pipe, and fingers are pivotally mounted on the arms and actuatable by fluid pressure between upright or open positions and horizontal or closed positions bridging the spaces between the arms to confine the lengths of pipe in place. The control includes a step-by-step operable mechanism for sequentially shifting a number of valves to one position as the mechanism is operated in one direction, the valves returning to an initial position when the mechanism is operated in the other direction. The rack fingers are sequentially opened and closed responsive to shifting of the valves between the two positions.

Description

United States Patent Turner, Jr. et al.

CONTROL FOR WELL PIPE RACKS AND THE LIKE Inventors: John W. Turner, Jr.; Richard A.

Van Wormer; James Bernard Walling, all of Houston, Tex.

Assignee: Byron Jackson, lnc., Long Beach,

Calif.

Filed: Oct. 13, 1971 Appl. No.: 188,410

Related US. Application Data Division of Ser. No. 47,057, June 17,

abandoned.

References Cited UNITED STATES PATENTS 11/1958 Seigle 91/36 X 5/1966 Royster 92/24 X Fuell et al....

Johnson et a Primary Examiner-Ramon S. Britts Attorney-Donald W. Banner et al.

[57] ABSTRACT Control means for a well pipe rack and the like wherein a plurality of fluid pressure operated devices are sequentially operated. The pipe rack includes a finger board having horizontal arms defining spaces for receiving lengths of well pipe, and fingers are pivotally mounted on the arms and actuatable by fluid pressure between upright or open positions and horizontal or closed positions bridging the spaces between the arms to confine the lengths of pipe in place. The control includes a step-by-step operable mechanism for sequentially shifting a number of valves to one position as the mechanism is operated in one direction, the valves returning to an initial position when the mechanism is operated in the other direction. The rack fingers are sequentially opened and closed responsive to shifting of the valves between the two positions.

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Sill-II OSDF 10 CONTROL FOR WELL PIPE RACKS AND THE LIKE The present application is a divisional application of Ser. No. 47,057, filed June 17, 1970, now abandoned.

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION In the drilling of wells, such as oil and/or gas wells, pipe racking equipment has been employed, whereby the stands or lengths of drill pipe and drill collars may be racked in vertical positions in finger boards in the derrick, during the drilling operations and during round tripping of the drill string.

Pipe racking finger boards generally comprise a plurality of horizontal arms disposed in parallel relation to form pipe receiving spaces, and fingers are pivotally mounted on the arms in spaced relation therealong, the fingers being actuatable between upright or open positions and horizontal or closed positions.

The present invention is generally applicable to the finger boards of pipe racking devices to control the opening and closing of the fingers in a selected sequence.

2. THE PRIOR ART The prior art is represented by the Finger Board and Racker Apparatus of US. Pat. No. 3,501,017, issued Mar. 17, I970, in the names of Johnson and Turner.

In such finger board apparatus, the fingers are actuatable between open and closed positions by pressure operated actuators connected to the respective fingers and controllable by solenoid operated valves, requiring the use of extensive and complicated electrical installations.

SUMMARY OF THE INVENTION The present invention provides a simple mechanical control for a plurality of valves which are to be sequentially operated, which eliminates the need for extensive electrical installations to effect sequential control of fluid pressure operated devices, such as the fingers of well pipe racking finger boards.

More particularly, the invention provides a step-bystep operable control system, including valve actuating means which is substantially in the nature of an escapement mechanism. The mechanism comprises a biasing means for biasing a valve actuating member in opposite directions, and an escapement or control member which is shifted with the actuator member but the movement of which is incremental and controlled by a releasable stop actuatable to a released condition and automatically engaging the escapement or control member to limit movement of the latter to one increment, in either direction. The valves are supported along the path of movement of the valve actuating member and are sequentially actuatable by the latter to one position as the escapement or control member moves in one direction and are sequentially reversely actuatable to another position when the escapement or control member moves in the other direction. These oppositely actuatable valves are adapted to control the flow of pressure fluid to actuator cylinders for rack fingers of a finger board in the illustrated embodiment of the invention.

The objects of the invention include the provision of easily installed and operable sequential actuator means for the fingers of pipe racking finger board apparatus, and the like.

