US 1935095 A
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Description (OCR text may contain errors)
' Nov; 14, 1933. A, w L l 1,935,095
DERRICK CONSTRUCTION File d March 7, .1932 1 2 Sheets-Sheet I ATToe/vB Patented Nov. 14, 1933 UNITED STATES PATENT OFFICE DERRICK CONSTRUCTION Arthur W. Lewis, La Canada; (Jali!., assignor to Petroleum Derrick Co. Ltd, La Canada, CaliL, a corporation of Nevada v My invention relates to oil well derricks fabricated from structural steel members. Such der ricks are in general use throughout the world and are fabricated by many manufacturers. All of these manufacturers, so far as I am aware, have adhered closely to standard tower design, using four leg members connected by girts, which encircle the derricks, and diagonal cross bracing members, each member of which extends from the junction of a girt with a leg to the junction of an adjacent girt on an adjacent leg, the cross bracing members crossing each other at approximately the center of the panel formed by the two girts and the two legs.
In steel derricks of all kinds with which I am. familiar, including the derrick described herein, the corner legs are designed to carry the entire vertical load. In addition to this vertical load, such derricks are subjected to certain loads producing horizontal stresses in the derrick. Such stresses for example are produced by the drill pipe which is not in use and which rests upon the derrick door and leans against the upper portion of the derrick. Since several thousand feet of pipe in long stands are constantly so stored, the horizontal component of force produced thereby on the derrick is considerable.
In addition to this component the derrick in times of high wind is subjected to horizontal loadis eliminated and in which a novel arrangement of diagonal bracing is used. By this novel arrangement I am able to produce a derrick having the same ability to resist the forces to which a derrick issubjected as the conventional form of derrick but in which a considerable saving in weight of material over that used in the conventional derrick is possible due to a better utilization of material.
In derricks of my invention the diagonal members are also depended upon to resist the horizontal load components imposed on the derrick, but these diagonal members are in compression. Derricks constructed in accordancewith my invention are not only more economical in material usedin their construction than conventional derricks but are much more rigid, due to the open 'showing'the preferred form of derrick embodying my invention.
Fig. 2 is an elevation of side of said derrick.
Fig. 3 is an elevation of the calf wheel'side of said derrick.
Fig. 4 is an enlarged view showing one method of connecting the various derrick members.
Fig. 5 is an elevation showing a center six point connection.
Fig. 6 is a view showing a corner six point diagonal connection as it would appear were that portion of the structure shown to the left of the line a--a turned 90 towards the plane of the paper from its actual position.
Fig. 7 is a section through one of the legs.
Fig. 8 is a section taken as indicated by the line b--b of Fig. 6;. this figure, however, is not distorted from its normal plane.
In the drawings I have illustrated a derrick of the proportions usually employed in well drilling rigs, the derrick having four sides and being substantially larger at its base than at its upper end. I have illustrated a construction suitable for a derrick in the neighborhood of 120 feet so high and intended to carry various units of drilling equipment, such as a crown block, drawworks, etc.
The derrick illustrated, being four-sided, includes four legs 10. In accordance with the present invention, horizontal girts 11 are provided at each side of the derrick to extend between. the legs 10, diagonal members 12 are provided between the girts 11 and the legs 10, and various other features of construction are provided, as will be hereinafter described.
The legs 10 of the derrick are located at the corners of the structure and extend from the base 1 to the upper end. Each leg 10, in accordance with my invention, involves three principal parts, namely, two main flanges 13 lying in the planes of the adjoining sides of the derrick, and an outer flange 14 projecting outwardly from the point of intersection of the main flanges 13. The
theladder and pump -'main flanges together form an angle-shaped structure, each main flange for a part to which the girts and diagonal members of the structure may be connected. The outer flange 14 projects. outwardly from the corner formed by the main flanges so that there are equal angles between the outer flange and the two main flanges,'as clearly illustrated in Fig. 'l of the drawings. The outer flange 14, because of its relationship to the main flanges, adds a sub stantial amountof strength and rigidity to the leg by the addition of but little material to the structure formed by the main flanges alone.
In accordance with the preferred form of the invention, each leg is of sectional construction, 1. e., the legconstruction just described is in two sections, the line of division being through the center of the outer flange 14: in the plane of the outer flange, so that each leg section includes a main flange and an outer flange part 14. When the leg is assembled, as shown throughout the drawings, the flange parts la abut and are secured together as by bolts 15, or the like. In
practice, bolt holes are provided at suitable in-.
tervals throughout the lengths of the flange parts 14 and the bolts 15 are applied to secure the flange parts 1 together as the derrick is as sembled. A feature of the sectional leg construc= tion just described is that the sides of the der= rick can be assembled on the ground in sections of suitable length and then moved into position to be secured by coupling the flange parts 14 of the legs through the bolts 15.
In the structure of the present invention, there are several horizontal girts 11 at each side of the derrick. The girts 11 are arranged to extend between opposing main flanges 13 of the derrick legs and are vertically spaced. The girts 11 may be formed of angle iron and may be connected to the main flanges 13 of the legs through joints or connections such as I will hereinafter describe.
