Drilling hook

May 16, 1939.

Η. E. GRAU ET AL

2,158,232

DRILLING HOOK

Filed Dec. 6, 1937 3 Sheets-Sheet 1

<img file="US2158232A_D0001.tif" />

<img file="US2158232A_D0002.tif" />

May 16, 1939.

Η. E. GRAU ET AL

2,158,232 drilling hook

Filed Dec. 6, 1937 3 Sheets-Sheet 2

<img file="US2158232A_D0003.tif" />

May 16, 1939.

Η. E. GRAU ET AL

DRILLING HOOK Filed Dec. 6, 1937

2,158,232

Sheets-Sheet 3

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Patented May 16,1939

2,158,232

UNITED STATES PATENT OFFICE

2,158,232 DRILLING HOOK Herbert E. Grau and Richard K. Hertel, Vernon, Calif., assignors to Byron Jackson Uo., Huntington Park, Calif., a corporation of Delaware

Application December 8, 1937, Serial No. 178,240

Claims. (CL 294—82)

This invention relates to hoist line hooks, such as are used particularly in the drilling of oil wells. More specifically, the invention relates to the general type of hook disclosed in the patent s to N. K. Smith, No. 1,825,018, issued September 29, 1931, and Involves various modifications and improvements of the hook construction disclosed in that patent.

A broad object of the invention is to provide i- a drilling hook having a hook portion and a hook-supporting portion pivotally connected thereto for free rotation about a vertical axis and also having a universal connection for permitting free swiveling of the hook relative to the ¹ hook-support in any horizontal direction.

Another object is to provide a drilling hook having a hook portion and a hook-supporting portion with a swivel connection therebetween, and means for locking the swivel connection 20 against swivel movement.

Another object is to provide a drilling hook having a hook portion and a hook-supporting portion swivelly connected thereto with a simple and effective brake mechanism for limiting the Λ freedom of swivel movement.

Another object is to provide a drilling hook having a hook portion, a hook-supporting portion, and a swivel mechanism interconnecting the two in which the swivel mechanism is well protected from contact with dirt and debris.

Various other objects, together with the specific features and advantages of the invention, will become apparent from the following description of a preferred form thereof, with reference 35 to the drawings.

In the drawings: .....

Fig. 1 is a side elevation of a drilling hook in accordance with the invention.

Fig. 2 is a front elevation of the drilling hook. 40 Fig. 3 is a vertical section, taken approximately in the plane III—HI of Fig. 2.

Fig 3α is an enlarged detail section taken in the same plane as Fig. 3, to better bring out certain details of construction.

Fig. 4 is a cross section, taken in the plane IV—IV of Fig. 3.

Fig. 5 is a detail vertical section taken approximately in the plane V—V of Fig. 1.

Fig. 6 is a detail cross section, approximately 50 in the plane VI—VI of Fig. 3α.

Fig. 7 is a detail vertical section similar to Fig. 3α, but taken in the plane VII—VII of Fig. 6.

Referring to Fig. 1 of the drawings, our hook comprises as its essential elements a bail I in 65 the form of an inverted U-shaped member adapt ed to be detachably connected to a traveling block or other housing device, not shown, and having its two ends connected to the upper end of a housing 4. The housing 4 contains a spring mechanism for supporting a hook body 33, hav- β ing at its lower end a bill 10 which constitutes the hook proper.

Referring now to Figs. 1 and 3, the lower ends of the bail I are provided with eyes 2 through which extend pins 3 for securing the bail to 10 the housing 4, the latter having a pair of oppositely disposed laterally extending slotted ears 0 (Fig. 2) through which the pins 3 extend.

The housing 4 is approximately cylindrical in shape, except for the protruding ears 8, and is.¹⁸open at both its upper and lower ends. The upper end of the housing 4 is closed with a removable cover 5 secured in position by nut 7 (Fig. 2).

Positioned within, and extending up through 20 the housing 4 is a hook shank 18 (Fig. 3), which hook shank functions to support the hook body 33 from the housing 4. The connection of the lower end of the shank &lt;5 to the body 33 wifi be described in detail later. Suffice it to say that 25 the lower end of the shank 15 passes through an aperture defined by an annular Inwardly extending flange 14 on the lower end of the housing 4, which flange 14 makes a close sliding fit with the hook shank 15 for free vertical movement so of the shank 15 downwardly with respect to the housing 4. Upward movement of the shank 15, with respect to the housing 4 from the position shown in Fig. 3, is limited by an outwardly extending annular flange 27 on the shank 15 which 85 normally bears against the underside of the flange 14. , .

