US2889898A

US2889898A - Combination oil well derrick and tilting construction boom

Info

Publication number: US2889898A
Application number: US665565A
Authority: US
Inventors: Homer J Woolslayer; Charles D Iddings
Original assignee: Lee C Moore Corp
Current assignee: Lee C Moore Corp
Priority date: 1957-06-13
Filing date: 1957-06-13
Publication date: 1959-06-09
Anticipated expiration: 1976-06-09

Description

June 1959 H. J. WOOLSLAYER ET AL 2,889,898

COMBINATION on. WELL DERRICK AND TILTING CONSTRUCTION BOOM Filed June 13,1957

2 Sheets-Sheet 1 m w mam 6 3 2 WWW. m H h m M mm I. j Ww P r kwfiyw m United States Patent Ofifice 2,889,898 Patented June 9, 1959 COMBINATION OIL WELL DERRICK AND TILT IN G CDNSTRUCTION BOOM Homer J. Woolslayer, Cecil Jenkins, and Charles D.

Iddings, Tulsa, Okla, assignors to Lee C. Moore Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application June 13, 1957, Serial No. 665,565

Claims. (Cl. 189-15) This invention relates to oil well derricks, and more particularly to those in which a tilting mast is formed from a pair of spaced upright columns connected by a. truss.

In certain cases, especially in off-shore drilling, it would be desirable to be able to use the drilling mast as a construction boom before drilling is started. A wellknown type of drilling mast lends itself to such a combination of functions because the mast is hinged to a base so that the mast can be swung up to upright position from a reclining position in front of the base. By providing means for tilting the mast backward from its upright position to any desired angle, the mast could serve as a construction boom except that the bracing across the back of the mast would interfere with the movements of the traveling block used as a construction hoist.

It is among the objects of this invention to provide an oil well derrick which can be used both for drilling and for construction work, which is adequately braced for both operations, which includes bracing that can be shifted from one position to another depending on whether the mast is being used for drilling or as a tilting boom, and in which the shiftable bracing can be handled easily and quickly.

In accordance with this invention, a pair of laterally spaced upright columns that are rigidly connected at their upper ends have their lower ends hinged to a base. The columns normally are held upright to form a drilling mast. At such times, a truss located between the columns has its opposite ends detachably connected to the backs of the columns to brace the back of the mast. The front of the mast is left open to permit pipe to be racked beside the mast. Means are provided for tilting the mast backward from its upright position so that it can be used as a construction boom with the traveling block hanging straight down from the upper end of the tilted boom. To prevent the truss from interfering with the traveling block, suspension members extend forward from the ends of the truss and are pivotally connected to means supported by the inner sides of the columns midway between their fronts and backs. Therefore, when the truss is disconnected from the backs of the columns, it can be swung down and forward and then up to a position between the fronts of the columns, where the truss can be connected to the columns again to brace the front of the mast. Consequently, the mast is braced whether it is used for drilling or as a construction boom, but the bracing does not interfere with either operation- The preferred embodiment of the invention is illustrated in the accompanying drawings, in which: v 7

Fig. 1 is a side view of our derrick showing the'mast in drilling position, but indicating in dotted lines its use as a constructon boom;

Fig. 2 is a fragmentary rear view of the mast;

Fig. 3 is an enlarged fragmentary rear view of the mast showing the truss connected to the backs of the columns;

Fig. 4 is a horizontal section through the mast immediately above members 31 of Fig. 3; and

Fig. 5 is a vertical section taken on the line VV of Fig. 3.

Referring to Figs. 1 and 2 of the drawings, an oil well derrick mast is formed from a pair of upright structural steel columns, each of which is constructed from a pair of front legs 1 rigidly connected to a pair of back legs 2 by suitable braces 3. The lower ends of the columns are spaced a considerable distance apart and their upper ends are spaced apart a somewhat lesser distance. The upper ends are rigidly connected by a framework 4 that supports the usual crown block 5, from which a traveling block 6 is suspended between the columns by lines 7 connected with a draw-works 8 on a suitable base 9. The lower ends of the columns are hinged to the base, and the mast is held upright by a gin pole 16 mounted on the base behind it.

For at least the major portion of its height the front of the mast is free of cross braces between its columns, but the usual racking platform 12 projects from the fronts of the columns at a predetermined height above the base. The capacity of the mast is increased materially by bracing the columns by means of a truss 13 spanning the space between them above the gin pole. The mast can be lowered into reclining position in front of the base by means of the traveling block and a sling line (not shown) in a well-known manner. The mast is also raised from reclining to upright position by the traveling block pulling on the sling line. It will be seen that the mast, as described thus far, is used in conventional manner for drilling oil wells.

There are times when it is desirable to also use this mast as a construction boom, such as when the mast is intended for offshore drilling. In that case, the base may be mounted on one end of a barge 14 or on a platform supported above the water by piling. The mast can be used as a boom by connecting suitable block and tackle 15 to the upper end of the mast and to a lufling hoist 16 a considerable distance in front of the mast. Tension is put on the tackle by means of the hoist to hold the mast while the rear legs of the gin pole are disconnected from the base and swung backward over the rear edge of the base or allowed to extend down through openings in it. The hoist is then operated to allow gravity to tilt the mast over backward so that its upper end will be located behind the base and underlying structure, as shown in dotted lines in Fig. 1. This will cause the traveling block to swing out of the back of the mast above truss 13 and hang straight down from the crown block behind the mast. It will be seen, however, that when the mast is pulled back toward upright position with a load hanging from the traveling block, the truss at the back of the mast may interfere with the load or the block.

