US2807957A

US2807957A - Weight indicator and anchor for load sustaining lines

Info

Publication number: US2807957A
Application number: US170784A
Authority: US
Inventors: Elmer L Decker
Original assignee: Martin Decker Corp
Current assignee: Martin Decker Corp
Priority date: 1950-06-28
Filing date: 1950-06-28
Publication date: 1957-10-01
Anticipated expiration: 1974-10-01

Description

Oc. 1, 1957 E. l.. DECKER 2,807,957

WEIGHT INDICATOR AND ANCHOR FOR LOAD SUSTAINING LINES 2 Sheets-Sheet 1 Filed June 2S, 195o Arrow/Ey.

Oct l, 1957 E. L. DECKER 2,807,957

WEIGHT INDICATOR ND ANCHOR FOR LOAD SUSTAINING LINES Filed June 28, 1950 2 Sheets-Sheet 2 INVENTOR. 2,145@ ,pea-MEQ,

TT'oQ/VE Y.

nited States Patent C WEGHT INDICATR AND ANCHOR FOR LOAD SUSTAINING LINES Application June 28, 1950, Serial No. 170,784

13 Claims. (Cl. 73-143) This invention relates to apparatus for indicating the weight of loads on cables or other lines and for anchoring such lines, particularly the dead lines of cable hoist systems employed in the drilling of wells.

it is known that apparatus of this character as used in connection with rotary drilling rigs for oil wells comprises a footing on which a snubbing drum is mounted for limited turning movement and wherein a wire line clamp is mounted on an arm extended from the drum to anchor the dead line of the cable system which supports the drill string. A plurality of loops of this line are wound around the drum whereby the line is snubbed to relieve the clamp of the load on the line. When it is desired to feed fresh line into the system the clamp is released and the fresh line is extended into the system from a supply of cable disposed to one side of the clamp. A hydraulic sensing means is connected between the footing and the extended arm of the drum in such manner that responsive to limited turning movement of the drum, said element will operate a weight indicator to measure the load sustained by the lines of the system. While this apparatus is advantageous in that as a simple unit it serves the purposes of weight indication, deadending the line and feeding fresh line into the system, it is also objectionable due to the fact that the line must be reeved between the drum and its mounting in the operation of placing a number of windings around the drum, and as the line is quite stii, this operation is difficult and laborious, and the several complete windings often take a set that is difficult to straighten and in some cases damages or weakens the line.

It is therefore an object of this invention to provide an improved weight indicator and anchor of the character described.

It is another object of this invention to provide a weight indicator and anchor for a load sustaining line, which provide all of the advantages and none of the disadvantages of apparatus of this character as heretofore employed.

It is a further object of this invention to provide apparatus such as described which affords the desired snubbing action and anchoring of the line without requiring that several turns of the line be wound around a drum or wound in complete turns.

It is another object of this invention to provide an improved anchoring means for a load sustaining line in which the clamp for anchoring or dead-ending the line is relieved of objectionable stresses and wherein fresh line free from objectionable twists or bends may be fed through the anchoring means as desired.

It is another object of this invention to provide an apparatus such as described in which a lever instead of drum, having snubbing means thereon, provides for extending the line in a sinuous path in contact with the snubbing means to achieve the desired snubbing action without the 360 degree turns or windings heretofore required.

i t paratus such as described in which the line may be mounted sidewise in the apparatus in contact with the snubbing means without requiring any reeving of the line between parts of the apparatus or the winding of the line in complete turns, thereby avoiding the bending, kinking or twisting which tends to weaken the line or give it av set which is diicult of removal.

It is a further object to provide a weight indicator and line anchor unit such as described wherein the hydraulic sensing element may be adjusted to compensate for change in the number of load-sustaining lines employed.

It is another object of this invention to provide a weight indicator and line anchor wherein the sensing element may be adjusted or removed for inspection, reloading orrepair and replaced without requiring that the blocks be laid down and the drilling operation interrupted.

It is another object to provide apparatus such as described wherein the line is connected with a movable member by being convolved sinuously in one plane, thereby avoiding objectionable twisting of the line, and diffcult winding operations around a drum, as heretofore required, and making the movable member responsive to a straight line pull such that it will be accurately responsive to small increments of weight variation and provide for a greater nicety of weight measurement.