The shank 15 is resiliently supported against downward movement with respect to the housing 4 by a pair of helical springs 18 and 19, re- 40 spectively, which are compressed between a nut 10 on the upper end of shank 15 and the lower end of the housing 4. Thus the lower end of the inner spring 18 rests against the upper face 17 of the flange 14 and the lower end of the 46 outer spring 19 is supported on the upper face of an inwardly extending annular flange 20 on the housing 4, which flange 20 is of larger internal diameter and is positioned slightly above the flange 14. ⁸⁸

The nut 10 is screwed onto the upper end of the shank 15, as previously indicated, and the normal compression of the spring members 18 and 10 may be adjusted by turning the nut 10 on shank 15. It is necessary, however, to firmly lock 55

9,108,989 the nut against rotation after It has once been set. There are several ways In which the nut can be locked; the particular, effective method Is shown in Figs. 3 and 4, In which the extreme 5 upper end of the shank IS, above the threaded portion thereof, Is made polygonal In shape, thereby providing a plurality of flat surfaces 22, one of which is adapted to bear against a fiat side of a wedge-shaped key 21, which key is re10 ceived in a slot 25 formed in the upper end of a nut 10. One end of the slot 25 is closed by a web 21 (Fig. 4) having a hole therein through which extends a bolt 24. The wedge-key 21 is provided with a threaded bore 23α to receive the 15 threads of bolt 24. With the construction described, the nut 10 may be locked in any one of a plurality of positions by turning it so that one of the flat sides 22 of the polygonal end is juxtaposed to the slot 20, inserting the wedge-key 2t 20 and locking it in place with the bolt 24. As shown In the drawings, the polygonal upper end of the shank 15 is triangular, but if a finer adjustment is desired this nut may be made rectangular, hexangular or octangular.

When the load on the hook exceeds a predetermined value, the springs 18 and 19 compress to permit downward movement of the shank IB out of the housing 4. It is desirable that during such separating movement a seal against dirt and 30 other foreign matter be maintained about the shank IB and between the lower end of the housing 4 and the upper end of the hook body 33. To this end we have provided on the lower end of the housing 4 a sleeve 13 which is adapted to 35 ride vertically therealong in response to movement of the shank IB and has a packing ring 13α which slides over a smooth cylindrical surface portion of the housing 4, thereby maintaining a seal with the housing regardless of vertical 40 movement of the sleeve therealong. At its lower end the sleeve 13 is provided with a re-entrant annular wall portion 6S which in turn has an inwardly extending flange 67 thereon, the upper face of which constitutes a shoulder hearing 45 against the underside of the edge of the flange 27 on the shank IB so that the sleeve 13 is constrained to follow the shank downwardly when the latter moves with respect to the housing 6. When the shank IB moves upwardly, with respect 50 to the housing 4, the sleeve IB is forced to follow the shank by contact with the upper end of the hook body 33, which moves vertically with the shank IB. Thus there is defined between the re-entrant wall 6B of the sleeve 13 and a down50 wardly depending skirt 13b on the sleeve, an annular channel in which is slidably mounted for vertical movement a ring 69, which ring is provided with a packing ring 68 sealing with the inner surface of the skirt lib.

The lower end of the ring SB is provided with a concave spherical surface 62 adapted to bear against a corresponding convex spherical surface on the upper end of the hook body 31. The ring 69 is maintained in engagement with the juxta65 posed spherical surface of the hook body IS by a plurality of helical springs 60 which are compressed between a seat β I in the ring BS and the upper end of the channel in the skirt fib, in which the ring BS is positioned. Each of ’the 70 springs 60 is partially enclosed in a cylindrical housing extending upwardly from the upper surface of ring BS, as clearly shown in Figs. 3α, 6 and 7.