This invention possesses many other advantages, and has other purposes which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a drilling ship having a derrick assembly, and including finger board apparatus exemplary of the present invention;

FIG. 2 is an enlarged side elevational view of the derrick assembly, taken on the line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary view showing in plan the finger board and a racking means of the racking apparatus, and taken on the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary top plan of an arm of the finger board of FIG. 3;

FIG. 5 is a side elevation of the finger board arm of FIG. 4, with parts broken away;

FIG. 6 is a detail view in vertical section, as taken on the line 6-6 of FIG. 5;

FIG. 7 is a detail view, as taken on the line 77 of FIG. 3, and with the housing removed to show in side elevation control apparatus made in accordance with the invention;

FIG. 8 is a top plan of the apparatus of FIG. 7;

FIG. 9 is an enlarged fragmentary vertical section, as taken on the line 99 of FIG. 8;

FIG. 10 is an enlarged top plan of the shiftable stop means for the control apparatus with parts broken away, showing the stop in one position;

FIG. 11 is a fragmentary vertical section, as taken on the line 1l11 of FIG. 10, showing the valve actuator at an intermediate position of travel stopped by the stop in the position of FIG. 10.

FIG. 12 is a fragmentary vertical section, as taken on the line 12-12 of FIG. 11;

FIG. 13 is an enlarged fragmentary detail in vertical section, as taken on the line 13-13 of FIG. 12;

FIG. 14 is an enlarged fragmentary top plan of the shiftable stop means for the control apparatus, with parts broken away, showing the stop in the alternate position from the position of FIG. 10;

FIG. 15 is a vertical section corresponding to FIG. 13, but showing the stop in the alternate position of FIG. 14;

FIG. 16 is a schematic diagram of the hydraulic control system;

FIG. 17 is an enlarged plan view of a remote control panel; and

FIG. 18 is a schematic diagram of an electrical operating system under control of the panel of FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, there is shown a drilling ship 21 afloat in the water, the surface of the water being designated 22. The ship has an elevated platform 23 positioned admidships. Erected on the platform is a drilling derrick 24. The ship has a moon hole 25 through which a drill string 26 extends from above the platform 23 into the water and thence into the earth (not shown) below. As this type of drilling ship with a platform and derrick is widely known in the field to which the invention pertains, it need not be described here in further detail.

The derrick 24 is shown somewhat schematically, sway braces, guy wires and similar structural members being omitted to enable working apparatus to be shown more clearly. The derrick has generally vertical corner posts 27 and 28 supported on the platform 23 on

base members

29 and 31. A water table 32 near the top of the derrick carries the usual crown block 33 which is aligned with the vertical center line of the derrick. Suspended from the crown block by cable 34 is a traveling block 35. As is usual, one end (not shown) of the cable 34 is anchored to the ships structure, and the other end is led to the spool 36 of a draw work 37 for raising and lowering thetravelling block traveling the load supported thereby.

A hook structure 38 is swingably suspended from the bottom of the traveling block 35 by inter-engaged bails 39 on the hook and 41 on the block. An elevator line 42 is swingably suspended from an ear 43 on the hook structure, and the link has an elevator 44 swingably attached by another ear 45 to the lower end of the link 42. A second elevator link (not seen in FIG. 2) on the other side of the hook structure 38 similarly connects the elevator 44 to the hook structure 38.

The general reference numeral 46 denotes apparatus for positioning and guiding the block and hook structure. An elevator link stabilizing device is designated by the general reference numeral 47. The general reference numeral 48 designates apparatus for supplying compressed air to the elevator 44 to actuate it.

A stand 49 of drill pipe is shown as being supported by pipe-handling equipment including an upper racker assembly 51 and an intermediate pipe supporting racker assembly 52. Other stands 53 of drill pipe or drill collars 54 are shown at rest in a pipe rack having a finger board 55, to be hereinafter described, a base 56, and an intermediate rack member 57. The upper end of the string of drill pipe 26 is shown projecting above the usual power tong 58, slips 59, and the rotary table 61. Casing manipulating apparatus is shown at 62. A swivel and kelly assembly 63 is disposed in the rat. hole 64. I

Projecting outwardly from the derrick and positioned under the racker 51 is a horizontal stage 65 upon which an operator may stand to adjust or repair the racker. Associated with the racker 52 is a cable 66 actuated by a fluid-powered piston-and-cylinder motor 67 for raising and lowering the head of the racker 52.