This invention possesses many other advantages an-d has other objects which may be made more easily apparent from a consideration of several embodiments of the invention. For this purpose there are shown two forms in the drawings accompanying and forming part of the present specication. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a diagrammatic view of apparatus embodying the present invention, as installed on the drill rig frame of a well;

'Figure 2 is an enlarged elevational view of the apparatus, with the safety plate removed, and the sensing device in section;

Figure 3 is a top plan view of the apparatus shown in Figure 2, with the safety plate mounted in place there- Figure 4 is a vertical sectional view taken on the line 4-4 of Figure 2;

Figure 5 is an enlarged fragmentary horizontal sectional view taken on the line 5-5 of Figure 2, showing the swiveled line orycable clamp;

Figure 6 is an enlarged sectional view taken online 6-6 of Figure 2, showing the line or cable clamp;

j Figure 7 is a sectional view taken on the line 7-7 of Figure 2;

IFigure 8 is a fragmentary front elevation of a modied form of this invention; and

Figure 9 is a sectional view taken on line 9-9 of Fig-ure 8.

As shown in Figure l, a weight indicating and line anchoring unit 9 embodying the present invention is mounted on the drill rig frame 10 of a well and has anchored thereto the dead line 11 Aof a `cable hoist -system as employed in connection with rotary drilling rigs, both of which latter are well known in this art and therefore not illustrated. The dead line 11 is joined to a supply of fresh cable 12 on a spool 13 supported adjacent the apparatus and from which fresh cable may be fed into the system through the apparatus. The apparatus includes a hydraulic sensing means 14 which responds to line loads imparted thereto, for operating a pressure operated weight gauge or indicator 15 of the type well known in this art, mounted in sight of the driller whereby the weight on the bit may be regulated according to the readings of the indicator in order that a more efficient drilling operation may be carried out.

More specifically, the apparatus comprises relatively movable members 16 and-17 on oneofkwhich is mounted a line clamp 1.8 for dead-endingthe deadline '11. Snubbing means 19 is mounted ontheother of said members for relieving the load on the clamp, relative movement between the members'operating the sensing means 14, which in turn operates thelindicator The member-16 comprises an elongated plate-like body 16a from one end of which` extends an integral arm 16h, the body being s ecurelyrfi'xedby bolts -20 to an upright member 10crof the drill Yrig frame 1D, whereby member 16 is stationarily .mounted with its opposite Hat faces substantially vertical. l Y

The member 17, being themovable member, cornprises an elongated .plate-likebody 17a pivoted to the member 16 intermediate'its ends so that it constitutes a lever. lt is mounted on anti-friction bearings 21 supported on a stub shaft 22fixedto the member 16a, as shown in Figure 4. An warm 17b as an integral extension of the body 17a ofthe member 17, is substantially equal in length to the arm 1;6b and disposed in vertically spaced relation thereto and substantially parallel therewith, the sensing means being connected to and disposed between saidarms.

As here shownthe cable or line clamp 18 is mounted on the end of the stationary member 16 opposite the end from which the arm 16b extends. It is swivelled on an extension 24 of the member 16 which projects beyond the adjacent end of the movable member` 17 and includes a base block 25 having' a -swivel pin 26 press tted or otherwise fixed thereto and mounted in a bearing 27 in the extension 24, `being held in place by `a suitable retainer ring 28. A clamping block 29 Ais adjustably and removably mounted on Vthe base block 25, by means of bolts 30. Opposed line embracing jaws 31 are mounted in complementary recesses 32 in the blocks and are forced into clamping engagement with the line upon tightening the bolts 30.

The snubbing means 19 mounted on the body 17a of the movable member `or lever 17 is such that the line or cable 11 is extended in a sinuous path, in one plane, and in snubbing contact therewith. This means is on the outer side of the member 17 and of such form that the cable may be positioned sidewise in contact therewith and does not require that the cable be wound therearound or thereon. Thus, this ,mean's as here shownv comprises a series of arcuate anges or like

elements

33, 34,35 and 36 which extend laterally outward from Vthe vertical surface of the member 17 in fixed relation thereto so as progressively in the order named, to describe a tortuous or sinuous path for the cablewithout requiring that any part of the cable in contact therewith form a complete 360 winding or be disposed out of onel vertical plane. Thus, from left to right as vseen in Figure 2, the cable passes over the upper side of the element 33, thence under and against element 34 and yaround and over the right end of the latter and back and around the arcuate element 35, which is concentric with the axis of the member 17, then around element 36 and up to the crown block (not shown) of-thehoist system. The lineal surfaces of these snubbing elements are of such extent and arrangement that in its contact therewith in asinuous path, the cable is not kinked or twisted or coiled in a manner comparable to that Where it is wound several times around a drum. lThe combined action of these elements is such that an effective snubbing takes place toY relieve the cable anchor 18 of strains and to make possible a limited movementgof the member 17 responsive to loads imposed` thereon-by the linexl'l. The cable contacting `surfaces of the elements Y33, 34, 35 and 36rare `grooved to retain the cablethereon. ...Howevenasafety 4 plate 37 is removably secured by means of fastenings 38 to the member 17 so as to overlie the snubbing element and cable thereon, thus assuring that the cable will be retained on said elements, as shown in Figure 3.

