US1871132A

US1871132A - Derrick having fluid load-equalizing means

Info

Publication number: US1871132A
Application number: US510698A
Authority: US
Inventors: Leslie A Rawson
Original assignee: Emsco Derrick and Equipment Co
Current assignee: Emsco Derrick and Equipment Co
Priority date: 1931-01-23
Filing date: 1931-01-23
Publication date: 1932-08-09
Anticipated expiration: 1949-08-09

Description

Aug. 9, 1932. A. RAWSON 1,871,132

DERRICK HAVING FLUID LOAD EQUALIZING MEANS Fil ed Jan. 25. 1951 2 Sheets-Sheet 1 Au 9, 1932. A W N 1,871,132

DERRICK HAVING FLUID LOAD EQUALIZING MEANS Filed Jan. 23, 1951 2 Sheets-Sheet 2 x 4" I i i M//////////// E W I 49 64/6 flEnu sq/v 2y I W 4 7TOE/v5 Y.

Patented Aug. 9, 1932 LESLIE A. RAWSON, or Los AneELns, cAmroiinIA, assrenoa T E s'oo nsertion & EQUIPMENT COMPANY, or LOS ANGELES, CALIFORNIA, A icoiaronn'rron or CALIFORNIA DERRICK HAVING snare LoAb=EairALIiInG Application fil'ed an ry 23, 19:51; sear N6. s'iaas.

My invention relatesto a derricksuch as is used in the oil-producing industry, and particularly to a derrick having double leg constructions which extend from" the base to the crown oi the 'derrick. In derricks of this type one of th legs of the donble leg constructions is removable and is used during drilling operations when the loads imposed in the derricks are considerable, and is not re used during the pumping periods of the well when the load imposed on the derrick is relatively light. 7

Best results are obtained ina derrick of this construction if the load is properly pro: portioned between the legs of the double leg constructions. The outer leg which isu'suah ly the permanent leg, and which we will for convenience call a primary leg, is design-ed'to support with safety any loads imposed on the derrick during pumping operations? The inner leg which is usually the removable leg, and which for convenience we will call; a secondary leg, is designed to support with safety the additional load imposed on the derrick during drilling operations.

for reasons of safety, as well as for reasons of economy, that each leg of the double leg construction, that 1s, the primary and second my legs, take the proportion of theload whichit is designedto carry. In the ordi nary types of double leg constructions with" which applicant is familiar one of the legs is adjustable in length, and after the derrick ment of this leg is made by one of the workmen, and on many occasions theworkmans ]udgment has been greatly 1n error andilnreferred to which includes ameans which automatically proportions the load onthe primary and secondary legs of the doubl-e leg construction of the derrick. My inven- 5w tion absolutely eliminates-the" human ele- It? will therefore beseenthat it is highly desirable,

is assembled this adjustable leg is lengthened so as to take part of the load. The adjust tense strains have been placed on on'eof the" legs of the derrick which has resulted not men't from the proportiohing of the,load and assures thatat all times during the operation of the derrick with the double leg con:

struction the primary leg will take its intended proportion of th Na i the, l l' ondary leg will also take its intenddjprophr tion" of the load. Inthisway both of the legs will be made to do the. work they are designed to do and neither leg will'be called upon to carryloads whichreduce their fa'ct'or e' 'y-, a,

My present invent-n 1 dire ted in a com; bination which includes a crown, a base, and

a double leg construction extending from the base to the crown, in com binatioil with fluid means for proportioni'ng the load between the legs. By fiuidmeansfis meant any means which yields to force tend; ing to change'itsform, and whaiahearm' fluid is used Iintend to" meanthsubstance of this nature. For example, I intend the term to include a gas, liquid, ora semisolid, such as very soft rubber, which has the c'haracter'istioof readily changing its form when a pressureis applied to it. 7 Theequalizing means which lSj PIO V ldBd bym'y-inventiori may be placed between the pper e of t e i an ihr mwnrsrae derrick; or be placed between the lower ends of the legs and the. basejof thede'rric'k, or the equalizing means might be placedpart ly between one leg and the crown of the der r'ickand between another v leg and the base of the de1"1"ick. This latter construction would beimpractical but'is' within the" scope ofth-e inventions I V l V I, p r Inthe preferred form" of'my invention): utilize a pair of cylinders anda pair offp'is tons, in wliichcylinder s is a'fliquid', com: manic-anon is provided between'the cylinders in order that the liquid-in bahr thecyli n ders will be of the same'fpressiirefg Oiiefcyl? inder andpiston is associated with ofieofthe legs "of the derrick and either the crown or the base thereof, and the other. cylinder piston is associated with the other leg-ef the derrick; and either .th-e crown or the base: thereo' fi Whenjthe load is'fimpose'df on :the"