In accordance with the invention, the hook 75 body 33 is connected to the shank IB for unlim ited rotation about the vertical axis of the «hank IB and also for swivel movement in any lateral direction with respect to the axis of shank IB. To this end shank IS is threaded at its lower end, within the hook body 33, to receive a nut 5 30 which is secured against accidental rotation of the shank IB in the same manner as is the nut IB (previously described) on the upper end of the shank. This nut 30 is provided with a concave spherical surface 32 having a center of curvature io the same aa the center of curvature of the spherical surface on the upper end of the hook body which bears against the spherical surface 62 on the ring SB. The spherical surface 32 on the upper end of nut 30 bears against a correspond- lo ing convex spherical surface on a lower bearing race 40 of an antifriction bearing (shown in the drawings as a ball bearing), the upper race 3S of which bearing rests in an annular seat 38 formed in the body member 33. The upper race 30, 20 seated in the hook body 33, is rotatably supported on the lower race member 40, which rests against the nut 10 on the shank IB. The body member 33 is thereby rotatably supported by the bearing on the shank IB for unlimited rotation about the 20 axis of the hank. It is also oscillatable in any vertical plane passing through the axis of the shank IB by virtue of the sliding contact between the spherical surface on the nut 30 and the lower bearing race 40. Such oscillatory movement is SO possible without permitting the entry of dirt into the interior of the body member 33 by virtue of the seal between the spherical surfaces on the ring B0 and the upper end of the body 33, respectively, which spherical surfaces have the same 35 center as the spherical surface 32 on nut 30. By virtue of the fact that the ring 60 is constantly pressed into Intimate contact with the upper end of the hook body 33 by the spring 60, sufficient resistance is introduced to sliding movement be- *= tween these surfaces to prevent the body 33 from ⁴⁰swiveling too freely about the shank IB.

It is also desirable that the frictional contact between ring SO and the upper end of the body 33 be utilized to restrain, to a certain extent, rotation of the body S3 with respect to the hous- ⁴⁸ing 4. To this end it is necessary to restrain the ring 60 against rotation with respect to sleeve II and to restrain the sleeve 13 against rotation with respect to the housing 4. Tb this end the ring 69 is provided with an inwardly extending ⁰⁰integral key S9a (Figs. 3a and 6) which extends through a slot 59b provided in the sleeve 13 and into a recess 27α provided in the flange 27 of the shank IB. The key 60α is free to move vertically „ with respect to the sleeve 13 and the shoulder 27 but is restrained from rotation with respect thereto. Accordingly, the ring S9 is at all times constrained to rotate with the sleeve 13 and the shank IS.

To prevent any possibility of the bearing 39 leaving the seat 38 when the hook is not under load, the lower end of the sleeve 13 is shaped to define a shoulder 41 shaped to bear against the spherically curved surface on the upper end of 05 the body 33 and also form on the sleeve 13 an upwardly facing annular shoulder 42 adapted to bear against the underside of the annular flange 27 on the shaft IB. Therefore, when the nut 3B is tightened on the shank 15 into position 70 of proper adjustment, the clearance between the flange 27 and the shoulder 42 and between the shoulder 41 and the body 33 is reduced to such a small value as to prevent any appreciable separating movement between the bearing races 39 75

9,158,889 and 40 or between the upper bearing race SO and lift 8cc&amp; SS·

It is some times desirable to positively lock the hook body SS against rotation with respect to the s shank to and to this end the shank 15 has formed thereon, at a level within the upper portion of the body SS, an enlarged head 28 positioned immediately below the flange 27, which head is provided with a series of vertical slots 43 adapted io to receive a locking member mounted in the body SS. Any desired number of slots 43 may be employed, .but in the particular embodiment shown, four are provided. The locking member in the body SS for cooperating with the slots 43, 15 comprises a lever 44 mounted on a horizontal pivot pin 45 which. In turn, is rotatably mounted in a cover plate or member 46 secured to the body SS and closing an opening leading into the hollow Interior upper portion of the body in which 20 the swivel supporting structure previously described is positioned. As shown in Fig. 5, the cover plate 46 is secured in place by bolts 57.

