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Publication numberUS2681794 A
Publication typeGrant
Publication dateJun 22, 1954
Filing dateJun 13, 1950
Priority dateJun 13, 1950
Publication numberUS 2681794 A, US 2681794A, US-A-2681794, US2681794 A, US2681794A
InventorsJohnson Glenn D
Original AssigneeBaash Ross Tool Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Traveling block and connector
US 2681794 A
Abstract  available in
Images(3)
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Claims  available in
Description  (OCR text may contain errors)

G. D. JOHNSON TRAVELING BLOCK AND CONNECTOR June 22, 1954 :s sheets-sheet 1 Filed June 13, 1950 TRAVELING BLOCK AND CONNECTOR Filed June l5, 1950 Sheets-Sheet 2 E 1 y 46 47 ijg 35 17 je l' I H lll l 4e 45 4a 9J.. "Qz "152 ...L9

4- 65 44 10 L 4f-'Z3 55 42 n 5f 74 5J-. 731.5

as 7 90 -l a5 a4 @.9 a;

\ INVENTOR.

G25/wv z'o/-f/vswf, 4 By June 22, 1954 G. D. JoHNsoN 2,681,794 TRAVELING BLOCK AND CONNECTOR Filed June 13, 1950 3 Sheets-Sheet 3 ll l INVENTOR. LEN/v .0. ZfOHA/SOM BY 60152 .619 J6 56a 57 60 5g Mur/ rToe/VEY.

Patented June 22, 1954 'TRAVEIING BLOCK AND CONNECTOR Glenn D. Johnson, Compton, Calif., assignor to Baash-Ross Tool Company, Los Angeles, Calif.,

a company of California Application June 13, 1950, Serial No. 167,836

(Cl. 25d- 192) 11 Claims. l

The present invention relates to elevator devices, and more particularly to traveling blocks 'and' connectors especially useful on well drilling or production rigs.

An `object of the 4present invention is to provide a traveling `block and connector, or traveling block and hook assembly, that has a comparativelyshort `over-all vertical length for the load carrying capacity of the assembly, thereby permitting use of the assembly, with facility, on short derricks and Adrilling masts.

Affurther object of `the invention is to provide a telescopic arrangement of a traveling block and 'associated connector unit, thereby materially lshortening the over-al1 length of the assembly.

Another object of the invention is to provide a combined traveling block and swivel, in which the swivel is telescoped or piloted into the block housing, for the purpose of materially shortening the over-al1 length of the assembly.

Yet another object of the invention is to greatly increase the .load carrying capacity of a traveling block having a cast frame or outer housing. In a more limited sense, this objective contemplates the relieving of the cast housing of substantially al1 of the thrust or load being transmitted between the various parts of the traveling block and an associated connector unit, which unit may have elevator ears for supporting elevator links, or which may include a hook, or both.

A further object of the invention is to provide a traveling. block assembly possessing maximum compactness .and strength, and which is streamlined by avoiding or minimizing the presence of projecting parts and .sharp edges `or corners.

Still a .further object of the invention is to Yprovide afcombined traveling bloc-k; and associated connector unit, in which the latter Vconstitutes a closure for .the lower end of the block frame or housing.

Another -object` of the invention is to provide for the addition of weight, if desired, to a travelying block assembly, without aiiecting or altering its external dimensions.

Yet another object of the invention is .to provide a guard arrangement in a traveling block for the sheaves and line, which enables the line to be threaded around the sheaves without necessitatingremoval ofthe guard.

A further object of the invention is to provide a combined and compact assembly of a traveling block and connector' unit, in which the latter can abe `easily disconnected from, or assembled to, the traveling block portion of the assembly, and which 2 allows the line to be threaded readily through the block without detaching the connector unit from it.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best dened by the appended claims.

Referring to the drawings:

Figure l is a side elevation of the apparatus;

Fig. 2 is a front elevation of the apparatus;

Fig. 3 is a vertical section through the apparatus, on an enlarged scale, with parts in elevation;

Fig. 4 is a vertical section taken along the line lm-4 on Fig. 3;

Fig. 5 is a cross-section taken along the line 5-5 on Fig. 3;

Fig. 6 is a vertical section taken along the line 6 5 on Fig. 4,;

Fig. 7 is a cross-section taken along the line l-1 on Fig. 3;

Fig. 8 is a top plan view of the lower cowling with the guard plate removed;

Fig. 9 is a cross-section taken along the line 9--9 on Fig. 3; and

Fig. l0 is a vertical section taken along the line lll-I0 on Fig. 3.

