US2557543A - Safety device for drilling derricks - Google Patents

Description

June 19; 1951 G. E. KEMNITZ 2,557,543

SAFETY DEVICE FOR DRILLING DERRICKS Filed March 10, 1950 2 Sheets-Sheet 1 INVENTOR. GEORGE E. KEMNITZ BYK WN /W ATTORNEYS G. E. KEMNITZ SAFETY DEVICE FOR June 19, 1951 DRILLING DERRICKS 2 Sheets-Shet 2 Filed March 10, 1950 INVENTOR.

Patented June 19, 1951 SAFETY DEVICE FOR DRILLING DERRICKS George E. Kemnitz, Tulsa, Okla., assignor to Noble Drilling Corp., Tulsa, Okla., a corporation of Delaware Applic'ation March 10, 1950, Serial N 0. 148,906

11 Claims.

The present invention relates to drilling derricks or masts, and more particularly to safety means capable of attachment to the legs of conventional drilling derricks or masts to prevent Fig. '7 is a broken section taken along line l--1 of Fig. 5 and also viewed in the direction of the arrows.

Referring to the drawing, the drilling derrick injury to members of a drilling crewby a joint of 5 or mast I0. is positioned above the rotary table I I drill pipe or casing falling while it is bein hoisted located at the center of the derrick floor l2. At above the derrick floor from the pipe rack. one side of the derrick floor [2 is the conventional In oil well drilling or similar'drilling operations, draw works [3 from which the drilling line M the derrick is positioned above the rotary table runs up through the crown block (not shown) located at the center of the floor and pipe lengths 19' and to traveling blocks (not shown) supporting are hoisted above the level of the fioor through the hook (not shown) and elevators. At one end a door frame in the derrick or tower from a of the draw works is a winch or cathead I5. 0p rack outside the derrick and below the level of the: posite the draw works on the opposite side of the derrick floor, being pulled up a ramp during derrick or tower I0 is the entrance frame or V- hoisting. Frequently during hoisting the hoisting door It through which additional drill pipe or cable will break while the pipe lengths are suscasing lengths ll are brought and hoisted above pended therefrom and permit them to fall onto the floor 12 as needed. The pipe or casing lengths the floor and injure or kill members of the drill I? are usually racked outside the derrick on a crew on the floor. Principal objects and features lower level than the derrick floor l2 and are of this invention are the provision of simple safepulled up a ramp or walkway is by attaching a ty means or safeguards designed to prevent-such sling line lg to the Section length H to injuries or death by trapping the pipe lengths in moved from the rack to a position above the-floor their fall on breakage of the hoisting line and I2; The sling line i9 is run through the crown precluding their falling to the floor of the derblock (not shown) and the other end is wound rick. around the winch or cathead l5 which is moti- Further principal objects and features of the vated'by the draw worksl3. Sometimes the sling invention are the provision of. safety means of e 9 W b as e p pe length I7 s being the character described that are simple in conhoisted above the derrick floor l2 as described struction, relatively inexpensive and capable of and the pipe length will fall or drop to, the derbeing installed on existing structureswithout any ric floor W ere t may Strike d S e y material modification of the latter. lure-or kill a member 01 the drilling crew.

Other objects and novel features will become e'safety means e y th ve tion has apparent from the following specification and as its P p l bje t t Provision Of a r ppin accompanying drawings, wherein similar refer ar a eme t at Will absolutely p a y ence characters denote corresponding parts and 5 i ju y t drill OreW in the event of b a wherein: of a sling line during the hoisting operations Fig. l is a vertical elevation, partially in sec-- just described. To this end, one bracket 29 of a tion of a conventional drilling. derrick equipped. p of brackets av ng a hooked-flange 283a is sewiththe safety means of the invention; Cured y a Clamp plate la d bolts 22 a d uts- Fig. 2 is a transverse section taken along line 23 to one of the frame legs 25 of the frame or 2-2 of Fig, 1 and viewed inthe dir tio of the V-door I6 adjacent its lower end; A similar arrows; bracket 28 is similarly secured to the other frame Fig. 3 is an elevational' view of the derrick of. leg' 25 of the frame or'V-door i6: Each bracket Fig; l viewed from the right of Fig. I and: show- 0- has' a pivot Shaft 25 fixed to and extending: ing one position of the drill pipe being. hoisted; a rally r f a d utwa d y of th v-doon above the derrick floor; A lever arm 21. is rotatively supported oneach Fig. 4 is a similar elevational view showing arrshaft 26 being. located and held in place rotative-r other position of the drill pipe being hoisted and 1y thereon by washers 2'8, 29" and a cotter pin 30. I in relationship to the safety means; Each leverZ-l fits telescopically in one end of a Fig. 5 is an enlarged fragmentary elevation tubulararm 3i. The latter is secured to the illustrating detailsof construction of the safety lever on which it fits by a Collar 32 and cross'boltmeans; 33. The two arms 3| are oppositely directed.

Fig. 6 is a transverse section taken along line toward each other and their adjacent outer ends 6-6 of Fig; 5 and viewed in thedirectionof the 3M. are preferably closed by plugs 34 whose arrowsyand meeting outer surfaces are angularly shaped in,

complementary manner so that the two angular surfaces of the plugs meet and permit the two adjacent ends of arms 3| to form a substantially closed inverted V in their lowermost positions. A cable securing sleeve 35 carrying a cable securing loop 36 is mounted on each pipe 3|. A cable coupler 31 is secured to each loop 36 and a cable of wire-or rope 38 in turn has one end secured to each coupler 31. The other ends of cables 38 are each secured to a coupler 39 and each latter coupler is secured to a fixed ring 40, each ring 4|), in turn, being fixedly mounted to one of the frame legs 25 of the frame or V-door 6 above the clamp plate 2| on that leg. The two cables 38 serve to limit downward rotation of the two arms 3| to their lowermost positions shown in Figs. 3, 4 and 5, wherein their ends meet without, however, interfering with upward rotation of the two arms on their pivot shafts 26.