It is therefore a feature of this invention that the truss can be moved into another position where it will still brace the mast but will not interfere with its use as a construction boom. For this purpose, as shown in Fig. 3, the truss is constructed from the heavy top and bottom horizontal members 20, such as I-beams, rigidly connected by vertical and inclined braces 21. The top and bottom members or chords of the truss are the same length, so that the truss is rectangular to enable it to fit either side up between the columns. The opposite ends of the chords are connected by bolts 22 to the adjoining ends of short

horizontal braces

23 and 24 welded across the back of each column. These braces preferably are the same size and shape as the chords of the truss, except they are shorter. The lower braces are longer than the upper ones to compensate for the inclination of the columns. The truss is slightly shorter than the distance between the columns at truss level. It will be seen that this construction provides heavy bracing across the back of the mast, which stiifens it and thereby increases its working capacity.

Projecting forward from the opposite ends of the truss are suspension members. Preferably, these members consists of rigid bars 26 welded to the ends of chords 28. As shown in Fig. 5, the upper bars are inclined downward toward the center of the mast and the lower bars are inclined upward. The pair of converging bars at each end of the truss have their inner ends rigidly connected together and to a trunnion 27 that projects out into a bearing 28 mounted on the cross bracing 3 of the adjoining column midway between its front and back. Consequently, if the truss is disconnected from the backs of the columns, the bearings will permit it to swing down between the columns, where it will be supported by the trunnions.

When it is desired to do this, the traveling block is connected with the top of the truss to support it while it is disconnected from

braces

23 and 24 and then the block is lowered to allow the truss to swing down and forward into horizontal position between the columns. The traveling block then is disconnected from the truss and connected with its opposite side, following which the block is raised in the mast to swing the truss forward and up between the front sides of the columns. Upward movement of the truss is limited by stops 29 that project from the inner ends of horizontal braces 30 welded to the front legs of the columns like the corresponding braces 23 at the back of the mast, which support similar stops 3.1. The ends of the truss can be bolted to front braces 30 and lower braces 32 to brace the front of the mast. With the truss at the front of the mast, the mast can now be used as a boom without interference from the truss, and yet the benefit of the truss will continue to be obtained. To convert from a boom to a drilling mast, the mast is pulled upright, the back legs of the gin pole anchored to the bars, and the truss returned to the back of the columns.

If it were not for the pivotal support of the truss at bearings 28 in the mast while the truss is disconnected from the columns, it would be extremely difficult to handle the truss and guide it into correct position. The pivotal connection restricts the movement of the truss to a predetermined arc and therefore controls its move ment from one side of the mast to the other. This guiding or control also assures alignment of the bolt holes of the truss chords and the adjoining column braces, so that the truss can be quickly and easily bolted to either the front or the back of the mast. No manual guiding of the truss into place is required, as it is controlled entirely by lowering and raising the traveling block.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. A combination oil Well derrick and tilting construction boom, comprising a base, a pair of laterally spaced upright columns rigidly connected at their upper ends, means hinging the lower ends of the columns to the base, means normally holding the columns upright to form a drilling mast adapted to support its working loads along a vertical line between the columns, a truss located between the columns, means detachably connecting the opposite ends of the truss to the backs of the columns to brace the back of the mast, means connected to the mast to tilt it backward as a construction boom, suspension members extending forward from the ends of the truss, and axially aligned means supported by the inner sides of the columns midway between their fronts and backs and pivotally connecting said members to the columns on a single common axis to permit the truss to be swung down and forward bodily and then up to a bottom side up position between the fronts of the columns, the truss being connectable to the columns when it is in said forward position to brace the front of the mast while it is used as a boom.

2. In an oil well drilling mast mounted for tilting backward from a substantially vertical drilling position to an inclined hoisting position, the combination with a pair of laterally spaced upright columns rigidly connected at their upper ends, of a truss located between the columns, means detachably connecting the opposite ends of the truss to the backs of the columns to brace the back of the mast, suspension members extending forward from the ends of the truss, and axially aligned means supported by the inner sides of the columns midway between their fronts and backs and pivotally connecting said members to the columns on a single common axis to permit the truss to be swung down and forward bodily and then up to a bottom side up position between the fronts of the columns, the truss being connectable to the columns when it is in said forward position to brace the front of the mast.

3. The combination recited in claim 2, in which the truss has parallel upper and lower longitudinal members connected by braces, and the fronts and backs of the columns are provided with pairs of parallel horizontal members that form continuations of said longitudinal members when the truss is connected to them,

4. In an oil well drilling mast mounted for tilting backward from a substantially vertical drilling position to an inclined hoisting position, the combination with a pair of laterally spaced upright columns rigidly connected at their upper ends, of a truss located between the columns, means detachably connecting the opposite ends of the truss to the backs of the columns to brace the back of the mast, rigid suspension members projecting forward from the ends of the truss, a pair of axially aligned bearings supported by the inner sides of the columns midway between their fronts and backs, and trunnions mounted in the bearings and secured to the front ends of said suspension members to permit the truss to be swung down and forward bodily and then up to a bottom side up position between the fronts of the columns, the truss being connectable to the columns when it is in said forward position to brace the front of the mast.

5. The combination recited in claim 4, in which a pair of said suspension members at each end of the truss converge toward the trunnion ahead of them.

References Cited in the file of this patent UNITED STATES PATENTS 2,168,837 York Aug. 8, 1939 2,345,253 Funk Mar. 28, 1944 2,780,326 Woolslayer Feb. 5, 1957 2,781,108 Selberg et a1. Feb. 12, 1957 OTHER REFERENCES World Oil Publication, May 1957, p. 137.