As disclosed in the drawings, a traveling block A and connector B, or combined hook and link support, are operatively secured to one another, to be supported from the usual crown block of a suitable derrick or drilling mast by a wire or other flexible line C. For the purpose of shortening the over-all vertical length of the assembly, the connector unit B is telescoped into the block portion A of the device. The arrangement is such that the connector unit actually forms a lower closure for the block portion.

A plurality of sheaves Ill is arranged in side by side relation within the upper frame, shell or casing Il of the block. This shell or casing is of streamlined shape and is usually made Aof cast steel. It is desired to avoid imposing any of the load carried by the wire line on the cast steel housing or shell Il, since such castings are of lesser strength than rolled or forged structural elements. Instead, the load is transmitted between the sheaves III and the connector unit B through a pair of opposed side plates I2, I3, that may be made of rolled steel, the plates iitting Within recesses I4 in the inner side walls l5, I5 of the upper frame II. The plates I2, I3 are preferably secured to these side Walls of the frame by welding material Il.

A center pin I8 extends between the plates I2, I3. One end of the pin is received within a two-piece collar i9 fitting within a hole 20 in one side plate I2, and having an inwardly directed flange 2l received within a peripheralrpin groove 22. The split or two-part collar i also has an outwardly directed flange 23 engaging the outer surface or the plate I2. This end of the pin and the collar i9 are disposed within a suitable hole 24 in one side wall I5 of the cast frame, the pin I8 preferably terminating inwardly of the external surface of such wall, to avoid a projecting element.

The other end of the center pin extends through a clamp ring 25 disposed in a hole 26 in the other side plate I3. This clamp ring abuts the inner race 2'! of a tapered roller bearing assembly 23, the outer race 29 of which is disposed within a sheave I9. There is one bearing assembly 2S for each of the sheaves, which are arranged in side by side relation, so that all of the bearing assemblies can be secured between .the clamp ring 25 and the center pin collar I9. Such clamping or securing action occurs as the result of tightening a clamp nut 39 on the threaded end of the center pin that bears against the clamp ring 25, the nut being prevented from loosening or unthreading by a suitable lock plate 3| projecting into one of the peripheral notches 32 inthe nut and secured to the side plate I3 by one or more cap screws 33. The threaded end of the pin I8, nut 30, lock plate 3l and cap screws 33 are located in a hole 34 in the frame wall I6, and also do not project beyond the outer surface of this wall, to avoid projecting elements.

The side plates I2, i3 depend from the center pin I8 and disposed within the depending skirt portions or sides l5, I6 of the cast frame I I. The lowermost ends 35 of the front and back portions 35, 31 of the cast frame II terminate substantially in a horizontal plane including the axis oi' the center pin I8. There is thus provided a substantial opening around the bottom of the cast shell II which is closed by the coni nector unit B.

The connector unit includes a lower housing, frame or Cowling 38 having curved outer end walls 3S, 4D, which converge in convex fashion toward each other in a downward and inward direction, their lower ends being integral with a generally cylindrical inner wall 4I extending upwardly from the ends of the outer walls and merging into a central boss 42. The end walls 39, 45 and inner wall 4I, as well as the boss 42, are integral with opposed side walls 43, and also with aligned center ribs 44 extending between the end walls 39, 40, on the one hand, and the inner wall 4I and boss 42, on the other hand. The spaces 45 between the various walls, boss and ribs provide pockets in the lower frame or Cowling 38, which pockets may be placed in communication with each other by providing one or more holes 46 through the ribs 44.

The lower frame or Cowling 33 is designed to fit between the side plates l2, i3 and depending skirts I5, I6 of the upper frame il, and is also arranged to extend around the lower portions of the sheave I9, to complete the enclosure for the latter. Thus, the side walls 43 of the cowling are disposed adjacent the side plates I2, I3 and skirts I5, I5, whereas the outer end walls 39, 49 extend upwardly to bridge the space between the depending skirts I5, IS and engage the iront and back portions 3B, 31 of the upper frame II. In order to insure a proper relationship between the upper and lower housing parts II, 39, the upper portions 451 of the end walls 39, 59 may overlap lips 41 depending from the upper frame.

