US2233648A - Crown block construction - Google Patents

Description

March 4, 1941. w B SQUNlTZA 2,233,648

CROWN BLOCK CONSTRUCTI O N.

ATTRNE Y March 4, 1941- w. B. soUNl'rzA 2,233.648

CROWN BLOCK CONSTRUCTION Filed Dec. 18, 1937 5 Sheets-Sheet 2 March 4, 1941. w. B. souNlTzA CROWN BLOCK CONSTRUCT I ON Filed Deo. 18. 1937 3 Sheets-Sheet 5 wv 6 w A mi MLM W I N VEN ITOR Patented Mar. 4, 1941 -U N'I'TED STATES PATENT OFFICE CROWN BLOCK CONSTRUCTION Application December 18, 1937, Serial No. 180,558

4 Claims.

My invention relates to crown blocks, such as are commonly installed at the upper ends of derricks on oil wells; and my invention particularly relates to a unique bearing assembly which may constitute a part of such a crown block construction.

'Ihe crown block commonly employed at the upper end of oil well derricks consists of a plural- 1 ity of beams which support bearing assemblies in which shafts are rotatable. Mounted on the shafts are sheaves over which the cable, which extends downwardly to the travelling block, is wound. It is an object of my invention to provide i.) a crown block which incorporates in the bearing assembly self-aligning kbearings so that bearing alignment may be obtained with no diiiiculty upon original installation, and so that any changes in position which may occur during the use of the crown block may be automatically compensated for-.so that bearingalignment will be maintained throughout the period of use of the crown block.

It is a further object of my invention to provide a unique bearing assembly for a crown which is of simple construction consisting essentially of a cast box and a bushing resting on suitable supporting surfaces in the box and without means of attachment thereto, and in which there is provided means engageable by the bushing upon up- 30 ward movement thereof in order that if, upon raising the crown block shaft from the box, the bushing adheres thereto, it will be disengaged from the shaft and retained in the box, with the result that there will be no danger of the bushing being inadvertently removed from the box and possibly falling downward through the derrick and injuring a workman.

It is a further object of my invention to provide a unique bearing assembly for use as a part of the crown block construction in which the parts are designed so that there is but a minimum of machining'. In this way the bearing assembly may be provided at a minimum of cost and yet satisfactorily perform all of the duties necessary 415 for a satisfactory operation. In the preferred form of my invention I provide a box, the lower surface of which is machined so that it may rest on a supporting wall, and within the box I provide ajournal which includes journal elements '0' having machined surfaces. Cooperating with the box'is a bushing having a bearing consisting of elements having machined surfaces for cooperation with the machined surfaces of the journal elements `and also having a shaft supporting wall 55 which i-swmachined and which lsupports the crown block shaft. If desired, in order to enclose the upper part of the box, a cover may be provided, and this is done in the preferred form of my invention.

It is a further object of my invention to provide 5 a bearing assembly having a unique oiling means for delivering oil to the shaft supporting portion of the bushing.

It is a still further object of my invention to provide a crown block construction in which the assembly of the bearing unit, shaft, and sheaves may be readily secured in position on the supporting means and may be readily released and adjusted into any desired position along the beam.

It is also anv object of my invention to provide a combination of this character in which when the assembly is released it can be slid along the supporting beams but cannot be raised from position thereon.

It is a further object of my invention to provide a bearing assembly having a simple yet effective means for clamping the box of the assembly in any position along the supporting beam.

Other objects and advantages of my invention will be pointed out in the course of the following detailed description of a preferred form of my invention.

`Referring to the drawings:

Fig. lis a plan View of a portion of a crown blockv incorporating the features of my invention.

Fig. 2 is a section through one of the bearing and sheave assemblies and is taken on the line 2-2 of Fig. 1. 35

Fig. 3 is a cross-section through a bearing assembly of my invention and is taken as indicated by the line 3--3 of Fig. 1.

Fig. 4 is a sectional view taken as indicated by the line 4-4 of Fig. 3.

Fig. 5 is a section through the securing means of my invention and is taken as indicated by the line 5-5 of Fig. 3.

Fig. 6 is a plan view of the box which incorporates a part of my invention.

Fig. 7 is a perspective view showing the bushing which constitutes one of the elements of my invention.