The apparatus generally described above is well known and particularly is adapted to rack drill pipe and drill collars in the finger board 55, the details of which are best seen in FIG. 3. The finger board 55 comprises a suitable frame structure including an outer rail 70 extending from side to side of the derrick and connected with end rails 71 extending horizontally in opposed parallel relation, as well as rails 72 extending towards one another from the end rails 71 and reinforced with suitable braces 73, thereby providing a rectangular frame having a central opening or space 74 between the ends of the rails 72. At opposite sides of the opening 74, each of the end rails 71 supports a number or horizontally extended, parallel rack arms 75 defining spaces 76 opening laterally from the space 74, whereby pipe stands may be moved laterally into and from the spaces 76 by the upper racker 51. I

The racker 51 comprises a horizontally extended racker arm 51a having a pipe engaging head 51b adapted to engage a stand of pipe such as the stand 49, and to move the latter into or from the finger board 55, as the arm 51:; is extended and retracted through a support 51c which forms part ofa carriage 51d which is laterally shiftable by a drive motor 51a in supporting tracks 51fwhich extend horizontally at one side of the derrick. Such movement of the racker arm 51a and the carriage 51d may be effected by the derrickman D, as seen in FIGS. 2 and 3, adapted to be seated at a control console adjacent to which is situated a universal control 51g for controlling the racker drive in a manner well known in the art. The racker 51 is controlled to move pipe stands into and from the spaces 76 between the rack arm so as to position such pipe stands between the arms 75 at locations at which the stands are to be confined in place by fingers 77 on the rack arms 75, which as will be hereinafter more fully described, are actuatable between horizontally extended, closed positions and upright, open positions. In general, such finger boards are well known and described in the aforementioned Johnson and Turner US. Pat. No, 3,501,017.

More specifically, as seen in FIGS. 4-6, each of the fingers 77 is pivotally supported between a pair of ears 78 on a pivot pin 79 carried by a canister 80 which extends vertically downwardly into he arm 75 and which is connected to the arm as by fasteners 81. Within the canister 80 is a double acting hydraulic actuator cylinder 82 having a rod 83 projecting therefrom and connected to a lever 84 formed as part of the finger 77, the lower end of the cylinder 82 being pivotally supported on a pin 83a, whereby the finger 77 is actuatable between an upright or open position and'a horizontally extended or closed position adapted to confine a pipe stand against significant lateral movement in the space 76 between the rack arms 75. Fluid pressure, as will be later described, is supplied to and exhausted from opposite ends of the cylinder 82 by conduits 82a and 82b.

Similar retainer fingers 85 may be provided at spaced locations along the outer rail 70 of the box frame of the finger board 55 for confining a suitable number of the drill collar stands 54, as seen in FIG. 3, and it will be understood that the fingers 85 will be actuated by actuator cylinders like the cylinders 82 which are operable to actuate the drill pipe retaining fingers 77.

In the use of the apparatus to rack drill pipe and drill collars in the finger board 55, it is necessary that the fingers 77 spaced along each of the arms 75 be sequentially operable between their opened and their closed positions, and that, preferably, the means for effecting actuation of these fingers between these positions be such that a given finger cannot be actuated to either position out of turn in the sequence of operations. Heretofore, electrical control valves have been employed for controlling the flow of pressure fluid to the finger actuating cylinders, involving substantial wiring,

and also involving the possibility that the

fingers

77 or 85 may be operated in an improper sequence, thereby inadvertently releasing a pipe stand or inadvertent failure to properly confine a pipe stand against movement.

The control means of the present invention, accordingly, involves the utilization of electro-hydraulic control means, generally designated at C, for effecting the step-by-step or sequential actuation of the fingers 77 of the respective arms 75, or the fingers 85, between their opened or closed positions. Illustratively, the control means C are located on the end rails 71 of the frame of the finger board 55, but if desired, the control means may be otherwise located. In addition, in the illustrative embodiment, the control means C are respectively operated from a remote location such as a control panel P operable by the derrickman D. Each of the control means C is essentially the same as the other, and a typical control means C is illustrated in FIGS. 7 through 15.

Referring to FIGS. 7 through 15, the typical control means C will be seen to comprise a suitable upright support 90, on which is mounted an upwardly extended tubular body 91. Reciprocable in the body 91 is an elongated stop or escapement rod 92 which extends through a releasable escapement stop means 93 suitably affixed on a supporting flange 94 at the top of the body 91. At its lower end, the stop or escapement rod 92 is connected by an adjustable screw connector 95 to the upper end of a cylindrical actuator 96 which extends vertically into the body 91. At its lower end, the cylindrical actuator 96 is connected by an adjuster screw 97 to a rod 98 of a double acting hydraulic actuating cylinder 99. At its lower end, the hydraulic actuating cylinder 99 is suitably connected, as at 100, to the base of the upright support 90. Pressure fluid is supplied to and exhausted from the opposite ends of the cylinder 99 via conduits 99a and 99b. Accordingly, it will be apparent that the actuator cylinder 99 is adapted to bias the cylindrical actuator member 96 in opposite directions and to correspondingly bias the stop or escapement rod 92 in opposite directions, under the control of the releasable escapement stop means 93.

