US2820662A - Chain guard for overhead hoists - Google Patents

Description

Jan. 21, 1958 T. WALKER 2,820,662

CHAIN GUARD FOR OVERHEAD HOISTS Filed Oct. 4, 1956 2 Sheets-Sheet 1 I NVENTOR THOMAS WALKER ATTORNEY Jan. 21, 1958 WALKER 2,820,662

CHAIN GUARD FOR OVERHEAD HOISTS Filed Oct. 4, 1956 2 Sheets-Sheet 2 1; INVENTOR l7 THOMAS WALKER ATTORNEY United States Patent CHAIN GUARD FOR OVERHEAD HOISTS Thomas Walker, Chester, Pa.

Application October 4, 1956, Serial No. 613,992

Claims. (Cl. 294-78) The present invention has reference to guards or protective means used particularly in connection with overhead hoists or similar heavy duty apparatus.

Overhead hoists or cranes usually include a traveller or block from which are suspended a plurality of chains, usually four in number, to be secured at their lower ends to the heavy and bulky load to be elevated and transported. In instances where the load is extremely heavy, or is of unusual size, it is customary to use all of the chains, attached in spaced relationship at their free ends to the load in order that the latter may be properly balanced for lifting or transportation purposes. However, it frequently occurs that two of the depending chains are suflicient to support the load, in which event the free ends of the unused chains are usually temporarily attached, as by their hooks, to the ring or other part of the crane so as to be out of the way and not to interfere with the free and proper operation of the crane itself. It sometimes happens, however, that the free ends of these unused chains become accidentally detached from the overhead support, thus liberated giving rise to injury to nearby workmen or possibly seriously interfering with the proper operation of the work.

The device of the present invention is developed to guard against this danger, and includes means whereby dropping of the chain ends from their support to the danger zone will be avoided.

A further object of the invention is to provide a guard of such construction that it may be quickly and easily attached to overhead cranes or other similar types of machinery of present day use and which will effectively hold the free end of a suspended chain from dropping to such position as might cause danger of injury to workmen or interference with the proper operation of the mechanism.

A further object of the invention is to provide a guard of extremely simple construction which may be manufactured at low cost, which may be attached to modern cranes quickly and easily and without the exercise of special skill or training, which will prove highly effective in its operations and which may be readily detached from the crane or other machine when desired. With the foregoing objects in view, together with others which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts, all as will be described more fully hereinafter, illustrated in the drawing, and particularly pointed out in the claims.

In the drawing:

Fig. l is a perspective view of a conventional overhead crane structure illustrating the application thereto of guards embodying my invention,

Fig. 2 is an enlarged detail side elevation showing the guards in association with the crane and in the position they will assume when attached to the chain lengths not m use,

Fig. 3 is an end elevation of the device shown in Fig. 2, taken on line 3-3 thereof, and showing the free end 2,820,662 Patented Jan. 21, 1958 of the suspended chain confined within the guard sleeve,

Fig. 4 is a side elevation of one of the guards showing the hook at the free end of the chain engaged with the rim of the sleeve,

Fig. 5 is a transverse sectional view taken substantially on line 55 of Fig. 4, and

Fig. 6 is a side elevation of the invention showing the hook of the free end of the chain in a slightly different position.

The invention is here illustrated in connection with a standard or well known type of overhead crane, but it will be understood that the invention may equally as efiectively and efliciently be used in connection with other types of machinery; in fact, it may be adequately used in connection with any type of machinery of this general character where free swinging chain ends may be a detriment to safety.

In Fig. l of the drawing, the overhead crane or traveller is represented generally at 6 and includes a relatively heavy block or sheave as shown having an attaching ring or loop 7 depending from its lower end. This ring has secured thereto the upper ends of the supporting chains 8, being attached to the ring or loop either by hooks or by rings 9 as indicated. The lower or free ends of the chain 8 are provided with hooks 10 to be engaged with the load for the support of the latter. In instances where the load is extremely heavy, or where it is bulky, all four of the chain lengths are used in order to either equally distribute the weight of the load or to properly balance the latter in the operation of the crane. However, it frequently occurs that only two of the depending chains need be used in handling the load, in which event the. remaining or unused chain lengths are doubled upon themselves as shown in Fig. 2 with the hooks 10 at their free ends engaged either in one of the upper links of the chain or in the ring which attaches it to the ring or loop 7 of the crane. It is usual that the hooks 10 are of considerably greater transverse dimension than the links of the chain 8.

