US3865423A

US3865423A - Safety hook

Info

Publication number: US3865423A
Application number: US388337A
Authority: US
Inventors: Lloyd D Ross
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-08-13
Filing date: 1973-08-13
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11

Abstract

Disclosed is a safety hook having a bight whose outer side is formed by a pair of upwardly and outwardly diverging legs and a saddle formed between the legs. A nose extends transversely from the shank of the hook to a position between the legs and above the saddle. A shackle or ring being attached to the hook must be placed on one leg, twisted over the end of the other leg and under the surface of the nose before seating in the bight. Once seated, the shackle must undergo substantially the same set of motions in reverse for removal; it is extremely unlikely for such motions to occur by accident during jarring of the hook.

Description

United States Patent [191 Ross [451 Feb. 11, 1975 SAFETY HOOK [22] Filed: Aug. 13, 1973 [21] Appl. No.: 388,337

[52] US. Cl 294/82 R, 24/2305 CR [51] Int. Cl. B66c l/34 [58] Field of Search 294/74, 78 R, 82 R; 24/2305 R, 230.5 AD, 230.5 LH, 230.5 CR,

230.5 CS, 230.5 TD, 230.5 TP, 230.5 T, 241

R, 241 CH; 59/78, 85, 89, 93

3,354,521 11/1967 Plett 24/2305 CR Primary Examiner-Evon C. Blunk Assistant Examiner.lohnny D. Cherry Attorney, Agent, or Firm-Clegg, Cantrell & Crisman [57] ABSTRACT Disclosed is a safety hook having a bight whose outer side is formed by a pair of upwardly and outwardly diverging legs and a saddle formed between the legs. A nose extends transversely from the shank of the hook to a position between the legs and above the saddle. A shackle or ring being attached to the hook must be placed on one leg, twisted over the end of the other leg and under the surface of the nose before seating in the bight. Once seated, the shackle must undergo substantially the same set of motions in reverse for removal; it is extremely unlikely for such motions to occur by accident during jarring of the hook.

6 Claims, 6 Drawing Figures SAFETY HOOK BACKGROUND OF THE INVENTION The conventional method of attaching a load to a line for lifting and lowering purposes is by use of a hook attached to the lower end of the loadline and by the use of one or more shackles, rings, links, cable loops, or similar devices which are seated in the bight of the hook and are connected to cables or chains which are wrapped or slung around the load. Conventional hooks are strong compact devices, usually forged from steel or iron, and have a ring portion for attachment to the lifting line, a shank portion, and a bight portion below the shank portion, which bight is partially open at one side so that a shackle or other loop-like device can be readily inserted into and removed from the bight.

By their nature, lifting and lowering operations are often rather violent, involving jerky starts and. stops, swings and gyrations, and collisions with stationary objects beside, below, or above the load being lifted or lowered. These violent movements create momentary occasions when the normal tension system between the lifting line, the hook, the shackle and the load is disrupted or even put into compression. Since it is the condition of tension which is relied upon to keep the lifting ring or shackle seated in the hook, there are thus many momentary opportunities for the shackle to be jarred out of the hook, with often disastrous results.

Various kinds of safety hooks have been employed or proposed in the past. The type which has come-into most widespread use involves the provision of a spring loaded closing finger for closing the normally open side of the hook bight. This type of safety hook has several disadvantages. The movable finger can never be as strong as the hook proper, and is liable to damage and breakage. The moving mechanism is also liable to corrosion and freezing or seizure. Furthermore, many workmen do not like the complication introduced by I U.S. Pat. Nos. 399,831; 735,445; 1,101,815; 1,224,148; 1,649,655, 3,131,452; 3,233,933; 3,668,746.

Recently, increased attention has been given to the problems of industrial and occupational safety, including the enactment of rigorous legislation in the field, and this has intensified the need for improved safety hooks for use in lifting applications.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided an improved safety hook for use in lifting and lowering applications. In its preferred form, the hook is of one-piece construction, and has no moving parts. It is so proportioned that it can cooperate with a wide variety of the commonly encounteredtypes of loop-like lifting means, such as shackles, rings, links and cable loops.

The hook of the invention has a lifting eye portion, which may be of any of a wide variety of forms, but which in any event is designed for permanent or semipermanent connection to a lifting line. Beneath the lifting ring portion is a shank portion. Beneath the shank portion is the hook proper, or the bight. The bight is closed at one side and at the bottom, as in a conventional hook. It is provided with an open side of special form; the open side includes a pair of upwardly and outwardly flaring legs having a saddle between them. Projecting from the shank or the top of the bight is a nose portion, which extends toward the open side of the bight in a position between the legs and above the saddle. The parts are proportioned so that the space between the inner surfaces of the legs and the side and bottom surfaces of the nose is only slightly greater than the thickness of a shackle or other loop-like device which is to be inserted into the bight of the hook.