One end of the pin 45 (the rear end with reference to Fig. 3), extends through the cover plate 25 46 and has a handle 47 whereby it may be rotated. The upper end of the lever 44 extends inwardly and normally rests in one of the vertical slots 4S in the head 28 when the lever is in locked position. The lever Is rotated through a small 30 arc into locked position in which its upper end extends into one of the slots 43 or out of locked position, clear of the head 28, by means of the handle 47. In order to releasably retain the lever 44 in either locked or unlocked position, 3.-, it is provided with a retractable bolt 49 slidably mounted in a longitudinal recess within the lever 44 and projecting therefrom at the upper end. The bolt 49 is constantly urged upwardly by a hollow compression spring 52 positioned in the 40 recess in the lever 44 therebelow. The upper end of the bolt 49 is beveled on two sides to provide two faces SS and 54, respectively, and the cover plate 46 is provided with a boss 51 on its inner surface adapted to be contacted by the bolt 49, 45 and having a surface 55 adapted to be engaged by the surface 83 on the bolt when the lever is in locking position, and having a surface 16 adapted to be engaged by the bolt surface 54 when the lever is in unlocked position clear of the head 28. 50 During movement of the lever 44 from either position to the other, the bolt 49 is first depressed to compress the spring 52, and is then forced outwardly again by the spring so that substantial force is required to move the lever from either 55 extreme position to the other.

The cover plate 46 not only serves as a convenient support for the locking mechanism described, but also gives access to the Interior of the body S3 and facilitates adjustment or re60 moval of the nut 30 and the bearing, including the races SO and 40.

As previously indicated, the hook body SS is provided at its lower end with a bill 70 which extends forwardly-and upwardly and constitutes 65 the hook proper. When the hook is engaged with the bill, it is desirable that the hook opening be closed to prevent accidental escape of the bolt. To this end the bill 70 is slotted at its extremity, as indicated at 71, to receive a closure arm 72 70 which is pivotally connected to the bill by a pivot pin 73. The slot 71 in the bill is extended inwardly substantially beyond the lowermost portion of the bail-supporting surface of the bill to receive an Inwardly extending finger 74 which 75 is formed integrally with the closure arm 7S and when the latter is in closed position the upper surface of the finger 74 is substantially flush with the bail-supporting surface of the bill.

The closure arm 73 Is provided with an aperture adjacent its upper end, which aperture is 5 adapted to receive, when the arm is in closed position, a forwardly extending lug SS formed on the body SS. The upper wall of the aperture in arm 72 and the upper surface of the lug SI are preferably curved about the pivot 73 as a χφ center, so that the arm 72 is free to swing from closed to open position and have relatively small clearance with the upper surface of the lug St when in closed position. By providing relatively small clearance between the juxtaposed surfaces 15 of the lug 88 and the arm 72 when the bill 71 is loaded sufliclently to cause it to yield slightly, the juxtaposed surfaces of the arm 72 and the lug SO will be brought into contact with each other, thereby transferring part of the load to gg the arm 72 and the lug SO and greatly increasing the carrying capacity of the hook.

Should the closure ar.n 72 not be in fully closed position at the time the load is applied to the hook, then the bail or other wedge-supporting gg member will contact the finger 74 on the closure arm, forcing the finger down until its upper surface is flush with the adjacent load carrying surfaces of the ball and positively forcing the closure arm 72 into closed position. 30

It is very desirable, of course, that when the closure arm has been once moved into closed position that it be positively locked against accidental release while at the same time being releasable by the operator. To hold the arm 72 gg in closed position, we provide a latch means, including a reciprocable bolt 82, mounted in the arm 72 for longitudinal motion and adapted to engage a recess S3 formed in the underside of the lug 88. The bolt 82 is supported vertically by &lt;0 a horizontal pivot pin 84 which is mounted in a latch carrier 88 which comprises a slotted frame slidably supported for longitudinal movement in the arm 72 and normally urged upwardly by a helical compression spring 87 positioned there- 4g below.