A guard of my invention is provided for each of the chain lengths not in use. This guard comprises an elongated sleeve made of suitable relatively thin metal indicated at 11 having spaced arms 12 at its upper end to straddle the ring or loop 7, a bolt 13 passing through suitable openings in the arms 12 above the ring or loop 7 to retain the guard in suspended relationship from the ring 7. A wing nut 14 may be engaged with the end of the bolt to secure the same removably upon the depending ring 7. The sleeve 11 is cut away for most of its length but near its lower end is tapered or restricted to provide a neck as at 15. This restricted portion is free of the sleeve at one side and is provided with an outwardly directed flange 16 through which a bolt 17 passes and extends through a similar flange 18 on the body of the sleeve; a wing nut 19 may engage with the threads of the bolt to hold the restricted neck portion in proper closed position. The restricted neck portion is of sufiicient transverse diameter to permit of the accommodation of the chain 8 doubled upon itself, but is of less transverse diameter at its lower end than the transverse diameter of the hook 10 at the free end of the chain. The upper end of the restricted neck portion 15 of the sleeve provides a ledge 20 as shown.

It will be understood that a guard sleeve of the type here described is provided for each of the chain lengths to be guarded. The restricted neck portion of the sleeve 11 may be opened by removing the bolt 17 so that the chain may be passed to the interior of the restricted neck portion laterally, after which the bolt would be applied and the wing nut tightened, thus confining the chain within the sleeve. With the hook 10 engaged either in one of the links of the chain or with the ring or loop withits back against the. trough of the sleevel la soQthat in f il fief 'h kfw g i h t. ne se wi he. led eas shown in Fig. 14 or will" wedge'li'n f the. restricted 'neck portion 115" of-th'e sleeve 'asin Fig, 3. 1 7

,m 'SIW F Q iQ Q it ap a entha h f e end 'of the chain doubled uponi'tsfelf will be positively prevented from dropping b'eygnd the restricted neck por tion ZlS of the guardfeither by engagementofthe'hook 10 over the shoulder or ledge 29 of the sleeve or within the restricted neekporti'on of the sleeve. The use of the guard thus insures against any injury 'to 'adjacen't workmen orinterference with theproper operation of the crane y whipp c fi et-1 winins chains s has heretofore'occnrred. V

It will be o' bservedythat the guard Jispso constructed that it may "be easily and quicklyattached to various types of 2 i ft is la m L s". simple ope a io and without thefexerciseof special skill or knowledge, yet at all times absolutely preventsthe'chain end 'from becoming detached; Being made of re'lajively steel fthe guard y h sfl te nle meth dsr nd; alt m n mumofxexpense, atth esarne "time proving, at "times efiective'in carrying out the purposes forwhieh i't is designed. Y V

-1. In combination, a'movable supporthaving the upper end o f a tree swinging chainpermanently. attached thereto with a hookat'the free end of the chain of greater transverse dimension than said chain; of a sleeve swingingly engaged at its upper end with said support in depending relationship therewith and being of less length than the chain, a restricted neck portion at the lower end of said sleeve loosely enclosing said chain, said restrictedportion of said sleeve being of less diameter than the transverse dimension of said hook. i

Asgard-far: 355 16 s in n ho s h l w ic is attached at its upper end to a movable support and having a hook at the-tree'end thereof,- comprising a sleeve 0t less length than; the chain suspendedinparallel relationship with the upper end of said chain and enclosing a depending portion thereof; said-'hook -being of greater a hook from passing .therethrough.

transverse dimension than said chain, the lower end of the sleeve having a restricted portion of a diameter less than the transverse dimension of thehook to prevent said 3. Aguard as set forth in-claim 2, wherein the restricted portion of lthe. sleeveis open at one side, flanges on the,

: the chain andof lessglength than the rlatter the lowen end of J the. sleevetfhaving, a restricted; neck portion and being; of. a diameter smaller thauthe transverse dimension of the hook to. prevent; the hook. ;from passing therethrough.

Noe i mes i ed

Images