the area of cross secnon' oftli pistons." This Jan is true since the pressure of the fluid in both of the cylinders is the same. By making one cylinder and piston larger in diameter than the other, it is possible to cause one of the legs to take a greater proportion of the load than the other of the legs.

When the invention is used with a fluid substance, such as a very soft rubber, in place of the liquid, it is obvious that the communication between the cylinders must be of sufl'icient area to allow the rubber to be readily displaced from one cylinder to another.

One of the important advantages and featuers of the invention is that by reason of the fluid connection between the legs of, the derrick and either the crown or the base there of considerable vibration and shock to the parts areeliminated.

In the following detailed description various objects and advantages of the invention will be pointed out.

Referring to the drawings in which my invention is illustrated,

Fig. 1 is; an elevational view of a derrick, the central. part thereof being removed, and

' the upper part being moved downward toward the lower part in order that the base and crown may be illustrated.

Fig. 2 is a sectional view taken on the line 22 of Fig. 1.

Fig. 3 is an elevational view showing a double leg construction of my invention.

Fig. 4 is an elevational View of the equalizing means which I provide.

Fig. 5 is a section taken on the line 5-5 of Fig. 3. v Fig. 6 is a section taken on theline 6-6 of Fig. 5

' Fig. 7 is a view taken on the line 77 of Fig. 3,.

Fig. 8 is a sectional view through an alternative equalizing means of. my invention.

Referring to the drawings in detail, the derrick in which my invention is incorporated hasa base structure 11, a crown structure 12, and a plurality of double leg constructions 14. According to usual practice, there is a double leg construction placed in each corner of the derrick, and each leg construction extends from a corner of the base structure 11 to a corner of the crown structure 12. In view of the fact that .the four leg constructions are identical both in construction and operation, in the ensuing description I will describe but one double leg construction, but it should be clearly understood that the description applies equally as well to the other three double leg constructions of the derrick.

Referring particularly to Figs. 3 to 6 inclusive, each double leg construction includes a primary leg 16 and a secondary leg 17. The primary leg 16 is preferably made of a single band and is installed in the derrick, the flanges of the single band extending parallel to the sides of the base and crown structures primary leg 16 is associated with an equalizing means 19 which is interposed between the upper end of the double leg construction 14 and the crown structure 12. The details of the equalizing means 19 will be described later. The secondary leg '17 is preferably tubular in cross-section and-is conveniently positioned within the primary leg 16, as is best shown in Fig. 7, being retained in this position by suitable holding devices 26. The lower-end of the secondary leg 17 is provided with a spherical, head 29 which rests in a socket 30 provided by the corner piece 18; The upper end of the secondary leg 17 isassociated with the equalizing means 19.

The primary leg 16 is a permanent part of the derrick and is used notonly during drilling operations but also during pumping operations in the well. The secondary leg 17 isa removable leg and is used only during drilling operations in the well. When the drilling operations are completed and the der rick will nolonger be called upon to carry enormous loads, the secondary leg 17 may be removed. v

I will now describe the equalizing means of my invention and to do this will refer particularly to Figs. 5 and 6.

