US3295270A

US3295270A - Folded oil well mast structure

Info

Publication number: US3295270A
Application number: US409089A
Authority: US
Inventors: Homer J Woolslayer; Jenkins Cecil
Original assignee: Lee C Moore Corp
Current assignee: Lee C Moore Corp
Priority date: 1964-11-05
Filing date: 1964-11-05
Publication date: 1967-01-03
Anticipated expiration: 1984-01-03
Also published as: NL6510594A; GB1058072A

Description

Jan. 3, 1967 H. J. WOOLSLAYER ETAL 3,295,270

FOLDED OIL WELL MAST STRUCTURE 5 Sheets-Sheet 1 Filed Nov. 5, 1964 //VVE/V7'0R5. HOMER J. WOOLSLAYER CECIL Jf/Vkl/V-S ATTORNEYS.

3, 1967 H. J WOOLSLAYER ETAL 3,295,270

- FOLDED OIL WELL MAST STRUCTURE 5 Sheets-$heet 2 Filed Nov. 5, 1964 IIAL u M T M Arrow/5V5.

Jan. 3, 1967 H- J. WOOLSLAYER ETAL FOLDED OIL WELL MAST STRUCTURE Filed Nov. 5, 1964 5 Sheets-Sheet :5

wumro/Qs i) HOMER J. WOOLSLAYER cam JEAN/NS mgwawwm ATTOR ilnitd rates atent 3,295,270 FOLDED 01L WELL MAST STRUCTURE Homer .l. Woolslayer and Cecil Jenkins, Tulsa, Dltla, assignors to Lee C. Moore Corporation, Pittsburgh, Pa, a corporation of Pennsylvania Filed Nov. 5, 1964, Ser. No. 469,039 11 Claims. (Eli. 52-417) This invention relates to oil well masts that can be folded for transportation from one location to another.

Oil well drilling masts that can be swung upward from the ground to upright drilling position are well known, but generally such masts have to be controlled in their movement by a snub line connected with a winch truck. When it is desired to carry such a mast on a barge, the limited space on the barge deck precludes the use of a winch truck or the like. Folding masts, which can be raised and lowered in a limited area without a snub line, also are known, but in the past they have been rather complicated in construction and operation. Nevertheless, a folding mast is desirable for a barge so that the mast can be lowered, without being dismantled, while the barge is under tow from one location to another.

It is among the objects of this invention to provide a folded mast structure which is simple in construction and operation, which can be erected and folded by its own power plant connected with the travelling block, and which requires no snub lines or the like to aid in the erection and folding of the mast.

In accordance with this invention, a reclining lower mast section has a foot pivotally connected to a base that may be mounted on a barge. This lower section extends forward over the base from the foot. Reclining above the lower section is an upper mast section that has a head at the back of the base. The front end of the lower side of the upper section is hinged to the front end of the upper side of the lower section. The upper side of the upper section extends forward beyond the hinge to overhang the underlying lower section. Pivoted legs, which are inclined lengthwise of the base, have upper ends pivoted to the overhanging portion of the upper section. The lower ends of the legs are pivotally connected to the base between the locations of the ends of the reclining lower section. Means are provided for swinging one of the mast sections upwardly. The lower ends of the legs are in a position to cause the legs to swing the other mast section upwardly relative to the first section until both sections are erect with the upper section resting on top of the lower section. Means may also be provided for then changing the position of the lower ends of the pivoted legs relative to the base sufiiciently to allow the two erect mast sections to swing forward under gravity from a position where the center of gravity of the upper section is behind the hinging means to drilling position where said center of gravity is in front of the hinging means.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a plan view of the folded mast;

FIG. 2 is a side view thereof;

FIG. 3 is a fragmentary side view of the erected mast;

FIG. 4 is a rear view thereof;

FIG. 5 is a fragmentary front view of the erected mast;

FIG. 6 is a line drawing showing the mast in erect drilling position;

FIG. 7 is a fragmentary side view of the front portion of the base; and

FIG. 8 is a vertical section taken on the line VIllVlIl of FIG. 7.