When a shackle is being installed on the hook, it is first lifted over one of the legs of the open side, in a manner much like it would be lifted over the distal end of a conventional hook. The shackle is then twisted and passed over the end of the other leg of the bight and under the before mentioned nose. Finally, the shackle rotates downwardly and is seated in the bottom of the bight. Tension isthen applied to the lifting system to lift the load, the force being transmitted axially through the hook and shackle.

If, through ajerking motion for example, the tension is momentarily removed from the hook and shackle system, the shackle will move upwardly with respect to the hook. It is extremely unlikely that such movement will result in detachment of the shackle from the hook, because the overlying nose will restrain movement of the shackle in the generally upward direction with respect to the hook and the outwardly flaring legs will restrain movement of the shackle outwardly of the hook. Only if the jerky release of tension from the hook and shackle is so violent that the shackle undergoes substantially the same motions in reverse that it went through during installation will it become disengaged from the hook. The odds against this happening are enormous. Even if the jerky motion is quite violent, and the shackle moves off of one leg and under the nose of the hook, it will still be engaged by the other leg of the hook and restoration of tension at this point will leave the parts engaged, albeit in a less than completely satisfactory manner. It is thus an important feature of the invention that the overwhelming odds favor maintaining engagement of the shackle with at least one leg of the hook, even if, against even greater odds, the shackle becomes disengaged from the main bight of the hook.

It is an object of the present invention to provide an improved safety hook, especially useful in load lifting applications.

A further object of the invention is the provision of an improved safety hook having two modes of engagement with a loop-like lifting shackle, the first or main of said modes being one from which it is almost impossible to accidentally disengage the shackle, and the second of said modes being an emergency engagement mode into which the shackle is most likely to locate itself upon being accidentally disengaged from the first mode.

It is a further object of the invention to provide a safety hook which is easy to manipulate, and which has safety features that cannot be disabled or ignored by a workman using the hook.

The foregoing objects and purposes, together with other objects and purposes, can be best understood from a consideration of the detailed description which follows, together with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan sectional view of a hook constructed in accordance with the invention, the section being taken along the line 1-1 of FIG. 2;

FIG. 2 is a side elevational view of a hook constructed in accordance with the invention;

FIG. 3 is a front elevational view of the hook of FIG. 2, the view being taken looking in the direction indicated by the arrows 3-3 on FIG. 2;

FIGS. 4, 5 and 6 are diagrammatic front views similar to FIG. 3, showing three successive stages in the application ofa shackle to the hook for load lifting purposes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The safety hook of the invention is designated generally as 10 in the drawings. As can be seen best in FIG. 2 the hook includes a lifting ring portion 11, a shank portion 12, and a bight portion 13.

The embodiment shown in the drawings has a ring portion 11 which lies in the principal plane of the bight 13, or of the hook as a whole. Those skilled in the art will appreciate that the ring portion 11 may be configured differently; in particular, the ring may be oriented in a plane perpendicular to that of the bight 13 or of the hook as a whole. Furthermore, in some applications, it

may be desirable to employ a swivel mounted ring portion. The function of the ring portion is to provide a means for securing the hook 10 to a lifting line, and for the purposes of the invention any of the conventional means which have proved satisfactory or useful in the past may be employed for this function.

The shank 12 in the hook shown in the drawings is relatively short. Its function, in accordance with the invention, is to connect the ring portion 11 (or other device used to connect the hook to a lifting line) to the bight 13. If it is desired for any reason to have a long shank, such can be provided without departing from the invention.

Bight 13 has a closed back side 14 and a closed bottom 15, both of which are configured much in accordance with good conventional hook design practice. The bight 13 also has an open side 16 which provides an access route into the interior of the bight for a lifting ring, shackle or cable loop which is attached to the load to be lifted. Open side 16 is specially configured in accordance with the invention. In particular, it has two

legs

17 and 18 which project upwardly, and outwardly in opposite directions, generally in a plane transverse to the main plane of the bight or of the hook as a whole (see FIG. 1). Between

legs

17 and 18 there is formed a saddle 19 which is also part of the open side of the bight. Saddle 19 is positioned up the side 16 some distance from the top surface of the bottom of the bight.

In accordance with the invention, a nose 20 projects from the part of the hook where shank portion 12 joins the closed back side 14 of bight 13. Nose 20 projects outwardly toward the open side 16 of the bight. It projects between legs 17 and '18 and above saddle 19.

The lower surface of nose 20 is shown in FIG. 2 as being angled somewhat upwardly to the right as that figure is drawn, and this is the preferred configuration. However, the bottom surface of nose 20 need not be configured in this manner.