The equalizing means 19 includes a body or headpiece 35 having an upper flat surface 36 on which the crown structure 12 rests.

cylinder 38. These'cylinders are closed at the top but are opened at the lower part of the body 35. F urthermore, the cylinders are intercommunicated by passages 39, shown best in Fig. 5. Secured to the primary leg 16 is a piston structure 40 which includes a bracket portion 41, by means of which it is secured to the primary leg 16. Suitable bolts 42, shown in Fig.6, are provided for this securement. Extending upward from the bracket 41 is a pair of vertical and parallel piston rods 43 which are spaced so that their axes coincide with the axes of the primary cylinders 37'. Form-ed on the upper ends of the piston rods 43 are primary pistons 44 which, as illustrated, extend into the primary cylinders 37. Associated with the upper end of the secondary leg 17 is a secondary piston structure 46 which has a lower projection 47 which extends into the upper end of the secondary leg 17 and has a shoulder 48 whichbe conveniently removed without taking;

apart any of the structure in the crown of the derrick. Extending upward from the parts just described is a piston rod 49 which is ar ranged on an axis in axial alignment with the axis of the secondary cylinder 38. On the upper end of the piston rod 49 is asecondary piston 50 which rests in the secondary cylinder 38. In order to guide the. piston rods, packing nuts 53 are threadedly secured in the lower ends of the primary and

secondary cylinders

37 and 38. These packing nuts have cylindrical open ngs 54 through which the

piston rods

43 and 49 are extended. Fluid maybe introduced into the cylinders through an opening 56 closed by a plug 57a When a load is imposed on the crown structure of the derrick, the corner pieces or bodies 35 are pressed downward and'the fluid contained in the primary and secondary cylinders is placed under a pressure.

The pressure per square inch of the fluid is the same in each of the

cylinders

37 and 38. The pressure therefore applied to the primary leg or the secondary leg depends entirely upon the cross-sectional area of the primary pistons 44 and the secondary piston 50. By proportioning the cross-sectional areas of these pistons it is possible to proportion the load between the primary and secondary legs of the derrick. When the derrick is no longer called upon to handle enormous loads, the secondary leg 17 of each double leg construction 14 may he removed. When this leg is removed the secondary plunger structure 46 is of course not in use and merely hangs from the secondary cylinder 38,. being supported by the packing nut of that cylinder. The primary piston construction 40 at this time takes the entire load and transfers it to the primary leg of the derrick.

In the form of the invention just described I prefer to use a heavy mud, such as oil or glycerine, and prefer to place the equalizing means in the upper part of the derrick immediately below the crown structure 12. My invention is not limited to the details shown in Figs. 1 to 7 inclusive, since various modifications might be made. would be possible to place an equalizing means between the double leg construction 14 and the base structure 11 of the derrick. Also, it is possible to attach the piston struc- "tr-.res-tov either the crown structure or the base structure of the derrick, and to attach the cylinders to the primary and secondary legs. If this were done, it would be necessary to make the cylinders separate in order that they would be relatively movable. In this event, it would be necessary to have an intercommunication between the cylinders, and this could be done by forming a channel in the piston structure which could be made in one piece or by providing a flexible connection between the cylinders. Furthermore, it is not necessary to use a pair of primary cylinders. This is done in the preferred form of my invention solely for the purpose of con- For example, it

venience and to obtain a more practical design.

In Fig. 8, I illustrate a form of my invention in which, in place of using a fluid, such as oil, glycerine, or gas, I use a very soft or fluid substance such as a soft rubber. In this figure the numeral 60 represents a body of fluid substance which is placed in the primary and secondary cylinders '37 and 38, there bein g communicating passages'61 between these cylinders. The body 60 is shaped to conform closely to the configuration of these cylinders and the passages 61. The operation of this form of the invention is substantially the same as in theform of my invention previously described. In this form, the communie eating passages v61 must be of. sutficient area to allow the body of fluid substance to be readily displaced from one cylinder to an other.

I believe my invention to be broadly new in the provision of a derrick which includes a fluid means for proportioning the load between a plurality of legs of the derrick. This is the broad concept of my invention. The particular design which I utilize also in cludes features of my invention, and I desire protection on these features as well as the broad concept of my invention.