Referring to FIGS. 1 and 6 of the drawings, a base it of the skid base type has drawworks 2 mounted on it near its rear end. Such a base is adapted to be rigidly mounted on a trailer or on a barge (not shown). A pair of rear shoes 3 are mounted on the base at opposite sides of the drawworks, and the bifurcated foot of an upright mast is pivotally connected to these shoes. The mast is divided into two sections; a lower section 4 supporting an upper section 5. The lower section leans forward slightly. The two mast sections meet along an inclined plane extending upwardly and rearwardly from the lower end of the front side of the upper section. end of this plane the back sides of the two sections are hinged together on a horizontal axis by suitable hinge brackets 6. The mast is supported in upright drilling position by a pair of legs 7 that are pivotally connected at 8 to the lower end of the front of the upper section. The legs extend downward and forward from the mast, with their lower end portions pinned to brackets 9 mounted on the front end of the base. The head of the mast supports the usual crown block 11 (FIG. 6), from which a travelling block 12 is suspended inside the mast by a drilling line 13 that also extends from the crown block down the inside of the mast to the drawworks. This line passes in front of a horizontal roller 14 journaled in the back of the mast close to its hinge.

The mast will now be described in its folded position, as shown in FIGS. 1 and 2, for a better understanding of its construction and operation. In this position the lower section 4 of the mast is reclining and extends forward over the base from rear shoes 3 and it may project beyond the front end of the base. It can rest on a temporary support 16 on the base. The upper mast section reclines above the lower section and extends rearwardly from the hinge 6 and over a removable support 17, thereby locating the head of the mast at the back of the base. The upper side of the reclining upper section extends forward beyond the hinge to overhang the underlying lower section. The legs 7 are inclined downwardly and rearwardly from their connection to the upper section to the base at points between the ends of the reclining lower section.

For a purpose that will be explained presently, it is preferred that while the mast is folded the pivoted legs not be connected to brackets 9. Instead, the lower ends of the legs are connected to means by which their position can be changed in order to lower the legs relative to the base. Preferably, therefore, the lower ends of the legs are pivotally connected by pins 13 to the upper ends of vertical triangular front shoes 19, the lower ends of which are pivotally mounted on pins 20 secured in the lower part of the base behind brackets 9. The backs of the shoes are pivotally connected to piston rods 21 ex tending rearwardly into hydraulic cylinders 22, the rear ends of which are pivoted in the base at 23, as best shown in FIG. 7. It will be seen that the reclining legs extend from shoes 19 forward over the brackets.

The location of pivot pins 13 is such that when either mast section is swung upwardly, such as by lines connected to the upper section or by a hydraulic ram beneath the lower section, the legs 7 will swing the other mast section upwardly relative to the first section. Thus, the head of the mast will swing upward and forward as hinge 6 swings upward and backward. These movements will continue until the upper section is erect and rests on the lower section, to which it then can be bolted or clamped in any suitable manner. About the simplest way to erect the mast is by means of the drawworks and travelling block and the line 13 connecting them. In such a case, the hook 125 of the travelling block is connected to a sling 2 5 that extends forward over the front end of the upper side of the reclining upper section of the mast, such as over vertical sheaves 27 journaled in the front end of At the upper a the upper section. From these sheaves the sling, formed from a cable doubled on itself, extends downwardly to rigid means projecting forward from the reclining lower section. Preferably, such means is in the form of a framework 28 that is rigidly connected to the front end of the reclining lower section and that includes a pair of laterally spaced channel members 29, which extend forward from the lower section and then curve upwardly. The channel members are open at the bottom. The sling extends back through these channel members and has its opposite ends secured to the lower section, such as to brackets 30 attached to the upper part of the lower section. When the drawworks is operated to reel in line 13, the pressure of the sling against sheaves 27 swings that end of the upper section down around hinge 6, but that motion is restrained and controlled by legs 7 which simultaneously compel the adjoining end of the lower section to swing upward. Therefore, the upper end of the lower section swings backward at the same time as the upper end of the upper section swings forward, until the upper section is erect and rests on top of the lower section. The framework 28 is narrow enough to swing into the upper section of the erect mast.