Actuatable by the cylindrical member 96 is a number of valve assemblies V which are spaced vertically along and suitably supported on the body 91 in angularly staggered relation thereabout, so that there is one of the valves V on the body'91 for each of the

rack fingers

77 or 85, as the case may be. Each valve V comprises a body 101 from which extends a shifter rod 102 having a head 103 thereon disposed in an opening 104 in the body 91. A spring 105 acts on the head 103 to normally bias the latter in a direction such that the head 103 extends into the body 91 in the path of the cylindrical actuator body 96, so that when the actuator body 96 is moved upwardly it will sequentially engage the valve operating head 103 to successively actuate the valve rods 102 outwardly with respect to the body 91 and into the respective valve body 101. As will hreinafter be described in greater detail, the valves V are each preferably of a type which will, in one position, direct hydraulic fluid to a finger actuator cylinder 82 to open a finger and, in the other position, to direct fluid to the actuator cylinder to close the finger, so that the fingers will be positively opened or closed depending upon whether its valve V is in one position or in the other. The specific details of the valves V are not material to the present invention since many common available two-position valves may be employed.

As previously indicated, fluid under pressure is applicable to the bias cylinder 99 to actuate the cylindrical body 96 upwardly or downwardly to sequentially shift the valves V from the normally spring loaded position to the alternate position, and to allow the valve V to shift back to the spring loaded position, as the actuator body 96 moves upwardly and downwardly in the tubular valve supporting body 91. The escapement rod 92 and the releasable escapement stop means 93 are cooperatively adapted to allow incremental movement of the body 96 to progressive locations to actuate the valves V successively. Accordingly, the escapement stop rod 92 in the illustrative embodiment, as best seen in FIGS. 9 and 11, has on opposing longitudinal sides thereof a number of longitudinally spaced V notches 106 on one side of the rod and V notches 107 on the other side of the rod, as well as outstanding V lugs 108 located between adjacent notches 106 and V lugs 109 located between adjacent V notches 107. The spacing of the notches and lugs just described is such that a V notch on one side of the rod 92 is opposite to a projection on the other side of the rod 92. In addition, the Ion gitudinal space between

opposite notches

106 and 107, denoted by the dimension X in FIG. 11, is equal to the distance between centers of the successive actuators 103 of adjacent valves V, as indicated by the dimension Y in FIG. 11.

The releasable escapement stop means 93 is cooperative with the rod 92 and comprises a body section 110 secured to a base plate 11 1 as by fasteners 112, the fasteners 112 also securing in place a top plate 113. Formed in the body 110 is a T-shaped way 114 in which is reciprocably disposed a slide 115. The rod 92 extends vertically through the base plate lll, the body 110 and the top plate 113, intersecting the way 114 and extending also through an enlarged vertical opening 1 16 in the slide 115. Suitably provided on or connected to the slide 115 by fastners 1 17 is a pair of

opposed stop plates

118 and 119 spaced apart for passage of the rod 92 therebetween. The

plates

118 and 119 provide on opposite sides of the rod 92 opposed V-shaped

stop sections

120 and 121, respectively, the stop section 120 being engageable in the notches 106 at one side of the rod 92 and the V-shaped stop section 121 being engageable in the notches 107 at the other side of the rod 92, to hold the rod 92 against movement in either direction, depending upon the direction of the bias applied to the rod 92 by the bias cylinder 99. In order to allow an increment of movement of the rod 92 in either direction, it is necessary to shift the slide 115 in the way 114 in one direction or the other, depending upon whether the V-shaped

stop section

120 or 121 is engaged in a

notch

106 or 107.

Actuator means are provided to effect such movement of the slide 115 including a pin 122 carried by the slide 115 and extending upwardly into a clearance space 123 in the top plate 113. The pin 122 extends into a cam slot 124 in a cam plate 125 which is reciprocable in-a slot 126 extending in the top plate 113 at a right angle to the way 114. The cam slot 124 has a first portion 124a extending parallel to the line of movement of the cam plate 125 and a second portion 124b spaced and laterally offset from the slot portion 124a and also extending parallel to the line of movement of the cam plate 125. lnterconnecting the slot portions 124a and 1241) is an angular portion 1240, one angular wall of which will engage the cam pin 122 to move the slide 115 to the left, as viewed in FIGS. 10, 11 and 13, for example, when the cam plate 125 is in the position shown in FIG. 10, and the other angular wall of which will shift the slide 115 to the right, as seen in FIGS. 14 and 15, when the cam plate 125 is shifted to the other position as shown in FIG. 14.