Referring `to the drawings in detail, and particularly Figs. 1 and 2, the numeral Il represents 50 I-beams which constitute supporting beams of my invention and are adapted to be supported at the upper end of the derrick. It will be noted that la plurality of beams Il extending parallel to `each-other is provided, and that supported on the beams vI I aresheave assemblies I2, each of which is independently adjustable so that sheaves I4 thereof may be suitably positioned at the upper end of the derrick. As shown best in Figs. 1 and 2, each of the sheave assemblies I2 consists of a pair of bearing assemblies or bearing units I5, each of which is supported on a beam I I, a shaft I6, andthe sheave I4 which is mounted on the shaft. As illustrated in the various views, the bearing assembly includes a box I8 which has a I lower machined surface I9 adapted to rest on an upper supporting wall 26 of the supporting beam II. This box I8 of each bearing assembly is shaped to provide a lubricant chamber 2I which may be provided with lubricant, as indicated at 22. Within the chamber 2| there is a journal which'is preferably provided in the form of a pair of spaced journal elements 23 which project upwardly from a bottom wall 24 of the box I8. These journal elements provide spherical journal walls 26 which cooperate to provide a spherical journal, and these walls 2.6 are generated around the same center.

Adapted to cooperate with the box I8 is a bushing 30 which includes a semi-cylindrical shaft supporting wall 3I having an inner machined surface 32 adapted to receive the end of the shaft I6. At the outer ends of the bushings 30 are end walls, such as illustrated at 33 in Fig. 4,

having machined surfaces 34 which engage end walls 35 of the shaft I6 to prevent axial movement thereof. i

Each bushing 38 is provided with a spherical bearing adapted to seat in the spherical journal and is provided in the form of a pair of longitudinally spaced bearing elements 31 which project downwardly from the wall 3l, and which have machined spherical walls 38 which are generated around a point and on a radius the same as that around which the journal walls 26 are generated. As shown in Figs. 3 and 4, the walls 26 and 38 coengage each other, and this constitutes the wall supporting means for the bushing 36 in the box I8. This arrangement permits a universal movement of the bushing 30 and enables alignment of the bearings with the shafts supported thereby.

It will be noted that the bushing 30 merely rests in the box I8 and there is no securing means for securing the same in place. In view of the fact that the end of the shaft is supported by the bushing 30 and the wall 32 is supplied with lubricant, there may be sufficientI cohesion between the parts so that when the shaft is raised upward relative to the box the bushing will be raised therewith, and when moved free of the box the cohesion-may decrease in strength or the shaft and sheave assemblies may be tilted into such position that the bushing will be released therefrom and fall. Since the assembly is used at the top of the derrick, it mayfall to the floor of the derrick and not only cause breakage of the part but may cause serious injury to any workman on the derrick floor.

One of the important features of my invention is a very simple yet effective means of preventing removal of the bushing from the box upon raising the shaft upwardly therefrom. This important object of my invention is lquite simply accomplished by providing the upwardly extending wall 48 with an inwardly projecting engageable means in the form of a lug 4I. This lug 4I extends inwardly so as to be engageable by the bushing 30 if herein I prefer to position the lug 4I directly above the end wall 33 but spaced therefrom so I that normally there is no engagement between the lug 4I and any part of the bushing 30. This is desirable in order to prevent free movement of the bushing in the box in order to permit alignment of the parts. It will be seen, however, that upon upward movement of the bushing the wall 33 engages the lug 4I and thus prevents further upward movement thereof and separates the same from the end of the shaft I6. 'I'his construction, however, after the shaft I6 has been removed does not prevent removal of the bushing 30 by the workman, which may be done by moving the bushing rightwardly (with reference to Fig. 4) so that the lug 4I will not be engaged.

It will be noted that between the bearing elements 31 there is provided a central channel 45 which extends through the body of lubricant 22. For the purpose of lubricating the end of the shaft I6 and the supporting wall 3| there is provided an oil distributing means in the form of an endless belt 46 which extends around the upper part of the shaft and downwardly on opposite sides of the Wall 3| and through the channel 45. When the shaft I6 is rotated the endless belt 46 is moved and this carries oil upwardly onto the shaft and between the coengaging surfaces of the shaft and wall 3|.

In order to close the upper part of the box I8 I provide a suitable cover 46 rwhich is pivoted to the box, as indicated at 50, and is releasably held in closed position by a suitable latch means 5I. Upon releasing the latch means 5I the cover may be swung into an open position which gives free access to the interior of the box I8.