These two arms 3| supported as described in the frame or V-door l5 and their cables 38 provide a very effective safety means for drill crew members on the floor I2 of the derrick. As the winch I5 is operated to draw sling line H! in a hoisting direction of a pipe length H, the latter is drawn up the ramp I8 and through the frame or V- door I 6. In the hoisting travel of the pipe length |l, its surface engages the undersides of arms 3| adjacent the outer ends 3|a and pivots each arm about its shaft 26 to permit separation of the ends 3|a sufiiciently for the pipe length I! to pass between the separated ends to the upper side of pipes 3| whereupon the latterimmediately fall by gravity to their cable limited lowermost positions, closing the gap between adjacent ends 3|a of the arms. This occurs early in the hoisting operation. Any subsequent breaking of the sling line during hoisting of the pipe length N, since the latter is at an angle to the vertical, simply allows the pipe length to fall onto the top sides of the arms 3| or cables 38. These arms 3| or cables 38 thus form a trap, blocking a fall of the pipe length N onto the floor of derrick l2 because of their described return to meeting position immediately after pipe is drawn through the gap between the arms and thereby protect the drilling'crew below on the derrick floor l2 against injury or death.

The arrangement while very simple in practice has proved very effective in the field as a crew safety device. Its ready installation on existing structures adds greatly to its commercial utility and, when installed, reduces one of the causes of large accident rates in drilling operations.

While a specific embodiment of the invention has been described and shown, variations in structural detail within the scope of the claims is possible and is contemplated. There is no intention, therefore, of limitation to the exact details shown and described.

What is claimed is:

1. In a drilling derrick having an entrance frame and means for hoisting a pipe length through the frame and above the floor of the derrick, safety means comprising a pair of oppositely directed arms each pivotally supported at one of its ends at opposite sides of the frame and normally having their free ends meeting, means for preventing pivotal movement downwardly of the two arms substantially below the meeting position of their free ends while permitting upward pivotal movement of the arms to provide temporary separation of the free ends thereof during passage in upward direction therebetween of a pipe length being hoisted, said arms being free to return under the influence of gravity to meeting relationship of their said free ends thereby providing a trap above the derrick floor to prevent the length of pipe being hoisted from falling onto the floor.

2. In hoisting apparatus for lifting pipe lengths through an entrance frame and over a floor, safety means comprising a pair of oppositely directed arms each pivotally supported at one of its ends at opposite sides of the frame and normally having their free ends meeting, means for preventing pivotal movement downwardly of the two arms substantially below the meeting position of their free' ends while permitting upward pivotal movement of the arms to provide temporary separation of the free ends thereof during passage in upwarddirection therebetween of a pipe length being hoisted, said arms being free to return under the influence of gravity to meeting relationship of their said free ends thereby providing a trap above the derrick floor to prevent the length of pipe being hoisted from falling onto the floor.

3. The safety means of claim 2, wherein brackets are secured to the frame, each bracket having a pivot stud, and wherein levers are rotatively mounted one on each pivot stud and wherein the arms fit telescopically one on each lever and are secured thereto.

4. The safety means of claim 2, wherein brackets and clamp plates for securing the brackets to the frame are provided, a pivot stud on each bracket and levers rotatively mounted one on each pivot stud, wherein the arms are tubular and fit telescopically one on each lever and wherein means for securing each arm to the lever on which it fits are provided.

5. The safety means of claim 2, wherein the means for limiting downward pivotal movement of the two arms includes a cable of determined length connected to each arm and to the frame.

6. Safety means for application to the frame of a drilling derrick, wherein pipe lengths are hoisted through the frame and above the derrick floor comprising a pair of oppositely directed arms each pivotally supported at one of its ends at opposite sides of the frame above the floor and normally having their free ends meeting, means for preventing pivotal movement downwardly of the two arms substantially below the meeting position of their free ends while permitting upward pivotal movement of the arms to provide temporary separation of the free ends thereof during passage upwardly therebetween of a pipe length being hoisted, said arms being free to return under the influence of gravity to meeting relationship of their free ends, thereby providing a trap above the floor to catch and prevent the pipe length being hoisted from falling onto the floor.

7. The safety means of claim 6, wherein the arms in the meeting position of their free ends define a closed substantially inverted V.

8. The safety means of claim 6, wherein the means for limiting downward pivotal movement of the two arms comprise cables secured both to the arms and to the frame.

9. The safety means of claim 6, wherein each arm is tubular and fits telescopically on a lever and is secured thereto, brackets secured to the frame, and pivot studs secured to the brackets, each lever being pivotally mounted on one of the pivot studs.

10. The safety means of claim 6, wherein each arm is tubular and flts telescopically on a lever and is secured thereto, brackets secured to the frame, and pivot studs secured to the brackets,

each lever being pivotally mounted on one of the pivot studs and wherein the means for limiting downward pivotal movement of the two arms comprise cables secured both to the arms and to the frame, and wherein the arms in the meeting position of their adjacent ends define a closed substantially inverted V.

11. In combination with a drilling derrick having a V-door structure and means for hoistinga pipe length through the door and over the floor of the derrick, safety means comprising a pair of oppositely directed arms, means for pivotally supporting one end of each arm from one of the opposite sides of the structure forming the V- door, and means for preventing pivotal movement in a downward direction of at least one of said arms below that position at which the free REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,049,008 Herrick July 28, 1936 2,184,051 Moise Dec. 19, 1939

Images