It should be noted `that the cable leads in a straight line from the clamp 18 in line with the axis of the movable member 17 until it encounters the first of the snubbing elements 33, which latter guides the cable below and forwardly of said axis thence upward and back toward the axis where the next element 35 carries the cable up and around the axis but not completely therearound. The cable then extends forwardly and above said axis in an arcuate path around the element 36 whence it leaves the upper end of element 36 in extending in a straight line to the crown block.

Responsive to the load pull on the line 11, the movable member 17 will rock on its axis so that the arm 17b will be raised relativeto the arm 16b while the other end VVof the member 17 lwill be lowered. In this connection itshould Vbe noted that the pivotal mounting of the cable clamp 18 permits the clamp to turn to prevent sharp bending ofthe cable adjacent the clamp when the member 17 is rocked relative Vto the clamp as above noted. However, this relative movement between the members 16 and 1-7 is comparatively small, being so limited by the sensing element 14.

Means are provided, as best shown in Figures 2 and 7, for additionally limiting relative movement between the arms 16 and 17particularly so that the sensing element may be adjusted or removed and replaced without lowering the blocks and interrupting the drilling operation. This means includes a link 39 straddling the

arms

16b and 17b, with its other` end closed below the arm 16b by suitable means, for example, a spacer block 41 held in place lby bolts 42. A screw 43 is adjustable in the block 41 and normally spaced below the arm 16b sutlciently to permit of relative movement between the arms 17b and v16b for proper operation of the sensing element 14, such relative movement being preferably limited by the sensing element rather than link 39. However, this screw may be adjusted so that it will contact arm 1Gb and prevent movement between

arms

16b and 17b whereby the sensing element 14 may be adjusted, removed and replaced without requiring that the load be taken off the dead line 11, or the drilling operation interrupted. Furthermore, if the seusing element 14 is removed without adjusting the screw from its normal position, the screw will contact arm 16h with `but a small upward movement of the arm 17b as caused by the load on the line 11, since the normal spacing of the screw from the arm 1Gb is very slight due to the sensing element being fully operable with a small movement of the arm 17b. However, in most cases it is desirable to relieve the load on the sensing element for adjusting, removing, and replacing it, thus this screw and its associated parts serve as a means by which the arm 17 may be lowered, that is swung downward, .while the dead line load is carried thereby, and so held to relieve the load on the sensing element to facilitate adjustment, removal and replacement of the sensing element, as will be hereinafter more fully described.

The

arms

16b and 17b are comparatively long and the armf16b is offset at 16c as shown in Figure 3 so as to vertically align wit-h arm 17b and to accommodate proper installation of -the y.sensing element 14 between said arms.

As shown in Figure 2, the sensing element 14 comprises a hydraulic cylinder 44 and a piston 45, the

cylinder being connected with the stationary arm 1Gb by means of a link 46 while the piston rod 47 or piston 45 is connected by means of a similar link 48 with the mov- Aable arm-17b. A hydraulic line49 leads from the top of the cylinder 44 to the hydraulically operated indicator 15. This line `with the cylinder 44 and indicator 1S forms a closed hydraulic system whereinthe cylinder and piston are initially installed between the

arms

16b and 17b in such manner as topermt of limited movement of arm 17b according to the setting of the stop link 39 and the stroke of the piston 4S for example, as indicated lin Figure 2. Thus, as the movable arm 17b is raised relative to the stationary arm 16b responsive to the pull of the cable on the movable member 17 and consequent rocking of the latter on its axis, the piston 45 is lifted relative to the cylinder 44 and fluid displaced from cylinder 44 becomes etfective in the indicator 15 to measure the load on the line 11.

The

arms

16b and 17b with the

links

46 and 48 provide a means for adjusting the sensing element longitudinally of the arms, there being

companion notches

50 and 51 at longitudinally spaced points in th-

e arms

16b and 17b respectively for accommodating removable pins or bolts 52 and 53 in the respective links, to hold the sensing means in adjusted positions. This adjustment is effected in accordance with the number of lines operating from the travelling block in the hoisting system, the sensing element being moved toward the outer ends of the arms with a reduction of the number of lines and inwardly from said outer ends with an increase of lines.