The upper end of the bolt 82 is beveled downwardly and Inwardly to provide an angular end face 89 and the front underface of the lug 86 is likewise beveled downwardly and inwardly to gg provide an angled latch contacting face 90 so that when the arm 72 is moved from the open position toward closed position, surfaces 89 and 90 will cooperate to press the bolt 82 downwardly, allowing the arm 72 to move into fully closed position 55 in which the aperture therein receives the lug 80, in which position the spring 87 presses the latch carrier 88 and the bolt 82 upwardly, causing the bolt 82 to move into the recess 83 and thereby lock the arm 72 in closed position. 60

Obviously, before the ann 72 can be opened, the bolt 82 must be retracted downwardly a sufficient distance to clear the recess 83 and such downward movement of necessity moves the latch carrier 88 downwardly against the force exerted 55 by spring 87. In view of the fact that the axis of movement of the bolt 82 and the spring 87 is parallel to the vertical axis of the hook body, a sharp blow applied to the body S3 in the direction of its vertical axis might cause the bolt 82 to 70 compress the spring 87 and allow the arm 72 to open accidentally. To prevent possibility of such an occurrence we provide a secondary latch comprising a T-shaped member 93, which, like the bolt 82, is pivotally mounted on the pin 84, the 75

2,158,882 member 93 being positioned in a recess In the front face of bolt 92. The member 93 has a downwardly extending leg 94, the lower end of which normally rests upon a ledge 9b on the arm 5 72 and thereby prevents downward movement of pin 84, and the bolt 82, with respect to arm 72. The member 93 has an upwardly extending arm 97 which bears against one end of a horizontally positioned helical compression spring 98, the op10 posite end of which spring is received in a recess 99 formed in the latch carrier 8S. This spring constantly urges the member 93 to rotate about the pin 84 in a counter-clockwise direction (with reference to Fig. 3), thereby maintaining the U lower end of the arm 94 above the ledge 95 to prevent downward movement of the bolt 82.

The member 93 is provided with a forwardly extending handle or finger 100 for manual actuation, which finger is positioned within a handle «0 “ on the latch carrier 85. Pressing the finger 100 on the member 93 downwardly disengages the lower end of the leg 94 from the ledge 05 to permit downward movement of the latch carrier and the bolt, and the latch carrier and bolt may then be moved downwardly by pressing downwardly on the handle 92. The upper upwardly extending arm 97 of the member 93 normally bears against the rear wall of the recess in bolt 82, in which the member 93 Is partially positioned, so as to limit Μ rotation of member 93 in counterclockwise direction in response to force exerted by the spring 98. The rear wall of the recess also acts as a stop to be contacted by the leg 94, thereby limiting rotation of the member 93 in a clockwise direction in 55 response to movement of the downward force supplied for the finger 100.

It will be observed from Fig. 3 that the bolt 82 is not only urged into upward position into the recess 83 by spring 87, but Is positively prevented 40 from moving downwardly by the engagement of the leg 94 on member 93 with the ledge 95 on the arm 72 and the member 93 is maintained in this position by the spring 98 which is positioned with its axis of movement substantially at right angles 45.to the axis of spring 97. Therefore should the hook receive a blow in a vertical direction capable of displacing the bolt 82 against the resilient force exerted thereon by the spring 87, the bolt would still be prevented from such movement by engage50 ment of the leg 94 with the ledge 95 and since the latter engagement is maintained by the spring 98 positioned at substantially right angles to the spring 87, the blow that might be effective to compress spring 87 would not be effective to compress 55 the spring 98. Likewise, should the hook receive a lateral blow in such direction as to compress the spring 98 and disengage the leg 94 from ledge 95, the bolt would not be opened because such a blow would not be effective to compress the spring 87. 80 The bolt 82 is therefore positively prevented from opening accidentally in response to either a vertical or a horizontally applied blow, and in actual service it has been found impossible to open the bolt 82 in response to a blow applied to the hook 05 in any direction.

However, when it is desired to open arm 72, opening movement is readily effected by first depressing the finger 100 from the member 93 to disengage the leg 94 from the ledge 95 and then 70 move the latch carrier 85, pivot pin 84 and the bolt 82 downwardly either by additional pressure applied to the finger 180 or by downward pressure applied to the handle 92 on the latch carrier.

By virtue of the fact that the finger 100 is 75 positioned back of and slightly below the top of the handle 92, the latter constitutes a guard for the finger 100.