The side walls 43 of the cowling, its center ribs 44, and the upper end of the central boss 42 are arcuate in shape, conforming to the curvature of the sheaves Ii), but being spaced therefrom by a slight amount. Such spacing is preferably kept to a minimum, in order to minimize the lengthA of the entire assembly. An arcuate guard plate 48 is disposed along the top ends of the side walls 43, center ribs 44 and boss 42, and is suitably welded thereto, in order to prevent interference with the line C as it passes around the sheaves I9. This arcuate guard plate preferably has holes 497therethrough communicating with the Cowling pockets 45, and a central hole 50 for enabling the stationary swivel pin 5I of the connector unit to be appropriately assembled in place.

The lower frame or cowling 38 is firmly attached to the rolled steel side plates I2, I3 by a plurality, such as a pair, of coupling pins 52 extending transversely throughl these side plates I2, I3 and through the central boss 42 on opposite sides of the stationary swivel pin 5I. Each couplingr pin lits snugly through holes 53 in the side plates, and through an aligned hole 54 in the boss. Each coupling pin 52 has a. head 55 located within a hole 55 in the upper frame skirt I5 and bearing against the exterior of the plate i2. The other end of the pin 52 extends into a hole 56a in the other frame skirt I5, and is threaded for reception of a suitable nut 5'I, which is tightened against the exterior of the opposite plate I3. Loosening of this nut 5'I may be prevented by a suitable locking device, which may take the form of a plate 58 extending into one of the notches 59 in the periphery of the nut, the plate 58 itself being secured to the frame skirt l5 by a plurality of cap screws 6U.

It is apparent from the foregoing description that the lower cowling 38 forms a closure for the upper frame or shell I l, and that such lower cowling is rmly and rigidly attached to the side plates I2, I3 by the coupling pins 52, the side plates, in turn, carrying the center pin I8 on which the sheaves I9 are rotatably mounted. In order to complete the streamlining of the unit, lobes 6I may project outwardly from the` sides 43 of the Cowling, such lobes extending from the lower ends of these sides, with their outer surfaces 62 diverging and merging smoothly into the external surfaces of the upper frame skirts I5, I6. The lobes 6I terminate immediately below the lower ends of the skirts and the side plates, as clearly illustrated in Figs. 2 and 4.

The connector unit B disclosed in the drawings includes the aforementioned stationary swivel pin 5I, which extends upwardly through the inner wall 4I of the lower frame 38, and through a central vertical bore G3 in the central boss 42. The upper end of the vertical pin 5i is carried by the central boss through the agency of a two' part, or split, lock collar 54, which rests upon a shoulder 55 formed by an upper enlargement 83a of the bore 63. The collar has an inwardly directed flange 56 tting within a peripheral groove 6l in the pin 5I, in order to transmit the 5 downward load onh the pin 51| throughstheicollar 64 totheboss shoulder-.65.

The pin 5| d'epend's'fronrthe boss and terminates in a head 68 `a` substantial distance below the lower end ofthe inner `wall 4| and outer end walls 35, 4U of the cowlingt.` This pin forms the stationary element` oi"` a swivel,` the rotatable or` turning element of which, may be formed as a hook 6g. This latter part includes a lower hook housing l extendingrupwardly around the pin iV and threaded onto anupper hook housing 1| projecting intozthe inner wal-l `4| of the cowling.` This'iupper housing terminates in a thrust head 1,2` that isengiageable, with the lower end ofthe central boss `42;. Suchfem gagement is effected, under comparativelylight or substantially zero load conditions imposedon the hook, by outer and inner helical springs 13, 14 whoseupper ends bear upon the thrust head 12, and Whose lower ends bear upon-a` thrust plate 15 resting against a suitable thrust bearing' 16, which is, in turn, supported upon lthe stationary swivel pin head 68. It is` apparent .that the upper and lower hook housings 10, 1| may turn relative to the stationary pin 5| with substantial freedom, in View of thellower thrust bearing 16.