The invention provides a novel and eflective arrangement of diagonal members 12 between the legs 10 and horizontal girts 11. In accordance with the invention, there are four diagonal braces located in each space defined by adjacent legs of the derrick and adjacent girts 11 extending between said legs. The diagonal members 12 are connected to the opposing main flanges 13 of the said derrick legs at points intermediate the points of connection between the horizontal girts and the legs. Diagonal members A extend from their point of connection with the derrick legs upwardly and inwardly to a point where they adjoin each other and connect with the middle portion of the upper girt 11, while diagonal members B extend from their point of connection with the legs downwardly and inwardly -to a point where they adjoin and connect with the lower girt 11. This arrangement of parts is clearly illustrated in Figs. 1, 2, and 3 of the drawings. The diagonal members A and B are preferably formed of angle iron and are connected with the leg flanges and the girts through connections such as I will hereinafter describe. In the case illustrated, the diagonal members are shown connected directly to the leg flanges 13 and are shown connected to gusset plates 16 attached to the horizontal girts by bolts 17. The diagonal members 12 of the construction are active or load-carrying parts of the structure and, when the derrick is under a strain, these members act either under compression or tensiofl. By supporting the diagonal members 12 intermediate their ends, a given load capacity can be gained by the use of lighter members than aesaecs the diagonal members and extend to points ad- 3 jacent the points of connection between the horizontal girts 11 and the legs 10.
It is to be noted that the braces 18 that may be employed to permit of the use of light diagonal members are comparatively short and form. but a small portion of the derrick structure.
The framing and bracing at the lower part of the derrick may vary considerably from the main derrick construction that I have hereinabove described in order to accommodate equipment such as may be employed in connection with the derrick. In the drawings, I have shown framing below the horizontal girts C suitable for .units or? equipment such as are commonly employed in the drilling of oil wells.
My present invention provides a joint or con nection for coupling the ends of the angle iron members with the other parts, for instance, with the leg flanges and the gusset plates. In accordance with my invention, a reinforcing member 20 is applied to the end portion of the angle iron, being connected to the member, and a bolt 21, or the like, connects the reinforcing member and one flange of the angle iron to the member to which the angle iron is connected, while a bolt 22 connects the reinforcing member with the other flange of the angle iron. The reinforcing member may be an angle-shaped part designed to flt into the angle iron and having flanges 23 fitting against the inner sides of the flanges of the angle iron. The main connecting bolt 21 which joins the. angle iron to the member to which it is to be connected joins two flanges and the reinforcing member to the angle iron. The bolt 22 joins the other flange of the angle iron to the other flange 23 of the reinforcing member. Through the medium of the reinforcing member and the bolts 21 and 22, the second or otherwise unsupported flange of the angle iron is connected with the member to which the angle iron is con= nected, thus developing the strength of both flanges of the angle iron. In addition to the bolt 21, the reinforcing member 20, the angle, and the member to which the angle iron is connected may be connected through a lug 2% formed on one 1 ltl flange 23 of the reinforcing member to project of the derrick can be assembled on the ground and lifted into place, where they may be made secure by the bolts 15 joining the flange parts 14 of the leg sections. It is to be noted that the outwardly projecting flange parts 14 are angularly disposed so that a side section of the derrick can be readily moved inwardly into position so that it is guided by the flange sections 14 of the adjoining sides of the derrick and that the leg parts requiring connection, 1. e., the flange parts is, are located so that the bolts 15 can be readily applied.
It will be noted that the diagonal members 1122 form six point (or member) connections at the points indicated by the dotted circles at we and 101 in Fig. l. The connections at point 100 are shown in Fig. 5, and the connections at point 101 are shown in Fig. 6.
Referring to Fig. 5 it will be seen that forces are distributed from the point 102 in six direc tions, due to the six members which radiate 'iZro this point (the girt i1 acting as two of these members).
Referring to Fig. 6 it will be seen that forces are distributedfrom the point 103 in six directions, due to the six members which 1'11:- from this point (the leg is acting as two of these members).
The derrick in fact consists of legs and (lieg onal members, each of the diagonal members terminating at each end in a six point connection.
ese diagonal members difier from the corn ventional cross bracing foundin all sorts of strnc= tures in that they act in compression to resist horizontal forces.
It will further be noted. that in the embodiment of my invention, as shown in Fig. 6, the diagonals of one side are definitely positioned with relation to the diagonals of an adjacent side, that is all the diagonals at one end or the other terminate at a six point connection which is de up of the legs, two diagonals from one side and two diagonals from another side. This six point system or bracing gives great stifiness to the derrick with a um use of material.
I claim as my invention:
i. In an oil well derrick, the combination of:
iour leg members; girt members arranged in sets of four extending around the-derrick in the same plane and being connected at their ends to said legs; and diagonal members each extending from and connected toadjacent legs, said diagonal members being so placed that they form with the girts six point connections at the centers or said girts and that they form with the legs six point connections on said legs at a point midway between the planes oi adjacent girts.
2. In an oil well derrick, the combination of: tour leg members; gilt members arranged in sets or tour extending around the derrick; in the same plane and being connected at their ends to said legs; diagonal members each extending from and connected to adjacent legs, said diagonal inexn= hers heing'so placed that they form with the sirts six point connections at the centers of snid. sirts and that they form with the legs sis: point connections on said legs at a point midway between the planes of adjacent girts; auxiliary hraces substantially perpendicular to said diagonal members, each of said braces extending from the junction of a girt with a leg to a point on 'a diagonal brace midway between thegirt and the leg; and means for securing one end of said brace to said leg and the other end oi said brace to said diagonal member.
, ARTHUR Wu Hit