The construction of the latching mechanism described is such that whereas it is necessary to manually depress the finger 100 to release the 5 bolt 82 and permit opening movement of the arm 72, the bolt 82 will be automatically depressed in response to closing movement of the arm 72 so that the latter may be securely locked in closed position by merely slamming it shut. Thus be- jo cause of the fact that the bolt 82 is pivotally attached to the latch carrier 85 by the pivot pin 84, when the arm 72 is moved into closed position, the face 89 on bolt 82 contacts the face 90 on the lug 00, the bolt 02 is rotated about the pin 84 1« in a clockwise direction sufficient to contact the upwardly extending arm 97 on the member 93 and rotate it against the pressure of spring 98, thereby carrying the leg 94 clear of the ledge 95. At the same time pressure between the faces 89 _soand 90 develops a downward component of force on the bolt 82, causing it to move downwardly (following the movement of the leg 94 clear of the ledge 95) with the latch carrier 85 against the force of the spring 87. As soon as the clos- ₂₅ing movement of the arm 72 has carried the upper end of the bolt 82 past the face 90 on the lug 80, the spring 87 urges the bolt 82 upwardly into the recess 83, and as soon as the lower end of the leg 84 moves past the ledge 95 the spring 98 rotates 30 the member 93 to bring the lower end of the leg 94 against the ledge 95, thereby locking the bolt against downward movement until the finger 100 is manually depressed.

To limit the upward movement of the latch _vassembly, including the pin 84 and the elements connected thereto, a roller 104 is mounted on a horizontal pin 105 secured to the arm 72, the roller 104 being so positioned that when the latch bolt 82 is in the closed and locked position shown in Fig. 3, the roller rests upon the upper surface ⁴⁰of the housing 99 containing the spring 98, thereby limiting upward motion of the latch carrier 85 and maintaining the spring 87 under partial compression. The force exerted by the spring 87 maintains the housing 99 against the roller 104 ⁴⁵so that the latch mechanism cannot vibrate or rattle when in the locked position.

As shown in the drawings, particularly Figs. 1 and 2, the hook body 33, in addition to having the main bill or hook 70, is provided with a pair ¹⁵⁰of oppositely disposed arms 107 positioned above the bill 70 and extending at right angles thereto for the reception and support of a pair of elevator links when the hook is employed with an elevator. To retain the elevator links on the arms 107 and ^β,>at the same time support the outer ends of the arms, we provide a pair of latch arms 100 resembling in some respects the arm 72 associated with the bill 70. Thus referring to Fig. 5 each arm _cr. 108 is pivotally attached at its upper end by a pin 109 with an outwardly extending ear 110 on the body 33, the ears 110 being slotted to receive the arms 108 and permit swinging movement of the arms about the pivot pin 109. The lower end _fi5of each arm 108 is shaped to define a head ί 13 adapted to engage the underside of the outer end of the associated arm 107 in load carrying relation when a load is applied to the arm. Thus the juxtaposed contact faces on the shoulder 113 70 and the underside of the arm 107 are substantially tangential with respect to the axis of the pin 109 and there is slight spacing between the surfaces to permit free closing and opening movement of the arm 108. However, in response to a 75

9,168,989 slight downward deflection of the arm lllwhen load is applied thereto, the contacting faces on the arm 101 and the latch arm 100 are brought to bear against each other and thereafter a por5 tion of the load on the arm 101 Is transferred to the latch arm 100.

To prevent any accidental opening of the arm 108 and the resultant possible escape of the elevator balls from the arms 101, each of the 10 arms 108 is provided with a double locking device, which device also functions to retain each arm 100 In fully opened position when desired to permit ready insertion or removal of the elevator \llnks.

This locking device comprises a lever 114 which Is rotatably mounted on the pin 100 and is positioned within a recess formed In the latch arm 108. The lever i 14 is provided with a rearwardly extending finger III and the lever 114 is con20 stantly urged In counterclockwise direction (with reference to Fig. 5) by a torsion spring HI to force the finger HO against the stop lug 110 formed on the latch arm 108 when the latter Is in closed position, and thereby limit counter23 clockwise movement of the lever H0. The lever H9 is normally prevented from rotating out of the position shown in Fig. 6 by the finger HO on lever Π4, the end of this finger being juxtaposed to the lug 122 on lever HO. With the lever 119 30 In the position shown, opening movement of the latch arm 109 is prevented by the fact that the forward face of the lug 121 on lever 119 abuts against a lug 126 formed on the arm 108. The abutting faces of the lug 128 and the tag 126 -. are substantially tangential with respect to the axis of the pin 120 so that any opening movement of the latch arm 108 applies a force from tag 126 and the lug 123 in a direction substantially normal to a radius torsion and from the pin 120.