In the claims I have employed the term thrust receiving member, and by such term I refer either to the lower wall of the corner piece 18 or to that portion of the crown block 12. which receives thrust from the equalizing device. It will be clearly understood from the standpoint of mechanics that the legs exert an upward thrust on thecrown construction 12 which is a direct reaction of the thrust imposed by the crown constructtion 12 on the leg construction. Likewise, the leg construction exerts a thrust on the corner piece 18, while the corner piece 18 exerts w an opposite reactional thrust against the leg construction. I also employ the term means for connecting the body of the equalizing means to the crown. construction. This means in the form of my invention disclosed is the flange 36 formed on the upper part of the body 35- and the flanges which constitute the superimposed portion of the crownconstruction- 12. This means phrase is a broad term and is intended to cover any equivalent means whereby the one part is connected to the other. i

I claim as: my invention:

1. In. a derrick, a base structure, a; crown structure, and a. leg construction extending between said base and crown structures, said structure, and a leg constructionextending between said base and crownstructures, said leg construction including a primary and a secondary leg, the combination of: equalizing means associated with said legs and one of said structures, said equalizing means providing primary fluid means associated with said primary leg and one of said structures, and secondary fluid means associated with said secondary leg and one of said structures.

3. In a derrick, a base structure, a crown structure, and a leg construction extending between said base and crown structures, said leg construction including a primary and a secondary leg, the combination of: equalizing means associated with said legs and one of said structures,:said equalizing means providing a primary cylinder and piston associated with said primary leg and one of said structures, a secondary cylinder and piston associated with said secondary leg and one of said structures, and a fluid substance in said cylinders.

at. In a derrick, a base structure, a crown structure, and a leg construction extending between said base and crown structures, said leg construction including a primary and a secondary leg, the combination of: equalizing means associated with said legs and one of said structures, said equalizing means providing a primary cylinder and piston associated with said primary leg and one of said structures, a secondary cylinder and piston associated with said secondary leg and one of said structures, anda fluid substance in said cylinders, there being intercommunicating means between said cylinders.

5. In an oil wellderrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a body of fluid; and means for confining said fluid under pressure in such a manner that said fluid transmits the thrust of said legs to said member.

6. In an oil well derrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a

body of fluid; and means for confining said fluid under pressure in such a manner that said fluid transmits the thrust of said legs to said member and imposes a definite proportion of said thrust on each leg. 7

7 In an oil well derrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a body of fluid; a fluid confining structure having a cavity containing said fluid and adapted to withstand the pressure of said fluid; means for connecting said structure to said member in such a manner that itcan' exert thrust thereon; and means by which the thrust of each of said legs is transmitted to said fluid.

8. In an oil well derrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a

bo-dyof fluid; a fluid confining structure hav ing a cavity containing said fluid and adapted to withstand the pressure of said fluid; means for connecting said structure to said member in such a manner that it can exert thrust thereon; and means by which the pressure of said fluid imposes a definite proportion of said thrust on each leg.

9. In an oilwell derrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a body of fluid; a stationary means containing a cavity in which said fluid may be confined; a movable means sliding-in said stationary means and acted upon by the pressure of said fluid; and means by which the thrust produced between said stationary means and said movable means istransmitted in one direction to said member and in the other direction to said legs.

' 10. In an oil well derrick having a primary leg, a secondary leg, and a thrust receiving member, and in combination therewith: a body of fluid; a stationary means containing a cavity in which said fluid may be confined; a movable means sliding in said stationary means and acted upon by the pressure of said fluid; and means by which the thrust produced between said stationary means and said movable means is transmitted in one direction to said member andin the other direction to said legs, the thrust transmitted to said legs being divided therebetween in a definite proportion.

11. In an oil well derrick having a leg and a thrust receiving member and in combination therewith:a body of fluid; a fluid retaining structure in which said fluid may be held under pressure; thrust transmitting means movable with relation to said structure and adapted to be acted upon by said pressure to thrust said thrust transmitting means away from said structure; and means for transmitting the thrust developed between said thrust transmitting means and said structure to said thrust receiving member and said leg.

In testimony whereof, I have hereunto set my hand at Los Angeles,-California, this 30 day of December, 1930.

LESLIE A. RAVVSON.

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