It is important to note that the sensing element may be adjusted, or removed for reloading, inspection or repair and replaced without lowering the blocks or interrupting the drilling operation, the dead line load being maintained on the movable members 17 all the while. The screw 43 when turned by means of a suitable tool, not shown, so as to contact the arm 16b and move the arm 17b toward arm 16b makes it possible to adjust the sensing element as desired along the arms 17b and 1611 or to remove and replace the sensing element Without interrupting the drilling operation. The screw may be readily retracted to normal position shown in Figures 2 and 7, after the sensing element is adjusted or replaced, thereby restoring the appartus for weight indicating operation.

It should be noted that in accordance with this invention the line 11 is sinuously. convolved in one vertical plane. In other words, the line, in contacting the reversely curved snubbing

elements

33, 34, 3S and 36, is formed into a series of reversely curved loops, with opposite sides of the portion of the line forming the loops, frictionally engaged by the snubbing elements. This makes it unnecessary to twist or kink the line and provides for an easy application thereof to the snubbing elements on the movable member 17. This arrangement also provides for a straight line pull on the movable members and an accurate response to small increments of load variation, thus affording a nicety of weight indication. Moreover, in making the snubbing convolutions of the line in one plane, the bulk of the apparatus is reduced and the construction thereof simpliiied compared to the drum-type apparatus heretofore provided.

The apparatus hereof without the indicating means will serve as an eicient cable anchor with provisions for relieving the cable clamp from objectionable stresses and for feeding into the system as desired fresh cable which is free from objectionable twists or bends.

As shown in Figures 8 and 9, a modified form of this invention provides for mounting a releasable line or cable clamp S on the movable member 17 instead of on the stationary member 16. This clamp is similar to the clamp 18 but is xed to an extension 56 on the movable member 17 instead of being pivoted, inasmuch as movement of the clamp with the member 17 precludes the necessity of pivotally mounting it. With the exception of providing the extension 56 on the member 17 instead of on the member 16, and fixing the clamp to extension 56, this modified form of the invention is of the same construction and arrangement as the form of the invention shown in Figures l and 6 inclusive.

I claim:

l. In a weight indicator and anchor for a load sustaining line, the combination of; a stationary member, a member mounted thereon for pivotal movement with respect thereto, means on said pivoted member forming reversely curved surfaces for contact with said line throughout a sinuous path, a clamp for dead-ending said line on said stationary member, and relative motion resisting weight indicating means interconnected between said members for operation responsive to relative movement thereof.

2. In a weight indicator and anchor for a load-sustaining line, the combination of; a stationary member, a member mounted thereon for pivotal movement with respect thereto, means on said pivoted member forming reversely curved surfaces forv contact with said line throughout a sinuous path, a clamp pivoted on said stationary member, operable for releasably anchoring the line and to turn on its pivot responsive to pivotal movement of said pivoted member, and relative motion resisting weight indicating means interconnected between said members and operating responsive to relative movement between said members.

3. A weight indicator and anchor for a load sustaining line comprising in combination: a stationary member, a relatively movable member, means on one of said members for contacting and snubbing the line throughout a sinuous path to cause relative movement of the members responsive to pull on the line, means for releasably clamping said line, means mounting said clamping means on one of said members for movement relative thereto re- .sponsive to relative movement between said members, and relative motion resisting weight indicating means interconnected between said members responsive to relative movement of said members.

4. In a weight indicator and anchor for a load-sustaining line, the combination of; a stationary member, a

-movable member pivoted on the stationary member With a surface thereof vertically disposed, a plurality of arcuate elements extending laterally outward from said surface and forming surfaces in a sinuous path for contacting opposite sides of the line and snubbing theV line, means for releasably anchoring the cable to one of said members and means for attaching a relative motion resisting weight indicator between said members for operation responsive to relative pivotal movement of said movable member With respect to said stationary member.

5. In a Weight indicator and anchor for a loadsustaining line, the combination of; a stationary member, a movable member pivoted on the stationary member with a surface thereof vertically disposed, a plurality of arcuate elements extending laterally outward from said surface and forming surfaces in a sinuous path for contacting opposite sides of the line and snubbing the line, means for releasably anchoring the cable to one of said members, means for attaching a relative motion resisting weight indicator between said members for operation responsive to relative pivotal movement of said movable member with respect to said stationary member, and means mounted on said movable member and overlying said arcuate elements to retain the line in contact therewith along said path.

`6. A weight indicator and anchor for a load sustaining line comprising in combination: a stationary member, a relatively movable member, means for anchoring the line to one of said members; means on one of said members forwardly of said anchoring means for contacting opposite sides of the line and snubbing the line and causing relative movement between said members responsive to the pull on said line, relative motion resisting means interconnected between said members operating in response to relative movement thereof to indicate the pull on said line, and means interconnected between said members operative at will to effect relative movement between said members.

