US2349021A - Safety crane hook - Google Patents

Description

May 16, 1944-.V

F. J. TRUESDALE ETAL SAFETY CRANE HOOK y Filed Nov. a', 1941 Patented May 16, 1944 1 vHarry Kermit Fish', Follanslne,W.Y Va., assignors to National SteelGorporaton, a'orporation of Delaware Application November 8, 1941,l Serial No. 418,410

(Cl. 294-483) Q 1 Claim.

The present invention relates to improvements in safety devices for crane or derrick hooks to prevent accidental disengagement of the load from the hook.

In steel mills and other industrial environments, stationary derricks and travelling cranes move large loads from place to place. In order for the derrick or crane hook to lift the load there rmust usually be a load handling device, such as chains, platforms with lifting baiis, or special equipment to support the objects to be lifted in such a manner that the hook can engage and disengage the same. All such load handling devices are extremely heavy and cumbersome. When the crane is lowering the load and the load comes to rest upona support, further movement of the hook often disengages those parts of theload handling device engaged with the hook catching the operator adjacent the hook unawares. Many fatalities occur from this source when the liberated parts of the load handling device strike an operator.

The present invention obviates this hazard by giving the operator of the hook full control at the point at which the load handling device is released from the hook. The present invention provides a bar or guard for closing the mouth of the hook. This feature alone is not new over the prior art, but further provision is made for automatic closing movement of this bar -and ready control of its opening movement by the operator. The hook itself is designed so that the bar in inoperative position will not interfere with movement of bails and the like into and out of the hook mouth. These desiderata are achieved Without the strength of the hook being reduced or the operating efficiency ofthe crane lowered.v

An important object of the present invention is to provide a crane hook having a safety feature preventing accidental'engagement of the load.

Another important object of the present invention is the provision of a safety crane hook which allows engagement with a load at all times but prevents accidental disengagement thereof.

A further important object of the present invention is the provision of a guardv for crane hooks positively maintained in operative position relative rto load engaging devices engaged by the hook.

A still further object of the present invention is the provision of a guard for crane hooks which shall be out of the way in inoperative position.

Other objects and advantages of this invention will-become apparent fromthe following detailed description thereof, reference being had to the accompanying drawing which constitutes part of the presentdisclosure and wherein;

Figure 1 is a view in elevation of a structure embodying the present invention;

Figure 2 is a. View in cross-section taken on the line II-II of Figure 1; and

Figure 3 is a view in-cross-section taken on theline III-III of Figure 1.

` Referring more specifically to the drawing, referencenumeral IIJ designates generally the body portion of a hook for cranes and the like which I incorporates a shank I I and a hook-shaped member I2. The body portion at I3 defines a recess, opening in a mouth dened by lips I4 and I5. Adjacent `the shank and in the neighborhood of vthe mouth of the hook, the body portion is slotted at I6 to form legs I1. Legs II are drilled at I'I'in a direction perpendicular to the bifurcated section. Rotatably mounted in the drill holes I1' is a pivot pin'l. Rigidly mounted on pivot pin IB and depending therefrom is a bar or guard I9. ByV rotation of pin I8, guard I9 moves between two' extreme positions. In the vertical position shown in Figure 1 in full lines, the lower end of guard I9 fits into a recess 20 in the lip I4 of the body portion of the hook. In its other extreme position guard I9 is received between the legs of the slotted section Ivi, as shown in dotted lines in Figure v1. Outside legs I1 pivot pin I8 carries an operating handle or arm 2I, which is rigidly connected to the pivot pin. Movement of arm 2I from the position shown in full lines in Figure l to the position shown in dotted lines results in movement of guard I9 between its two extreme positions.

With the hook hanging in its customary position, as shown in Figure 1, the weight of handle 2I maintains guard I9 in abutment with lip I4 at recess 20 which `thus acts as a stop to limit movement of the guard past operative position. When the bail or hook engaging element of the load handling device is to be engaged by the hook, it may be pushedy into the mouth of the hook against the'resistance presented by bar I9 due to the weight of. arm 4I. If desired the operator at the hook may `lift handle 2l to withdraw guard I9 out of the way.` When disengagement of the load handling device from the hook is desired, handle 2| must be raised and when raised to its Yextreme position as shown in dotted lines in Figure 1, any interference of the guard with the load handling device is eliminated because legs II of the A:bifurcated section of the body portion enclose the guard throughout its length. Recess 20 protects the end of the guard when the same is operative position.

Although the preferred form of the present invention is herein shown and described, it will be obvious that departure therefrom Within the scope of the invention can be readily made. The invention is, therefore, not tobe 1i mv ited by the present disclosure exbept as 'hereinafter dened by the claim.

We claim:

A safety hook for cranes and the like compris'v' ing a body portion including a shankgthebody portion being formed in the shape` of a hook` to dene a recess opening in amou'th',,aslotin'the' body portion presenting I l ci, I A ta; ,pin passing through the legs and rotatable relative thereto, a guard rigidly mounted on therpin between the legs movable between an operative and inoperativeposition and closing the mouth in operative position, an arm extending around the body portion and having rigid attachment with the pin outside, each leg, the arm making an angle with i the guard such that the weightfof the arm maintains the guard in operative'po'sition.' and a stop lmeans limiting movement of the guard in operative position, the arm in such position being maintained out of contact with the body portion.

FREDRICK J. TRUESDALE. l HARRY KERMIT FISH.

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