It will be seen in FIG. 6 that if the mast were raised directly to the solid line drilling position in this manner, the center of gravity of its upper section would lie in front of hinge 6. In such a case the mast could not be folded again until its upper section had been swung backward on the hinge far enough to start swinging down by gravity, but such breaking of the toggle formed by the mast would require a line connected to the top of the mast, and means located some distance behind the mast for pulling the line. It is to avoid such a line and pulling means that is another feature of this invention. This is the reason for having the lower ends of legs 7 connected to shoes 19 instead of to brackets 9 during raising of the mast. Consequently, shoes 19 during erection are maintained in their full line position shown in FIGS. 7 and 2 so that by the time the erect upper mast section is seated on the erect lower section, the pivoted legs will have required the entire mast to be swung backward past its drilling position far enough for the center of gravity of the upper section to be located behind the mast hinge in the upper dotted line position in FIG 6, but preferably not far enough for the center of gravity of the mast as a whole to be behind rear shoes 3. After the two erect mast sections have been clamped together in this position, fluid pressure is delivered to the rear ends of cylinders 22 to cause the shoes 19 to be swung forward and down, to their dotted line positions shown in FIGS. 7 and 3, thereby lowering legs 7 and permitting the mast to swing or settle forward into upright drilling position, wherein the center of gravity of the upper section will be well in front of the mast hinge. Legs 7 then are pinned to brackets 9.

To fold the mast again, sling 26 is connected to the travelling block and put under tension, the gin pole legs then are unpinned from brackets 9, then the pivoted front shoes 19 are swung backward and up by the hydraulic cylinders to swing the mast back to its rear erect position where the center of gravity of the upper section again will be behind hinge 6, the upper and lower sections of the mast then are disconnected from each other in front of the hinge, and then the upper section 5 is allowed to swing backward and down by gravity but under the control of the travelling block and sling and pivoted legs. Simultaneously therewith, the lower mast section will swing forward and down as the travelling block is lowered in the upper section, with the result that the mast will fold itself over the base.

If desired, the front shoes 19 could be so designed and their movement made such that after the mast has been folded they could be moved forward into a position where they could be left while the mast is swung up directly to drilling position without first going past that point and having to be returned to it. The folding procedure would be the same as before, however; the front shoes would have to be moved to their rear position to cause the pivot-ed legs to swing the mast backward a few degrees before the upper section could start to fold under the influence of gravity. In either case, no outside lines or winch trucks are required for unfolding or folding the mast.

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 folded mast structure comprising a base having front and rear ends, a reclining lower mast section having a foot pivotally connected to said base, said section extending forward over the base from said foot, an upper mast section reclining above the lower section and having a head at the back of the base, means hinging the front end of the lower side of the upper section to the front end of the upper side of the lower section, the upper side of the upper section extending forward beyond said hinging means to overhang the underlying lower section, rigid, unitary legs inclined lengthwise of the base and having upper ends pivoted to said overhang, shoes pivotally connecting the lower ends of the legs to said base between the locations of the ends of the reclining lower section, and means for swinging one of the mast sections upwardly, the lower ends of the legs being held down by said shoes in a position to cause the legs to swing the other mast section upwardly relative to said one section until both sections are erect with the upper section resting on top of the lower section.

2. A folding mast structure according to claim 1, in which said swinging means include rigid means projecting forward from the reclining lower section, a sling connected with said rigid means and extending up over the front end of the upper side of the reclining upper section and then rearwardly down into that section, a travelling block in the upper section connected to the sling, and means for pulling the block toward the head of the mast.

3. A folding mast structure according to claim 2, in which said rigid means includes a pair of laterally spaced downwardly and forwardly opening channel members, and said sling is a cable doubled on itself and extending through said channel members with its opposite ends secured to the upper part of the reclining lower section, said channel members extending up into said upper section when the mast is erect.

4. A folding mast structure according to claim 2, in which said pulling means include drawworks mounted on said base adjacent said foot, a crown block mounted on said head, a line-supporting member mounted near said hinging means, and a line connected with the travelling block and extending rearwardly therefrom around said crown block and then forward and around said supporting member and then rearwardly to connection with the draw works.

5. A folding mast structure according to claim 2, including a pair of laterally spaced vertical sheaves journalled in the front end of the reclining upper section near its upper side, and said sling being a cable doubled on itself and extending over said sheaves and having its opposite ends secured to said lower section.

6. A folded mast structure comprising a base having front and rear ends, a reclining lower mast section having a foot pivotally connected to said base, said section extending forward over the base from said foot, an upper mast section reclining above the lower section and having a head at the back of the base, means hinging the front end of the lower side of the upper section to the front end of the upper side of the lower section, the upper side of the upper section extending forward beyond said hing- .5 ing means to overhang the underlying lower section, legs inclined lenghtwise of the base and having upper ends pivoted to said overhang, means pivotally connecting the lower ends of the legs to said base between the locations of the ends of the reclining lower section, means for swinging one of the mast sections upwardly, the lower ends of the legs being in a position to cause the legs to swing the other mast section upwardly relative to said one mast section until both sections are erect with the upper section resting on top of the lower section in a position where the center of gravity of the upper section is behind said hinging means, and means for then changing the posi tion of said leg-connecting means relative to the base sufficiently to allow the two erect mast sections to swing forward together to upright drilling position with said center of gravity in front of the hinging means.