7. A weight indicator and anchor for a load sustaining line comprising in combination: a stationary member, a relatively movable member, means for anchoring the line to one of said members; means forwardly of said anchor- 27 ing means on one of said members forming reversely curved surfaces for contacting opposite Vsides of the line and snubbing the line and causing relative movement between said members responsive to the pull on said line, relative motion resisting means interconnected between said members operating in response to relative movement thereof to indicate the pull on said line, and means interconnected between' said members operative at will to leiiect relative movement between said members in` a direction opposite that caused by the pull on the line.

8. In a weight indicator and anchor for a load-sustaining line; the combination of a stationary member including an axis; a movable member mounted for relative movement about said axis; an arm carried by each of said members extending outwardly from said axis; means for anchoring the line to one of said members; means on one of said members against which the line is engageable in the form of a plurality of reversely curved loops for etecting a snubbing action on the line and relative movement between said members responsive to the pull on the line; and relative motion resisting weight indicating means connected between said arms for operation responsive to relative movement of said members.

9. In a weight indicator and anchor for a loadsustaining line; the combination of a stationary member including an axis; a movable member mounted for relative movement about said axis; an arm carried by each of said members extending outwardly from said axis; means on one of said members for anchoring the line thereto; reversely curved elements on one of said members against which opposite sidesof the line are engageable to effect a snubbing action on the line and relative movement between said members responsive to the pull on the line; relative motion resisting weight indicating.

means connected between said arms for operation responsive to relative movement of said members; and means affording the connection of said indicating means to said arms at points variously spaced from said axis.

10. In a weight indicator and anchor for a loadsustaining line; the combination of a stationary member including an axis; a movable member mounted for relative movement about said axis; an arm carried by each of said members extending outwardly from said axis; means for anchoring the lineto one of said members; means on one of said-members against which the line is engageable to effect a snubbing `action on the line and relative movement between said members responsiveto the pull on the line; relatvemotion resisting vweight indicating means connected between said armsfor operation responsive to relative movement of said members; ajlink pivoted to one of said arms; and a memberf on said link adapted to engagethe other of said arms tolimit relative movement between said arms.

11. ln a weight indicator `and anchor for a load-sustaining line; the combination of a stationary member including an axis; a movable member mounted for relative movement about said axis; an arm carried by each of said members extending outwardly from said axis; meansr on one of `said jmembers for anchoring the line thereto; means on one of said members against which the lineiseugageable to effect a snubbing action on the line and relative 'movement between said members responsive to Athe pull on the line; relative motion resisting weight indicating means connected between said arms for operation vresponsive to relativemovement of said members; a link pivoted to one of said arms; and an adjustable member on said link operable against the other of said arms for effecting relative movement be tween said arms in a direction opposite that caused by the line pull.

l2.In a weight indicator and anchor for a load-sus taining line; the combination of a stationary member including an axis; a movable member mounted for relt tive movement about said axis; an arm carried by cach of said members' extending outwardly from said axis; means on one of said members for anchoring the line thereto; elements on one of said members variously spaced from said axis and against which the line is engageable to effect a snubbing action on the line and rela tive movement between said members responsive to the pull on the line; relative motion resisting weight indicating means connected between said arms for operation responsive to relative movement yof said members; `means affording the connectionof said indicating means to said arms at points variously spaced from said axis; and means connected with said arms including a member adjustable for etfectingrelative movement between said arms in a direction opposite that caused by the line pull,

13. In a weight indicator and lanchor for a tainingline; the combination of a stationary member; a ,movable member pivoted on the stationary member; said movable 1 member having a surface substantially perpendicular to the pivotal axis thereof; a plurality of arcuate elements extending outwardly from said surface and providing snubbing surfaces in a sinuous path for contacting opposite sides `of the line; means releasably anchoring Vthe `line to one of said members; and means providing for the attachment of a relative motion resisting weight indicator between said members for operation responsive to pivotal movement of said movable member with respect to said stationary member.

References Cited in the le of this patent UNITED STATES PATENTS 1,247,249 Felcyn Nov. 20, 1917 1,692,057 Smith Nov. 20, 1928 1,793,330 Magnant Feb. 17, 1931 1,984,241 Sumenius Dec. 11, 1934 2,013,938 Williams Sept. 10, 1935 2,025,928 Wunsch Dec. 31, 1935 2,277,925 MacClatchie Mar. 31, 1942 2,488,070 Spalding Nov. l5, 1949