- 130a and 130b, under the control of the valve means ECV, later to be described, which may be supported on the support 90 for the control means C, as seen in FIG. 7. Accordingly, actuation of the cylinder 130 in one direction will cause the slide 115 of the releasable escapement stop means 93 to be shifted in one direction to release it from the rod 92 on one side of the latter and engage it with the rod 92 on the other side of the latter.

As is best seen in FIGS. 13 and 15, the space between the apex of the projection 120 on the stop 118 and the opposed apex of the projection 121 on the stop 119 is slightly greater than the distance between the apex of the

projection

108 or 109 and the opposite apex of a

notch

107 or 106, as the case may be, a sufficient amount that when one of the

projections

120 or 121 is engaged in a

notch

106 or 107, the

other projection

120 or 121 is slightly spaced from the opposing

projection

108 or 109 of the rod 92. If, therefore, the bias is applied to the rod 92 by the cylinder 99 to move the rod 92 downwardly, as indicated by the arrows, movement of the rod 92 is precluded by engagement only between an upper face of a

V notch

106 or 107 and by the upper face of a

projection

120 or 121 on the

stops

118 and 119. However, as the stop slide 115 is shifted to release the rod 92 for an increment of downward movement, the

stop projection

120 or 121, due to its V shape, will allow progressive downward movement of rod 92 so that the underfaces of the

projections

120 or 121 will clear the upper face of the

adjacent stop projections

108 and 109, but downward movement of the rod 92 will be initially arrested by engagement of the superjacent downwardly moving

stop projection

108 or 109 on the rod 92 with an upper face of the

projection

121 or 120 on the

stops

118 and 119, before the

other projection

120 or 121 moves into a

notch

106 or 107.

It will now be understood that the control means C for each set of

fingers

77 or 85 of the finger board 55 will be essentially the same as that described above at both sides of the finger board, that is, both to the right and to the left of the central opening 74 leading to the racking spaces 76. Thus, the illustration and description of a system operable to operate all of the fingers on one arm at each of the opposite sides of the finger board will suffice, and in such system, since there is a plurality of fingers and respective valves V, it is unnecessary to show or describe all of the fingers and valves.

Thus, as seen in H6. 16, fluid may be supplied from a suitable source, such as a pump P to a conduit 200 v and thence to the inlet conduit 201 ofa left hand selecmeans C, only one of which cylinders 99 is shown, but ll of which may obviously be connected in parallel in the

conduits

205 and 206; and in the other position of the selector valve SVL the cylinders 99 will be actuated in the other direction. As a result, the cylinders 99 at the left hand side of the finger board are adapted to apply either an upward bias or a downward bias to the respective cylindrical actuators 96 for the finger control valves V. Correspondingly, the cylinders 99 of the control means C at the right hand side of the finger board are operable under the control of the selector valve SVR which has the illustrated alternate positions for reversing flow through

conduits

207 and 208 which connect the valve SVR to the bias cylinders 99 at the right hand side of the finger board, so that the rods 92 of the right hand control means C can be biased upwardly or downwardly.

Also connected to the source P via a conduit 210 and to drain by a conduit 211 are the actuator cylinders 130, at the left side of the finger board 55, the cylinders 130 at the right side of the finger board being connected to the source and to drain by

conduits

212 and 213, respectively, whereby the several releasable escapement stop means 93 of the control means C are reversely operable as previously described. In order to reverse the cylinders 130, an escapement control valve ECV is interposed between the respective cylinders 130 and the

conduits

210, 211 or 212, 212, at opposite sides of the system, such valves ECV being shiftable to either of two positions to reverse the direction of fluid flow to the cylinders 130, whereby to effect reciprocation of the respective cam plate 125 and thus the slide which carried the shiftable escapement stop 1 18 in each control means C.

As previously indicated, each of the valve V for controlling the application of pressure fluid to the actuator cylinders 82 for the respective fingers 77 are spring loaded to a normal position at which the fingers are down or closed, and the valves V are actuatable by the cylindrical rod 96 upon upward movement to shift the valves V to the alternate position to reverse flow of fluid to the cylinders 82, causing the fingers to be shifted to the upright or vertical position. Thus, as seen in FIG. 16, all of the valves V, only two of which are shown, at each control means C at the left side of the finger board are connected to the source conduit 210 and the drain conduit 211, and at the right side of the finger board are connected to the source conduit 212 and to the drain conduit 213.