7. A folding mast structure according to claim 6, in which said leg-supporting means are shoes pivotally connected to said legs and base, said structure including means for swinging the shoes on the base to a position in which the legs will allow the two erect mast sections to swing forward to said drilling position.

8. A folding mast structure according to claim 7, in which the bottoms of said shoes are pivotally connected to the base, the tops of the shoes are pivotally connected to the legs, and said shoe-swinging means swing the shoes forward and down to move the adjoining ends of said legs forward and down to a lower position.

9. A folding mast structure according to claim 7, in which said shoe-swinging means are fluid pressure operated rams behind the shoes.

10. A folding mast structure according to claim 7, including means for detachably connecting said legs to the base in their forward position.

11. A folded mast structure comprising a base having front and rear ends, a reclining lower mast section having a foot pivotally connected to said base, said section extending forward over the base from said foot, an upper mast section reclining above the lower section and having a head at the back of the base, means hinging the front end of the lower side of the upper section to the front end of the upper side of the lower section, the upper side of the upper section extending forward beyond said hinging means to overhang the underlying lower section, legs inclined lengthwise of the base and having upper ends pivoted to said overhang, shoes pivotally connected to the lower ends of said legs and to said base between the locations of the ends of the reclining lower section, rigid means projecting forward from the reclining lower section, a sling connected with said rigid means and extending up over the front end of the upper side of the reclining upper section and then rearwardly down into that section, a travelling block in the upper section connected to the sling, means for pulling the block toward the head of the mast to swing the upper section upwardly, said shoes being in a position to cause the legs to swing the lower section upward on said foot until both mast sections are erect with the upper section resting on top of the lower section in a position where the center of gravity of the upper section is behind said hinging means, and means for swinging said shoes forward on the base to a position in which the legs will allow the two erect mast sections to swing forward together to upright drilling position with said center of gravity in front of the hinging; means.

References Cited by the Examiner UNITED STATES PATENTS 2,573,528 10/ 1951 Woolslayer et al. 52117 X 2,683,584 7/1954 Selberg 52116 X 3,033,527 5/1962 Wilson 52-116 X 3,181,658 5/1965 Bender 52116 FOREIGN PATENTS 942,619 5/ 1956 Germany. 738,198 10/ 1955 Great Britain. 65,418 6/ 1913 Switzerland.

FRANK L. ABBOTT, Primary Examiner.

R. S. VERMUT, Assistant Examiner.

Claims

1. A FOLDED MAST STRUCTURE COMPRISING A BASE HAVING FRONT AND REAR ENDS, A RECLINING LOWER MAST SECTION HAVING A FOOT PIVOTALLY CONNECTED TO SAID BASE, SAID SECTION EXTENDING FORWARD OVER THE BASE FROM SAID FOOT, AN UPPER MAST SECTION RECLINING ABOVE THE LOWER SECTION AND HAVING A HEAD AT THE BACK OF THE BASE, MEANS HINGING THE FRONT END OF THE LOWER SIDE OF THE UPPER SECTION TO THE FRONT END OF THE UPPER SIDE OF THE LOWER SECTION, THE UPPER SIDE OF THE UPPER SECTION EXTENDING FORWARD BEYOND SAID HINGING MEANS TO OVERHANG THE UNDERLYING LOWER SECTION, RIGID, UNITARY LEGS INCLINED LENGTHWISE OF THE BASE AND HAVING UPPER ENDS PIVOTED TO SAID OVERHANG, SHOES PIVOTALLY CONNECTING THE LOWER ENDS OF THE LEGS TO SAID BASE BETWEEN THE LOCATIONS OF THE ENDS OF THE RECLINING LOWER SETION, AND MEANS FOR SWINGING ONE OF THE MAST SECTIONS UPWARDLY, THE LOWER ENDS OF THE LEGS BEING HELD DOWN BY SAID SHOES IN A POSITION TO CAUSE THE LEGS TO SWING THE OTHER MAST SECTION UPWARDLY RELATIVE TO SAID ONE SECTION UNTIL BOTH SECTIONS ARE ERECT WITH THE UPPER SECTION RESTING ON TOP OF THE LOWER SECTION.