Theinner and outer springcarrangement 14, 13 presents a relative short or compact unit for holding the hookhousing 1U, 1| `in an upward position under certain conditions. As load is imposed upon the hook 69, the springs 13., 14 are compressed ,until `the thrust head. 121 engages the upper end of a stop and' thrust sleeve 11 disposed around theV swivel pin 5| and resting uponthe thrust-plate 15. Usually, theasprings exert only sullicient force to ai'din the,` elevation of a stand of pipe, as it is being unscrewed from a lower section of pipe supported inthe rotary tableiof the rig. Greaterloads result a downward pulling of the hook housing ;,1I'` and en*-A gagement of the thrust head 12` with the thrust sleeve 11, for the purpose of' transmitting the load solidly through the thrust plate and thrust bearing 16 tothe pin. head 68,r where the load passes through thepin 5| andfdivided lock collar 64 to the boss 42- of the cowling. From this boss, the load is transmitted` through the coupling pins 52 to the side plates IZ, I3, and from these latter members through the `center pin I8 to the sheaves I3 and- `line C-..

The lower swivel unit illustrated` in' the drawe ings is designed to support both elevator `links (not shown) and a swivel bail (not shown)- simultaneously. The elevator links can be i carried by ears 1t projecting outwardly fromthe sides of the lower hook housing 1t, these links being prevented from inadvertent removal by link gates 19. The lower ends of the gates arepivotally mounted on pins BD carried bythe ears 1.8; and the upper ends` are secured bysuitablefscrews 8| to lugs. 82 projecting from the lower hook housing.

The swivel bail (not shown) is carriedi bythe hook portion 83 of the unit, whichtdepends; from the lower housing 1i),` and has a latch bodyd pivoted on a hingeI pin Brsecured to. thev hook, the body extending across theI hook opening.. This body is prevented fromswingingwoutwardly by a suitable latch 36 mounted on aI latch pin 81, and adapted to engage a, lock plate or insert 88 welded to the hook body 83. This latchr S6 is urged towards its locking positionby aspring 89 tting within a socket 90, in the latch body and pressing against `aplunger 9| which; engages thelatch 86.

The arcuate guard' plate 48 notonly protects the.l sheaves I0 and theline C from interference withv the connector'unit- B therebelow, butyit 'also serves as a gui'deff'or threading the li-nethrough the openings 92 in the upper frame andl around the sheaves, thereby obviating the need for dis-- mantling the apparatus; However, ifsuch threading is not to be performed without dismantling the connector unit` B from the upper housing ll, it is a simple matter to remove the two coupling pins 52 and lower the cowling 3B, with all ofthe parts attached thereto, `from the upper` housing, which then exposes the underside of the sheaves Ill-and enables the line C to be threaded appro.-

' priately around the sheaves.

The connector unit B; in elect, is telescoped or piloted upwardly" within the block frame: lil to` a pointv immediately adjacent the sheaves l0, which enables-the ent-ire assembly to have-a much lesser over-all length than was heretofore possible. Such decrease in over-all length is further enhanced by the upward telescoping or piloting of the swivel into the-cowling or lower framel 38; and also by the piloting of the hookhousing 10, 1l into the lower frame 38. Despite such piloting and consequent compact arrangement; the hook is still capable of swiveling freely through 360 degrees, and the springs 13, 14- associated therewith are still capable of facilitating u-nscrewing of a stand of pipe, orother objects, from the pipe supported in; theA rotary table.

All loadsY are transmitted through the'i side plates |2; I3 ofthe device, and not through the oast'steell upper frame or-shell I. As an result, the outer shell `orl housing of the device Ca-ncbo fully streamlined, so` as to avoidl projections. that may'tend to hang up or-interfere withotherparts usually present in and` around rigs. While the lowencowling 38 is,` a casting; it possessesfsub-` stantial strength, since the loadis transmitted through `the comparatively thick boss 42 to the coupling `pins 52, that are, in turn, supported by thefrolledsteel sideplates l2, |3. The sidewalls 43,-V center ribs 44 andiouter end walls 39, 40 of the cowling or lower housing- 38 are not required to` carry any portion of the load, and readily adapt themselvesto -a casting operation to produce astreamlined form.

The-diminished over-all lengthofthetravelingblock and'connector unit` combination is ac-` companied by a decrease in weight. At times, it may bedesirable to have the entireAv assemblage weighmore,V and this is` readily accomplished in the-present instance by disposing weighting material in the pockets. 45* providedV in the' lower housingj. As an example, leadcan be poured through the guard plate holes 49. into the pockets 45,the'volume of thepocketsbeing quite exten sive and capable of receiving a substantial weight of lead. The lead willbe retained in place, since `itiwill flow, when in a molten1 state, through the rib. holes 46, from one-pocket to the. adjacent pocket, thereby1 integrating and locking thecontents ofthe pockets toone another.