Thus, it is apparent that, in operation, if a selected row of fingers is to be operated, either to open or close the fingers, it is necessary that either the left selector valve SVL or the right selector valve SVR be actuated in a desired direction to apply either an upward bias or a downward bias to the escapement rods 92 of the respective control means shifting of followed by shiftingof the appropriate escapement valve ECV to allow movement of the escapement rod 92 one increment to cause shifting of one of the escapement control valves in the direction to either open or close one of the finger control valves V.

The valves of FIG. 16 are shown as solenoid operated valves, but may be pressure actuated, depending on the type of operating system employed, but in either case, the system may lend itself to automation of the racking system. Assuming, for the sake of description, that the system is to be manually controlled by the derrickman D and that the valves are solenoid operated, a suitable 7 control panel may comprise electrical controls as seen in FIG. 17. The electrical system, functionally, may be as schematized in FIG. 18, wherein only a pair of the escapement control valves ECV have been illustrated at the right and left hand side of the system, but it will be understood that the number of such valves on each side corresponds to the number of control means C.

More particularly, it will be noted that a source of current is adapted to be connected either to the right or to the left side of the rack control system by an onoff switch 300 having a central off position and left and right positions as indicated by the legends for energizing the respective left and right sides of the system. On each side of the system is a conductor 301 to which current is supplied when the switch 300 is either in the left or right position, both sides of the system also being connected to a ground by a conductor 302. At the left hand side of the system, the selector valve SVL is in circuit with an up-down switch 303 which is the up position will energize a solenoid valve in one direction and when the down position, as indicated by the legends, will energize the solenoid valve in the other direction, whereby as previously described, fluid will be supplied in the selected direction to the bias actuator cylinders 99.

Each of the escapement control valves ECV, only two of which are illustrated in FIG. 18, is in circuit with a push button switch, respectively shown at 304 through 311, as seen in FIG. 17, and a realy R, wereby closure of a switch 304 through 311 energizes its realy R so that the solenoids at opposite ends of the values ECV are alternately energized to shift the valve successively in opposite directions. Such alternating relays are well known may include a timed holding circuit (not shown) as is obvious, so that the push button 304 through 311 need only be instantaneously engaged to energize its relay R and so that the push button switches need not be held closed. Since each successive closure ofa push button switch 304 through 31 1 effects reverse shifting of its escapement control valve ECV, it will be apparent that the slide 115 of the respective releasable escapement stop means 93 of the control means C will be alternately reciprocated to allow an increment of movement of the escapement rod 92, in a direction determined by the direction in which a bias is being supplied by the bias cylinder 99.

At the right hand side of the system, the selector valve SVR for the bias cylinders of the control means C at the right hand side of the finger board is in circuit with a selector switch 312 having up and down positions as indicated by the legends so as to cause the desired shifting of the valve SVR as previously described whereby to apply the desired bias to the control means C for each rack arm. As at the left side, each of'the escapement control valves ECV at the right side is also in circuit with a push bottom switch respectively designated 313 through 320 and an alternating relay R, whereby these valves ECV may also be alternately operated as described above.

In the use of the apparatus described above during the racking of pipe stands in the finger board 55, a pipe stand is engaged by the upper racker 51 and by the similar lower racker 52,'and the pipe elevated by the cable 66. Thereafter, the racker arms including the arm 51a is retracted until it is aligned with a space 76 between the rack arms into which the next pipe stand is to be moved. The carriage 51a is then shifted laterally to move the pipe stand into a desired position. At this time, the appropriate push button switch selected from the group 304 through 311 or from the group 313 through 320 is instantaneously depressed, while

appropriate switch

303 or 313 is in the down position, and the electro-hydraulic system will function as described above to close the next finger 77 in the selected row. To remove the same pipe stand froma rack position, it is only necessary to shift the switch 303 or the switch 320 to its up position and again depress the appropriate push button and the finger will be opened. Preferably, in order to assist in locating the spaces between the racked arms, the push button switches 303 through 31 1 and 313 through 320 and the fingers in the rows of fingers controlled by the respective switches are color coded.

From the foregoing, it will now be apparent that the present invention provides a controlled escapement, hydraulic system whereby a plurality of devices which are shiftable between first and second positions may be sequentially actuated from one position to the other. While the control has been illustrated and described with particular reference to and is ideally suited for its use in the actuation of the fingers of a pipe racking finger board, it will be understood that the system may be employed in other applications.