Legs

17 and 18, nose 20 and saddle 19 are positioned and proportioned with respect to each other with a view to the dimensions of the shackles, lifting rings, cable loops, and other loop-like devices with which the safety hook 10 will be used. A given safety hook may be designed to cooperate with any one of a number of loop-like devices in a given size and strength range or it may be designed to cooperate with a specific looplike device and form a set therewith. On the other hand, the proportioning of the remaining parts or portions of the safety hook 10 need be less closely correlated to the proportions of the loop-like member with which the hook is to cooperate. For example. a very deep bight may be provided instead of the relatively shallow one illustrated in the drawings, or a very long shank may be used.

The following considerations bear upon the proportioning of

legs

17 and 18, nose 20, and saddle 19 with respect to each other and with respect to the loop-like member. At their closest approach, the surfaces of nose 20 and

legs

17 and 18 should be spaced apart slightly greater than the thickness of the rod-like material forming the loop-like member. The distance between

legs

17 and 18 at their outer extremities is preferably greater than the minor diameter of the loop-like member, if such member is other than round and in fact has a minor diameter. The distance between the base portion (i.e., the portion lower than saddle 19) of

leg

17 or 18 and the tip of the other leg is less than the major diameter of the loop-like member. The ends of

legs

17 and 18 extend above or overlap the bottom surface of nose 20 (see FIG. 2).

The importance of the foregoing. proportional considerations may be better understood by a consideration FIGS. 4 through 6 which show three successive stages in the installation of a lifting shackle 21 onto a hook l0. Shackle 21 is typical of the loop-like members with which the hook may be used. The shackle 21 is formed of rod-like material bent into a U-shape with a pin 22 closing the open end ofthe U. Shackle 21, as can be seen from FIGS. 4 through 6, is one of the loop-like members which has a major diameter (up and down in FIG. 6) and a minor diameter (left to right in FIG. 6).

In connecting the shackle to the hook, shackle 21 is first lifted over leg 18, as is shown in FIG. 4. Then shackle 21 is manipulated so that its major diameter is aligned with the base of leg 18 and the tip of leg 17, as appears in FIG. 5. In addition, one side of shackle 21 is passed under nose 20. The shackle is then twisted over the tip of leg 17 and to the position shown in FIG. 6. The hook and shackle combination are thus ready to perform their lifting function.

From a consideration of FIGS. 2 and 6 together, it can be seen that if the normally tensioned system of hook 10 and shackle 21 is suddenly jolted into a nontensioned position, the shackle 21 will tend to ride upwardly in the bight of the hook. However, it will not move out the open side 16 of the hook because its upward movement is restrained by nose 20 and its outward movement is restrained by

legs

17 and 18. The interference provided by these parts prevents shackle 21 from jumping off the bight of the hook. This is true even if shackle 21 is tilted to a great extent in its upward movement. Only if shackle 21 goes through a sequence of motions and twists substantially the same as those used to insall it on the hook, but in reverse sequence (FIG. 6, then FIG. 5, then FIG. 4), will the shackle move even part-way out of the bight of the hook. Such a series of jolt induced motions is extremely unlikely to occur.

Even if, through jarring and jolting, the shackle 21 becomes disengaged partially from the bight and from one leg (such as 17), it is still engaged by the other leg (leg 18) and will most likely seat on saddle 19, instead of separating from the hook altogether. While the condition of being hooked over one leg of the hook is not a completely satisfactory mode of attachment of a lifting means portion adapted for attachment to lifting means; I

an integral depending bight portion, said bight portion comprising:

a bight having a closed side, a bottom, and an open side for receiving a loop-like lifting member into the bight;

the open side of said bight having a pair of upwardly and outwardly diverging legs terminating above the bottom of said bight, and a saddle between said legs;

and a nose portion extending from the closed side of said bight, across and above the bottom thereof to a point between said legs and above-said saddle.

2. A safety hook in accordance with claim 1 and further comprising a shank interposed between said lifting means portion and said bight.

3. A safety hook in accordance with claim 1 in which the bottom surface of said nose portion slopes upwardly from the closed side of said bight.

4. A safety hook in accordance with claim 1 in which said lifting means portion comprises an eye portion.

5. A safety hook in accordance with claim 4 in which said eye portion lies in the plane of the bight.

6. A safety hook in accordance with claim 1 in which the ends of said legs extend above the bottom surface

Claims

1. A safety hook for detachably engaging a loop-like lifting member such as a cable loop, shackle, link, or ring, comprising: a lifting means portion adapted for attachment to lifting means; an integral depending bight portion, said bight portion comprising: a bight having a closed side, a bottom, and an open side for receiving a loop-like lifting member into the bight; the open side of said bight having a pair of upwardly and outwardly diverging legs terminating above the bottom of said bight, and a saddle between said legs; and a nose portion extending from the closed side of said bight, across and above the bottom thereof to a point between said legs and above said saddle.

6. A safety hook in accordance with claim 1 in which the ends of said legs extend above the bottom surface of said nose.