Of course a purely radial force applied to the lever 119 would not tend to move the latter in either direction but in any event rotation of the lever 119 in response to force applied thereto would be prevented either by the stpp member ₄₆ 124 or the abutment of the lug 122 against the· end of finger 116. In order to open the arm 100 it is necessary to first rotate the lever 114 sufficiently to cause the finger 115 to clear the tag 122 and then rotate~the~lever 119 upwardly and ¢0 inwardly to move the lug 128 out of the path of the lug 125 after which the latch arm 100 may be swung outwardly and upwardly away from the arm 101. - .. .

It will be observed that the lever H4 extends 65 from its pivotal axis in a direction substantially at right angles to the direction from which the lever 119 extends from its pivotal axis. Therefore a blow applied to the lug in such a direction as would tend to open one of the levers will not 00 tend to open the other and disengagement of the latch lug is .impossible without first releasing both levers. The latch lock described is therefore relatively immune to the effect of jars and jolts and is substantially proof against accl⁸⁶ dental release. However, when It is desired to release the latch arm 108 such release is readily effected by first pulling out the lever H* and then pulling up on the lever H9. It is possible ₇₀ to effect both of these operations substantially simultaneously with the fingers of one hand. However, the levers 114 and HO are both substantially completely enclosed within recesses in the arm 108 and the ear HO, respectively, so 75 that there Is little possibility of the levers being δ

engaged and actuated accidentally by contact with acttifr tttenxai object.

¹ Initial opening movement of the latch arm 108 following the rdeaiie of the levers 114 and lit as described, carries the upper face of the lug 6 126 past the outer face 123d of lug IIS, whereupon the lev»: III may be released so that it presses against the outer curved surface of the lug 126 as the arm 108 Is swung open. Pinal opening movement of the arm 108 carries the lug 10 128 past the lug 123, whereupon the lever HO is snapped back Into the normal position by the spring 126 with the face 128 on lug 123 bearing against the outer end 120 of the lug 126, thereby retaining the arm in open position until It is re- 15 leased by raising the lever 110 against the force exerted by the spring 128. The hook described operates as follows:

Assume that the parts are In the normal position shown in Figs. 1, 2 and 3, that the hook Is 20 suspended on a traveling block or other hoisting device connected to the ball i, and that it Is desired to support a load from the hook by means of a bail engaged with the main bill or hook 10 of the device. The latch arm 12 is first opened 26 by bearing down on the finger 100 of the lever 93 to carry the lower end of the leg 94 clear of the ledge 96 on the latch arm 12, whereupon further downward pressure Is applied either to the finger 100 or the handle 92 to carry the bolt M 82 downwardly against the force exerted by spring 81, whereupon the arm 12 may be swung outwardly and downwardly to provide an opening for insertion of the bail to be suspended from the bill 10. The ball is then Inserted and the 35 arm 12 closed by slamming it shut. As the arm moves into closed position, the bevel face 89 on the end of bolt 82 strikes the face 99 on the body 33 causing the bolt 82 to rotate slightly in a clockwise direction about the pin 84 sufficiently 40 to contact the upwardly extending arm 91 on the member 93 and rotate the latter against the force exerted by the spring 98 sufficient to carry the leg 94 clear of the ledge 95, whereupon the downward component of force supplied to the 45 bolt 92 by contact of the face 89 thereon with thd face 90 on the body 33, moves the bolt down to dear the body member and permit it to pass Into the recess 83, the latch arm 12 at the same time moving into fully dosed position, whereupon 50 it Is locked in that position by movement of the bolt 82 Into the recess 83 under the force exerted by the spring 81.