We claim:

1. ln well drilling derrick apparatus having a pipe racking finger board in the derrick, said finger board having a plurality of elongated arms disposed in horizontally extended parallel relation to define elongated spaces for receiving pipe stands, said arms having a plurality of finger members pivotally mounted thereon for movement between open positions and horizontally extended closed positions to confine a pipe in positions between said arms, a double acting fluid pressure operated actuator for each finger member, double acting valve means operable for respectively directing pressure fluid from a source to the respective actuators to operate the latter, spaced valve shifters associated with each of said valve means for operating the same, means for sequentially operating said valve shifters including a valve shifter operating member movable into successive operating relationship withsaid valve shifters, biasing means for moving said valve shifter operating member as aforesaid, and escapement means associated with said operating member, said escapement means including releasable means normally restraining move ment of said operating member and releasable to allow movement of said operating member, and stop means associated with said operating member and operable for limiting movements of said operating member to increments of movement corresponding to the spacing of said valve shifters.

2. Apparatus as defined in claim 2, wherein said stop means includes a first stop element connected to said valve shifter operating member and movable with the latter, a second stop element actuatable into and from engagement with the first stop element, and means for actuating said second stop element.

3. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member having spaced stop elements thereon, a second stop member having stop elements engageable with said stop elements on said first stop member, and means operable on said second stop member to shift the latter to effect engagement and release of the stop elements on said first and said second stop member.

4. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member including an elongated rod having stop elements spaced therealong, a second stop member having stop elements thereon, and means operable on said second stop member to. shift the latter to effect engagement and release of said stop elements.

5. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, a second stop member actuatable into and from engagement with the first stop member, said stop members including coengageable stop elements releasable when said second stop member is moved from engagement with said first stop member, and actuator means for said second stop member.

6. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, a second stop member actuatable into and from engagement with the first stop member, said stop members including coengageable stop elements releasable when said second stop member is moved from engagement with said first stop member, and actuator means for said second stop member, said biasing means adapted to move said first stop member in opposite directions.

7. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, said first stop member having alternate notches and projections spaced thereon at opposite sides thereof, with a notch on one side opposite to a projection on the other side of said first stop member, a second stop member having opposed stop projections, said second stop member being actuatable to move the stop projections thereon alternately towards and away from opposite sides of said first stop member to alternately engage one stop projection of said second stop member in'notches at opposite sides of said first stop member and to dispose the other stop projection on said second stop member for abutting engagement with a projection on said first stop member to position said one stop projection for engagement in a notch in said first stop member, and said biasing means adapted to move said valve shifter operating member and said first stop member relative to said second stop member when said stop projections on said second stop member are free of said notches.

8. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, said first stop member having alternate notches and projections spaces thereon at opposite sides thereof, with a notch on one side opposite to a projection on the other side of said firststop member, a second stop member having opposed stop projections, said second stop member being actuatable to move the stop projections thereon alternately towards and away from opposite sides of said first stop member to alternately engage one stop projection of said second stop member in notches at opposite sides of said first stop member and to dispose the other stop projection on said second stop member for abutting engagement with a projection on said first stop member to position said one stop projection for engagement in a notch in said first stop member, and said biasing means adapted to move said valve shifter operating member and said first stop member in opposite directions relative to said second stop member when said stop projections on said second stop member are free of said notches.

9. Apparatus as defined in claim 1, wherein said stop means comprises an elongated rod connected at one end to said valve shifter operating member, said rod having stop elements spaced therealong at opposite longitudinal sides thereof with the stop elements on one side spaced longitudinally from the stop elements on the opposite side a distance equal to the distance said valve shifter operating member moves to cause actuation of successive valve shifters, a slide having an opening through which said rod extends, said slide having stop elements at opposite sides of said opening alternately engageable with the stop elements on opposite sides of said rod responsive to reciprocation of said slide, and actuator means for reciprocating said slide.

10. Apparatus as defined in claim 9, wherein said actuator means for reciprocating said slide comprises a double acting fluid pressure operated actuator, and valve means for directing pressure fluid in alternate directions to said fluid pressure operated actuator to reciprocate said slide.

11. Apparatus as defined in claim 9, wherein said actuator means for reciprocating said slide comprises a cam plate shiftable in opposite directions at a right angle to the direction of reciprocation of said slide, cooperative cam means on said slide and said plate for reciprocating said slide upon movement of said cam plate in opposite directions, and actuator means for shifting said cam plate.