In the manner just described, additional weight may he added to the.V block` and connector unit assembly without interfering4 with. the opera,v tionlofl any of its parts and without increasing. thef'size4 of the devicein any particular.

The inventor claims:

1. In apparatus` ofthe characterv described; anupper; housing; a supporting member within and. carried `by said housing; sheaves rotatable onA saidsupporting member; a lower housingsecured to said upperhousing and closing the lower portiono'i' said upper housing, said lower housing having one or more pockets thereinadapted to contain weighting material; load supporting means carried by and depending from said lower housing; generally arcuate guide means on said vlower housing conforming to and cl-osely adjacent the lower peripheral portions of said sheaves, said guide means having one or more openings therein communicating with said one 'or more pockets.

2. In apparatus of the character described: an upper housing; a supporting member within and carried by said housing; sheaves rotatable on said supporting member; a lower housing secured to said upper housing and closing the lower portion of said upper housing, said lower housing having one or more pockets therein adapted to contain weighting material; load supporting means carried by and depending from said lower housing; and means providing access to said 'one or more pockets. 3. In apparatus of the character described: a housing; a supporting member within and carried by said housing; sheaves rotatable on said supporting member; load supporting means carried by and depending from said housing, said housing having one or more pockets therein adaptedv to contain weighting material; and means providing access to said one or more pockets for the introduction `of the weighting material therewithin.

4. In apparatus of the character described: an upper cast housing having curved front and back walls and side walls depending substantially below said front and back walls; opposed side plates disposed within and secured to said side walls; a pin extending between and carried by said plates; sheaves rotatable on said pin; a lower housing extending upwardly between the side walls of said upper housing and having end walls termihating adjacent the lower ends of said front and back walls, said lower housing having one or more pockets therein adapted to contain weighting material; generally arcuate guide means on said lower housing conforming to and closely adjacent the lower peripheral portions of said sheaves, said guide means having one or more openings therein communicating with said one or more pockets; coupling pins securing said lower housing to said plates; a stationary pin extending upwardly into said lower housing between said coupling pins; means supporting said stationary pin by said lower housing; and load supporting means extending upwardly into said lower housing, said load supporting means being rotatably carried by said stationary pin.

5. In apparatus of the character described: an upper cast housing having curved front and back wallsand side walls depending substantially below said front and back walls; opposed side plates disposed within and secured to said side walls; a pin extending between and carried by said plates; sheaves rotatable on said pin; a lower housing extending upwardly between the side walls of said upper housing and having end walls terminating adjacent the lower ends of said front and back walls, said lower housing having one or more pockets therein adapted to contain weighting material; generally arcuate guide means on said lower housing conforming to and closely adjacent the lower peripheral portions of said sheaves, said guide means having one or more openings therein communicating with said one or more pockets; coupling pins securing said lower housing to said plates; a stationary pin extending upwardly into said lower housing between said coupling pins", Ysaid 'stationary pin having a head; a split collar engaging said stationary pin and lower housing to support said stationary pin from said lower housing; a load supporting enclosure extending upwardly into said lower housing and encompass# ing said stationary pin; and rotatable means for transmitting the load on said enclosure to said head,

6. In apparatus oi the character described: a one-piece upper frame having curved front and back walls and side walls depending substantially below said front and back walls; a pin extending between and carried by said side walls; sheaves rotatable on said pin; a one-piece lower frame extending upwardly between said side walls and having end walls terminating adjacent the lower ends of said front and back walls and portions between said end walls terminating adjacent the lower ends of said side walls; the upper portion of said lower frame having generally arcuate guide means thereon conforming to and lying closely adjacent the periphery of said sheaves; means rigidly and immovably securing said lower frame to said upper frame; a stationary swivel pin carried by and depending from said lower frame; a swivel member surrounding and movable longitudinally of said swivel pin; and spring means surrounding said swivel pin and bearing upon a lower portion of said swivel pin and an upper portion of said swivel member.

