US2359919A - Crown block - Google Patents

Description

. Oct 10, 1944. G. D. JOHNSON 2,359,919

CROWN BLOCK Filed July 5, 1943 2 Sheets-Sheet 1 //7 Yen/3r 670m 19. fo/msw? Oct. 10, 1944. G; D. JOHNSON CROWN BLOCK Filed July 5, 1943 2 Sheets-Sheet 2 y WM Patented Oct. 10, 1944 UNITED STATES PATENT OFFICE CROWN BLOCK Application July 5, 1943, Serial No. 493,583

15 Claims.

This invention relates to a crown block for use on derricks such as are employed in the drilling of wells. It is a general object of this invention to provide a simple, sturdy and practical crown block possessing many features desirable in a structure of this kind.

A primary object of my invention is to provide a crown block in which the several lines depending to the traveling block are arrange-d and located to support the traveling block in a most advantageous manner, while the fast line is remote from the other lines, allowing it to be outside of the derrick Where that is desired.

It is desirable in certain derricks to provide a simplified and compact construction. With the usual crown block employed in or on derricks, all of the lines, including the fast line, depend within the derrick, making it necessary to construct the head of the derrick large enough to accommodate all the lines and to locate the hoisting mechanism so that the fast line is handled within the derrick at the floor thereof. By my present invention I provide a crown block which possesses the general desirable characteristics of the conventional crown block and, in addition, provides for operating the fast line at the exterior of the derrick. This allows the head of the derrick to be made compact, places no limitation on the base portion of the derrick construction and thus, generally, simplifies the entire rig.

Another object of my invention is to provide a crown block construction whereby all of the lines to the traveling block depend at the same angle, minimizing any tendency for irregular operation of the traveling block.

It is a further object of my invention to provide a crown block of the character referred to in which the sheaves are spaced across the block so that there is nearly equal side spacing between the depending lines. I accomplish this through my present invention without waste of space and without padding the construction to bring about this feature.

Another object of my invention is to provide a crown block of the character mentioned in which the fast sheave is considerably larger in diameter than the others so that it turns considerably slower than it would were it of the same size as the other sheaves.

Another object of my invention is to provide a crown block of the character mentioned which is extremely simple and economical of manufacture. I have provided a crown block embodying the desirable features above noted without employing complicated or extensive construction. The block of the present invention includes few parts and these are simple of construction and are extremely simple to handle.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of the upper end portion of a simple derrick showing the crown block provided by my invention applied thereto and showing a traveling block supported in the derrick by lines depending from the crown block. Fig. 2 is an enlarged detailed sectional View illustrating the mounting of the fast line sheave, being a view taken substantially as indicated by line 2-2 on Fig. 3. Fig. 3 is a, plan view of the crown block provided by my invention, parts being broken away at the horizontal plane of the sheave supporting shaft of the block to show the gen eral relationship of the regular sheaves and of the fast line sheave, and the mounting means provided for the various sheaves, and Fig. 4 is a View of the block shown in Fig. 3 being a view taken substantially as indicated by line 44 on Fig. 3, certain parts being broken away to show the section.

The crown block provided by my invention is suitable for use generally where devices of this character are employed, but it is particularly useful as applied to well drilling derricks and in that connection it is particularly useful on derricks where compact construction is important. In the drawing I have illustrated a typical application of the crown block and in this connection have shown the upper end portion of a derrick it! which includes the usual rectangular crown block platform ll, legs l2, gusset plates l3 and diagonal braces Hi. In the drawings I have shown only enough of the derrick IE! to facilitate an understanding as to the manner in which my crown block may be applied to such a structure.

The crown block provided by my invention includes, generally, a frame l5, a series of regular sheaves IS, a fast line sheave ll, a single shaft [8 carrying the several sheaves, and shaft mountings I9 supporting the shaft from the frame i5.