12. Apparatus as defined in claim 9, wherein said actuator means for reciprocating said slide comprises a cam plate shiftable in opposite directions at a right angle to the direction of reciprocation of said slide, one of said cam plate and said slide having a cam pin and the other of said cam plate and said slide having a cam slot having offset end portions and an angular intermediate connecting portion in which said pin is disposed for reciprocating said slide, and actuator means for shifting said cam plate.

13. Apparatus as defined in claim 9, wherein said stop elements on said rod comprise a plurality of alternate projections and notches on opposite sides of said rod, with each projection on one side opposed by a notch on the other side of said rod, and said stop elements on said slide comprise opposing stop projections alternately engageable with said stop projections and said notches of said rod.

14. Apparatus as defined in claim 9, comprising an elongated support for said valve shifters and said valve shifter operating means, said valve means comprising a plurality of two position valves having valve shifters spaced along said support, spring means biasing each of said valve shifters to one position, said valve shifter operating means comprising an elongated member shiftable longitudinally of said support and engageable with successive valve shifters upon movement of said elongated member to shift said valve shifters to a second position.

Patent No. 3:768:66?

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated October 30; 1973 Inventor(5) It is certified that error appears in the above-identified "patent and that said Letters Patent are hereby corrected as shown below:

Front page, Assignee's name "Byron Jackson, Inc. should be -Byron Jackson Inc.-- Claim 2, line 1, after "claim" cancel "2" and insert -l--.

Claim 8, 7 line 5; "spaces" should be --spaced--.

' Signed and sealed this 18th day of June 19714..

(SEAL) Attest:

. c MARSHALL mum EIMARD mmmwcrmh, JR.- Atteating Officer I I Commissioner of Patents

Claims

1. In well drilling derrick apparatus having a pipe racking finger board in the derrick, said finger board having a plurality of elongated arms disposed in horizontally extended parallel relation to define elongated spaces for receiving pipe stands, said arms having a plurality of finger members pivotally mounted thereon for movement between open positions and horizontally extended closed positions to confine a pipe in positions between said arms, a double acting fluid pressure operated actuator for each finger member, double acting valve means operable for respectively directing pressure fluid from a source to the respective actuators to operate the latter, spaced valve shifters associated with each of said valve means for operating the same, means for sequentially operating said valve shifters including a valve shifter operating member movable into successive operating relationship with said valve shifters, biasing means for moving said valve shifter operating member as aforesaid, and escapement means associated with said operating member, said escapement means including releasable means normally restraining movement of said operating member and releasable to allow movement of said operating member, and stop means associated with said operating member and operable for limiting movements of said operating member to increments of movement corresponding to the spacing of said valve shifters.

2. Apparatus as defined in claim 1, wherein said stop means includes a first stop element connected to said valve shifter operating member and movable with the latter, a second stop element actuatable into and from engagement with the firSt stop element, and means for actuating said second stop element.

4. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member including an elongated rod having stop elements spaced therealong, a second stop member having stop elements thereon, and means operable on said second stop member to shift the latter to effect engagement and release of said stop elements.

7. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, said first stop member having alternate notches and projections spaced thereon at opposite sides thereof, with a notch on one side opposite to a projection on the other side of said first stop member, a second stop member having opposed stop projections, said second stop member being actuatable to move the stop projections thereon alternately towards and away from opposite sides of said first stop member to alternately engage one stop projection of said second stop member in notches at opposite sides of said first stop member and to dispose the other stop projection on said second stop member for abutting engagement with a projection on said first stop member to position said one stop projection for engagement in a notch in said first stop member, and said biasing means adapted to move said valve shifter operating member and said first stop member relative to said second stop member when said stop projections on said second stop member are free of said notches.

8. Apparatus as defined in claim 1, wherein said stop means comprises a first stop member connected to said valve shifter operating member and movable with the latter, said first stop member having alternate notches and projections spaced thereon at opposite sides thereof, with a notch on one side opposite to a projection on the other side of said first stop member, a second stop member having opposed stop projections, said second stop member being actuatable to move the stop projections thereon alternately towards and away from opposite sides of said first stop member to alternately engage one stop projection of said second stop member in notches at opposite sides of said first stop member and to dispose the other stop projection on said second stop member for abutting engagement with a projection on said first stop member to position said one stop projection for engagement in a notch in said first stop member, and said biasing means adapted to move said valve shifter operating member and said first stop member in opposite directions relative to said second stop member when said stop projections on said second stop member are free of said notches.