Should for any reason the latch arm 32 not be fully dosed, then when the hook is elevated to 65 apply lifting force to the ball engaged thereby, the ball will bear against the finger 14 on the latch arm 12 and complete the final rotation of the arm 12 to carry It Into fully closed position. With the latch arm 12 In fully closed position, «0 the latch bar 18 is positioned above the lug 80 on the body 33 with very slight dearance between the juxtaposed surfaces. As soon as appreciable load Is applied to the bill 10, the latter deflects slightly to bring the juxtaposed surfaces 05 of the latch bar 18 and the tag 80 together, whereupon &amp; portion of the load on the bill is transferred to the tag 80 and the supporting strength of the bill thereby increased.* If suffldent lifting force Is applied through (he 70 hook structure to the load suspended on the bill 10, the springs 18 and 10 will be further compressed, permitting the shank' 16 and the parts connected thereto to move downwardly with respect to the housing 4 until the lower edge of 75

8,188,989 β

the nut II on the upper end of shank II rests against a shoulder I (Fig. 3) In the housing I. During this downward movement the sleeve 13 is carried downwardly with the shank IB by en5 gagement of the flange IT on the shank with the flange 41 on the sleeve. However, a seal is still maintained between the sleeve 11 and the housing 4 by virtue of the packing ring 13α, so that entry of dirt into the housing 4 is at all 10 times prevented.

During the application of forces insufficient to fully compress the springs II and IB, lifting force is applied from the bail I to the upper end of the housing 4 and thence through the entire 15 length of the housing 4 to the flanges 10 and IT which bear against the lower ends of the springs II and II. However, when the lifting force is increased beyond the strength of the springs II and IB, the nut IB comes to rest against the 20 shoulder 8 and all additional lifting force over that required to compress the springs IB and IB is applied from the bail I only through the upper portion of the housing 4 situated above the shoulder S therein. Therefore the lifting force 25 applied through the portion of the housing 4 positioned below the shoulder S is definitely limited, and this lower portion of the housing can be made relatively light and thin, it being only necessary to make the upper portion of the hous30 ing. down through and including the shoulder portion B, sufficiently strong and heavy to withstand the maximum lifting forces to which the hook may be exposed in use.

If for any reason the load supported by the 35 hook is not directed exactly along the axis of the hook, the body 33 is free to swivel in any horizontal direction with reference to the shank 15 to prevent bending strains being applied to the hook, the swiveling movement taking place 40 along the spherical contact surfaces of the bearing rest member 46 and the supporting nut 32 on the lower end of shank II. If desired, free oscillation between the body 33 and the housing 4 is prevented by friction of the ring 59 against the 45 bearing nut of body 33, contact between these parts further preventing entry of dirt into the interior of the device.

If it is desired to prevent free rotation of the load supported by the hook, the handle 41 Is ac50 tuated to rotate the lever 44 into the position shown in Mg. 3. in which the inner end of the lever engages one of the slots 43, thereby preventing rotation of the body 33 relative to the shank 15. On the other hand, if it is desired to 55 permit free rotation of the load, the handle 41 is actuated to rotate the lever 44 in the opposite direction to carry the inner end of the lever clear of the head 28 and the slot 43 therein. The lever 44 is retained in' either position to which it may GO be moved by friction between the bolt 48 and the cam surfaces 55 and IB. When the lever 44 is disengaged from the slots 43, the body 33 is free to rotate with respect to the shank 15; hence its only contact therewith is through the bearing es member comprising the races 38 and 46 and the smooth surfaces on the upper end of the body 33 and the lower face of the ring IS, respectively.

When it is desired to employ the hook with an elevator having two bails, the latter may engage 70 with the arms 101 by first pulling out on the lever 114 and upwardly on the lever I IB to release the arms IM and then swinging the latter outwardly in substantially horizontal position in which they will be automatically retained by lugs 121 on the >6 levers 118 and the lugs 121 on the arms fB8. The elevator bails are then placed in position on the arms 181 and the arms IBB closed by lifting the levers I IB to disengage the lugs 123 from the lugs 121 and moving the arms 188 into closed position in which they are locked by engagement of the 5 lugs 123 on the levers I IB with the lugs I2B on the arms 108 and by the positioning of the fingers III on levers 114 in juxtaposed relation to the lugs 122 on levers I IS.

Although the invention, has been explained by 10 describing in detail a particular structure in accordance therewith, it is to be understood that various modifications can be made In the particular structure shown without departing from the invention, aijd the latter is to be limited only 15 as set forth in the appended claims.