The frame of the block may, in acorclance with the broader aspects of my invention, be any suitable structure forming a base for the working parts and applicable to the head or platform of the derrick Hi. In the preferred form of the invention the frame 15 is a rectangular structure corresponding in plan configuration to the size and shape of the crown block platform of the derrick ID. The frame l may be advantageously formed or built up of a pair of lower beams 23 adapted to rest on the crown block platform I l of the derrick at what I will term the front and rear sides of the derrick and upper beams 2| which rest on and extend between the ends of the lower beams 20 so that they are spaced above or over what may be termed the sides 22 of the crown block platform of the derrick. The upper and lower beams of the frame may be fixed 01' secured together in any suitable manner to form a rigid structure and, in practice, may be suitably secured to the head of the derrick.

The simple, yet effective, frame construction which I have provided supports the working parts, that is, the shaft and sheaves, above the head of the derrick so there is ample working clearance for the sheaves and the lines that depend therefrom. It will be noted that the frame is not only simple of design and general construction but that it is such that it can be advantageously formed of standard structural shapes.

The regular sheaves l5 of the present block may be alike in size and construction. By making these sheaves uniform in size and by arranging them side by side on the main portion 24 of the shaft, the lines which depend therefrom are in two groups, a front group A which lies in a common plane at the front or forward side of the derrick and a rear group B, which lies in a common plane at the rear side of the derrick. It wil lbe noted from Fig. 1 of the drawings that the regular sheaves are of such size withrelation to the opening in the head ofthe derrick that the groups A and B of lines pass downwardly inside the derrick to the traveling block25.

In the particular block illustrated in the drawings there are four regular sheaves I6 alike in size and construction. The rims 25 of the sheaves are shaped to carry the line while the hubs 21 are made to accommodate bearings 28 by which the sheaves are mounted on the portion 24 of the shaft [8. V

The series of regular sheaves 56 are located in the block construction so that they adjoin one of the shaft mountings [9. As shown in Fig. 4 of the drawings, the shaft mounting i9 adjoining the series of regular sheaves I6 is provided with a flange 29 which operates to overhang the hub of the end sheave and to enclose the bearing thereof.

The fast line sheave I1 is located around the shaft l8 between the series of regular sheaves l6 and the other shaft mounting l9. This places the fast line sheave at one end or side of the block which is the proper location for receiving the fast line.

The fast line sheave I I is supported by the shaft 13 but not concentric therewith. This sheave i considerably larger in diameter than the regular sheaves and is mounted eccentric to the shaft IS in a horizontal direction so that the portion or side of the sheave which receives the fast line is removed a substantial distance laterally of the other lines of the block, while the opposite side of the sheaves is in line with the sheaves I 6 so that the line therefrom is in group A. Ln accordance with my invention this offset or lateral displacement of the fast line may be such as to locate the fast line at the exterior of the derrick, as shown in Fig. 1. By thus providing a block which receives the fast line at the exterior of the derrick instead of within the confines of the head of the derrick the rig may be provided with a hoisting mechanism or draw works outside of the base of the derrick, a feature highly desirable in portable derricks.

The mounting of the fast line sheave by which I accomplish the arrangement above referred to is an important feature of my invention. This mounting is accomplished through a hub 30 supported on the shaft l8 and which rotatably supports the fast line sheave eccentric to the shaft l8 and has anchor engagement with a fixed part of the structure such as the shaft mounting I!) which is adjacent the fast line sheave H.

In general the hub is a structure havin an opening 3| passing the reduced end portion 32 of the shaft I8, a rim or periphery 34 which carries the bearing 35 of the fast line sheave I 1, and a reinforcing web 36.

The opening 3|, which receives the shaft portion 32, and the rim 34 of the hub are eccentric to each other so that the fast line sheave I1 is supported eccentric to the shaft l8. In accordance with my invention the fast line sheave is supported so that it is horizontally eccentric to the shaft l8 and this eccentricity is fixed. To accomplish this I anchor the hub 30 against movement or turning. In practice the hub may be anchored in various manners, for instance, in a construction where the shaft I8 is fixed against rotation the hub may be keyed or otherwise fixed directly to the shaft. In my preferred construction, however, I provide an anchor means between an outer or projecting portion of the hub and a fixed part such as the adjoining shaft mounting I 9. In the drawings I have shown an anchor bolt 40 engaged through the outer or projecting portion of the hub 30 and into a lug 4| formed in the said shaft mounting l9.