For the purpose of adjustably securing the boxes I8 to the supporting beams II `I provide a construction which will now be described. VExtending outwardly from opposite sides of thebox I8 are box flanges 55 which, as shown in Fig. 5, rest directly above the edge portions of beam flanges 56. Each pair of box and beam flanges 56, there being two on each side, constitute -a. wedge shaped projection due to the fact that either or both of the outer faces 51 and 58 are inclined and thus provide a projection which converges outwardly and is therefore of wedge shape. Adapted to cooperate with each projection is a` U- shaped clamp member or block 60 having anV outer wall 6I and inwardly projecting walls 62 having inner surfaces 63 adapted to engage the outer faces 51 and 58 of the projection cooperating therewith. As shown in Fig. 5, the clamps are positioned at each side of the beam with the surfaces 63 in coengagement with the surfaces 51 and 58, and it will further be seen that upon forcing the clamps 68 inwardly the boxes are securely pressed and clamped downward against the supporting surface 28 of the supporting beam II and thus rigidly secured in any given position along the beam. For the purpose of effecting this clamping action, I provide a bolt means in the form of a carriage bolt 65 which extends laterally through transverse channels 66 which are formed in the bottom wall 24 of the box I8 and extend through the box flanges 55, as shown best in Fig. 5. The walls 6I of the'clamps 66 have openings 61 through which the bolt means extends, there being a head 68 on one end of the carriage bolt 65 and a nut 69 on the other end thereof which may be tightened in order to force the clamps 60 together.

It is a feature of the invention that this clamp construction be of simple yet effective design and that upon loosening the carriage bolt the clamps release their clamping force and permit the box to be adjusted longitudinally of the supporting beam I I. When the `clamp means is released the walls 62 still extend inwardly in a surrounding position around the adjacent flanges 55 and 56, and the boxes cannot be raised or removed from the supporting beam Il by an upward or sideward movement. This provides a measure of protection and prevents the parts from being accidentally dropped from the top of the derrick.

In the foregoing description I have considered a preferred form of my invention. It should be understood, however, that the principle of my invention may be employed in other forms, and that I do not wish to be limited to the details of construction illustrated herein but wish my invention to -be broadly construed in accordance with the appended claims.

I claim as my invention:

1. In a crown block assembly of the character described, the combination of a sheave member having axial shaft elements projecting therefrom; and bearing means to receive said shaft elements, said bearing means each comprising a box having an upwardly faced chamber with a side opening to receive one of said shaft elements, there being in said chamber a support to adjustably receive a bearing bushing, and a bearing bushing in said chamber of said box, said lbearing bushing having means on the lower part thereof for cooperative engagement with said support and an essentially semicylindrical wall forming an upwardly faced pocket to receive the shaft element, there being an end wall at the end of said essentially semicylindrical wall to engage the end of the shaft element so as to limit end movement thereof.

2. In a bearing assembly adapted for use as a part of a crown block, the combination of: a box having a spherical journal consisting of two spaced journal elements; a bushing including an essentially semicylindrical shaft supporting wall for supporting a shaft of the crown block, and

having a spherical bearing adapted to seat on said spherical journal, which includes a pair of bearing elements each being adapted to engage and cooperate with one of said journal elements; a detachable cover element passing over said shaft and limiting its upward movement relative to said box; and engageable means positioned on said .box so as to be engaged by said bushing should the same be raised upward relative to said box with said shaft after removal of said cover element.

3. In a bearing assembly for use as part of a crown block, the combination of z a box having an upwardly faced pocket defined by a bottom wall and a side wall; a bearing bushing seated in said pocket, said bushing being characterized by having a substantially cylindrical shaft supporting wall; and a lug projecting from said side wall of said box in a position above a part of said bushing, to -be engaged by said bushing when the same is raised from its seated position in said pocket and to prevent said bushing from being raised from said pocket as said shaft is raised from its position of operation relative to said box.

4. In a crown block bearing assembly, the combination of: a box having an upwardly faced pocket defined by bottom and side walls; a bearing bushing adjustably seated in said pocket, said bushing being characterized by having a substantially semi-circumferential shaft supporting wall; and means to-restrain said bushing from being raised out of said pocket when said

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