'7. In apparatus of the character described: a one-piece upper frame having curved front and back walls and sidewalls depending substantially below said front and back walls; a pin extending between and carried by said side walls; sheaves rotatable on said pin; a one-piece lower frame extending upwardly between said side walls and having end walls terminating adjacent the lower ends of said front and back walls and portions between said end walls terminating adjacent the lower ends of said side walls; the upper portion of said lower frame having generally arcuate guide means thereon conforming to and lying cl'osely adjacent the periphery of said sheaves; means rigidly and immovably securing said lower frame to said upper frame; a stationary swivel pin carried by and depending from said lower frame; a swivel member surrounding said swivel pin and extending upwardly into said lower frame; and spring means surrounding said swivel pin and bearing upon a lower portion of said; swivel pin and an upper portion of said swivel member.

8. In apparatus of the character described: a one-piece upper frame having curved front and back walls and side walls depending substantially below said front and back walls; a pin extending between and carried by said side walls; sheaves rotatable on said pin; a one-piece lower frame extending upwardly between said sidewalls and having end walls terminating adjacent the lower ends of said front and back walls and portions between said end walls terminating adjacent the lower ends of said side walls; means extending through said side walls and upwardly extending portion of said lower frame in a direction parallel to the axis of said pin for securing said lower frame to said upper frame; and load supporting connector device closing the lower portion of said housing; means extending through said side members and connector device parallel to the axis of said supporting member for securing said housing and connector device together; the upper portion of said device being generally arcuate to conform to the periphery of said sheaves and lying closely adjacent said sheaves along the lower portion of said sheaves to provide a guide facilitating threading of a flexible line around said sheaves.

10. In apparatus of the character described: a one-piece upper frame having curved front and back walls and side walls depending substantially below said front and back walls; a pin extending between and carried by said side walls; sheaves rotatable on said pin; a one-piece lower frame extending upwardly between said side walls and having end walls terminating adjacent the lower ends of said front and back walls and portions between said end walls terminating adjacent the lower ends of said side walls; means extending parallel to said pin and through said side walls and upwardly extending portion of said frame for rigidly and immovably securing said lower frame to said upper frame; a stationary swivel pin disposed within, carried by and depending from said lower frame; and a swivel member extending upwardly within said lower frame and surrounding and movable longitudinally of said swivel pin.

1l. In apparatus of the character described: an upper housing; a supporting member within and carried by said housing; sheaves rotatable on said supporting member; a lower housing extending upwardly within and closing the lower portion of said upper housing; means extending through said upper housing and the upwardly extending portion of said lower housing in a direction parallel to the axis of said sheaves for securing said housings together; load supporting means carried by and depending from said lower housing; and generally arcuate guide means on said lower housing conforming to and closely adjacent the lower peripheral portions of said sheaves.

References cited in the me of this patent UNITED STATES PATENTS Number Name Date 1,713,586 Wright May 21, 1929 2,282,633 Young May 12, 1942 2,502,570 Johnson Apr. 4, 1950 2,513,990 Bennett July 4, 1950 2,536,417 Black Jan. 2, 1951 2,556,165 Christensen June 12, 1951

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1713586 *Jul 20, 1927May 21, 1929Oklahoma Iron WorksTackle block
US2282633 *Feb 7, 1940May 12, 1942Nat Supply CoHoisting block
US2502570 *Aug 20, 1945Apr 4, 1950Johnson Glenn DTraveling block
US2513990 *Aug 25, 1947Jul 4, 1950Internat Derrick & Equipment CSpring loaded hydraulic adapter
US2536417 *May 12, 1947Jan 2, 1951Black Lester CTraveling sheave block
US2556165 *Jul 14, 1947Jun 12, 1951Byron C ChristensenCombination traveling block and swivel connector
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2980400 *Feb 5, 1957Apr 18, 1961Armco Steel CorpHook-block assembly
US3278163 *Oct 7, 1964Oct 11, 1966Dresser IndHook assembly
US4498698 *Apr 18, 1983Feb 12, 1985Varco International, Inc.Drill rig hook
US5476247 *Oct 18, 1993Dec 19, 1995Msi Crane & Equipment Co.Load block
EP0124467A1 *Mar 16, 1984Nov 7, 1984Varco International, Inc.Drill rig hook
WO1995011188A1 *Oct 14, 1994Apr 27, 1995Msi Crane & Equipment CoLoad block
Classifications
U.S. Classification254/401
International ClassificationE21B19/04, E21B19/00
Cooperative ClassificationE21B19/04
European ClassificationE21B19/04