In practice the hub 30 may be formed or constructed in various manners. However, I prefer to make it a sectional construction, for instance, as I have shown in the drawings, I prefer to form the hub. of sections X and Y which are assembled together to form the hub structure that I have hereinabove described. By providing a sectional hub construction it is practical to provide each section with a radial flange 45 to house the bearing 35 as clearly shown in Fig.

3. As shown in the drawings the hub section X has a flange 46 which engages a flange 41 at the inner face of the bearing mounting I9 while the section Y has a flange 48 .which projects, in a manner to overhang or overlap the hub of the regular sheave adjacent the fast line sheave. Through this construction the series of regular sheaves is confined between the flanges 29 and 48.

When a sectional hub construction is employed the anchor bolt 40 is preferably passed through the two sections as shown in Fig. 3, so that it serves to hold the sections properly assembled.

The shaft mountings l-9 provided by myv invention serve to receive the ends of the shaft [8 and support them fromthe frame members 2 In the preferred form of the invention the mountings I9 are castings designed to rest on the frame members 2| and provided withopenings 50 to receive the ends of the shaft l8. Any suitable means may be employed for fixing the shaft in the mountings 19. In the drawings I have shown threads on the ends of the shaft and lock nuts 60 applied to the ends of the shaft and made fast by suitable locking means 6|. By the construction just described the shaft l8, mounting members 55 and frame l form a solid, rigid structure that effectively carries the sheaves.

The shaft mountings IS are fixed to the frame members 2|. In the particular construction illustrated I provide bolts 8! for securing the mountings 9 to the flanges of the frame members 2|,

It is, of course, desirable in practice to provide a housing over the sheaves and to this end I may form a housing flange or shield lfl-on each of the shaft mountings l9 and may provide a curved guard or shield H which extends between the fianges it and over the several sheaves. Since the fast line sheave is larger than the regular sheaves 2i and projects beyond them the shield H is provided with a laterally projecting portion 72 to house the sheave Il.

It is to be understood, of course, that the construction provided by the invention is provided with means for lubricating the several bearings and that the several sheaves are proportioned and related so that the lines which depend therefrom are properly located to cooperate with the traveling block 25. It is to be noted that by my construction the sheaves are practically all uniformly spaced apart sidewise. The regular sheaves l6 are uniformly spaced apart and through the construction that I have provided the fast line sheave l! is located so close to the adjacent regular sheave that the variation in spacing is negligible. It is also to be noted that the eccentricity of the fast line sheave I1 is related to the size of that sheave and to the regular sheaves so that the line which depends from the fast line sheave i! within the derrick I0 is in the plane of the group A of depending lines shown in Fig. 1.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

1. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft carried by the frame, a series of sheaves supported by the shaft so that the lines depending therefrom are within the derrick, a, fast lin sheave, and means supporting the fast line sheave on the shaft to rotate on an axis offset from that of the series of sheaves with a part projecting horizontally from the head of the derrick.

2. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft carried by the frame, a series of sheaves supported by the shaft so that the lines depending therefrom are within the derrick, a fast line sheave considerably larger in diameter than the other sheaves, and means supporting the fast line sheave on the shaft to rotate on an axis offset from that of the series of sheaves with a part projecting horizontally from the head of the derrick.

3. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft carried by the frame, a, series of sheaves supported by the shaft so that the lines depending therefrom are within the derrick and in two groups disposed to be received by a travelling block, a, fast line sheave, and means supporting the fast line sheave on the shaft with one line depending from it in one of said groups and the other line depending from it outside of the derrick.

4. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft carried by the frame, a series of sheaves supported by the shaft so that the lines depending therefrom are within the derrick and in two groups disposed to be received by a traveling block, and a fast sheave substantially larger in diameter than the other sheaves, and means supported by the shaft and carrying the fast line sheave with one line depending from it in one of said groups and the other line depending from it outside of the derrick.

5. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft carried by the frame, a series of sheaves supported by the shaft concentric thereto so that the lines depending therefrom are within the derrick, a fast line sheave, and

' means supporting the fast line sheave on the shaft eccentric thereto to receive the fast line at the exterior of the derrick.

6. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft supported horizontally by the frame, a series of sheaves supported by the shaft to rotate concentric therewith, an eccentric hub supported by the shaft, and a sheave rotatably supported on the hub.

'7. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft supported horizontally by the frame, a series of sheaves supported by the shaft to rotate concentric therewith, an eccentric hub supported by the shaft, means holding the hub in fixed position, and a sheave rotatably supported on the hub.

8. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft supported horizontally by the frame, a series of sheaves supported by the shaft to rotate concentric therewith, an eccentric hub supported by the shaft, and a sheave rotatably supported on the hub, the hub being formed of two independent sections.

9. A crown block for mounting on the head of a derrick including, a rigid structure embodying a frame and shaft mountings carried by the frame, a shaft carried by the mountings, a series of sheaves mounted on the shaft to rotate concentric therewith, a hub carried by the shaft with its rim eccentric thereto, means anchoring the hub to the said structure in a horizontally eccentric position, and a sheave rotatable on the hub.

10. A crown block for mounting on the head of a derrick including, a rigid structure embodying a frame and shaft mountings carried by the frame, a shaft carried by the mountings, a series of sheaves mounted on the shaft to rotate concentric therewith, a sectional hub carried by the shaft with its rim eccentric thereto, means holding the hub sections together and anchoring the hub to the said structure in a horizontally eccentric position, and a sheave rotatable on the hub.

11. A crown block for mounting on the head of a derrick including, a rigid structure embodying a frame and shaft mountings carried by the frame, a shaft carried by the mountings, a series of sheaves mounted on the shaft to rotate concentric therewith, a sectional hub carried by the shaft with its rim eccentric thereto, a single member holding the hub sections together and anchoring the hub to the said structure in a horizontallyeccentric position, and a sheave rotatable on the hub.

'12. A crown block for mounting on the head of a derrick including, a frame to rest on the derrick, a shaft supported horizontally by the frame, a series of sheaves supported by the shaft to rotate concentric therewith, an eccentric hub supported by the shaft in' position to hold the said series of sheaves against axial displacement on the shaft, and a sheave rotatably supported on the hub.

13. A crown block for mounting on the head of 14. A crown block including, a frame, shaft,

mountings held on the frame, a shaft fixed in' the shaft mountings and having a reduced portion at one end, a series of like sheaves mounted on the shaft in side by side relation and to rotate concentric therewith, an eccentric hub mounted on the reduced portion of the shaft, a sheave rotatably mounted on the hub, the hub being sectional and having a part on each section preventing axial displacement of said sheave, and a single bolt holding the hub sections together and engaging one of the shaft mountings to hold the hub so it supports said sheave horizontally offset relative to said shaft.

15. A crown block including, a frame, shaft mountings held on the frame, a shaft fixed in the shaft mountings and having a reduced portion at one end, a series of like sheaves mounted on the shaft in side by side relation and to rotate concentric therewith, an eccentric hub mounted on the reduced portion of the shaft, a sheave rotatably mounted on the hub, the hub being sectional and having a part on each section preventing axial displacement of said sheave, and a single bolt holding the hub sections together and engaging one of the shaft mountings to hold the hub so it supports said sheave horizontally offset relative to said shaft, the hub operating to support said sheave adjacent the series of sheaves and also operating to hold said series of sheaves against axial displacement.

' GLENN D. JOHNSON.

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