US2398786A - Chain dredge bucket and method of forming - Google Patents

Description

April 23, 1946." R, HAN KS 2,398,786

CHAIN DREDGE BUCKET AND OF FORMING Original Filed Jan. 21, 1942 2 Sheet-Sheet 1 April 1946 G. R. HANKS -2,39 8,786

I GE RMING eets-Sheet 2 '2 3 Original Fi 111111111111 42 1 the corners of the shoulders.

Patented Apr. 23, 1946 CHAIN DREDGE BUCKET AND METHOD :01?

a FORMING George R. Hanks, Clinton, N. J assignor to Taylor-Wharton Iron and Ste e1 Company, High Bridge, N. J a corporation of New Jersey Continuation .of application Serial No. 427,651,

January 21, 1942. This application January 2 1944, Serial No. 519,669

5 Claims.

This invention relates to a'method of forming the rear eye of chain dredge buckets and providing the same with lining metal and to a chain dredge bucket provided with anovel rear eye, this application being a continuation of my application Serial No. 427,651, filed January 21, 1942, for

' Chain dredge buckets.

with a single relatively wide rear eye and with a 1 pair of front eyes adequately spaced apart so as to receive between them the rear eye of the next adjacent bucket, the two sets of eyes providing for articulation of the buckets byappropriate pintle connection.

Manganese steel is employed because that metal,

when properly heat-treated, has a' characteristic paradoxical tough hardness which makes for long life. However, the casting andflheat-treatment of steel alloys of this type is a .serious problem especially when there is a marked inequality of metal section. Nor is the problem solved simply by overcoming casting .difiiculties. It is solved only by proper heat-treatment of a good casting because it is the heat-treatment that accounts for the tough hardness peculiar to manganese steel. And, althoughthe casting and heat-treatment of manganese steel buckets makes their initial cost relatively high, their long life andgeneral all-around ability t 91 8 with the rigors of dredging makes it an economy to use them.

The rear eye of the conventional chain dredge danger from cracks which are invited by sharp corners, these shoulders are made with, considerable radii in the corners, and the bushing edges are similarly rounded. This necessarily reduces the bearing area between the abutting parts.

The severe battering of the bushing edges against the shoulders impairs them to a degree such that they are not long effective to hold the bushing rigidly stationary, with the result that the pintling is ofi center and this condition is reflected in the pitch of the whole chain of buckets. Y t

According to my invention, chain dredge buckets are cast with a rearl eye freeof bushing stops or the like offset provisions tending to create inequality of metal section. .Dredge buckets so characterized are described and claimed in'Patent No. 2,280,141, granted April 21,1942. The rear eye so formed is ground or machined so that it presents a symmetrically full round or cylindrical bore for the reception of lining metal to receive the barrel of the linkage pin coaxial relation with the front eyes. The liningcomprises facing arcuate members whereof one is a wear compensating bushing, and whereof the other is a filler, or bushing stop. H

The bushing. stop is adapted'and arranged for positive interlocking connection with the rear eye in order adequatelyto function to prevent rotary shift "of thebushing. .The bushing stop may preferably be a unitary structure insertible from either-end of the rear eye or it may be in V Ineither case the outerends of the bushing stop are welded to the bucket by sectional lengths.

the-electric arc process. l

The bushing and bushing stop may be pre-conditioned in order to minimize peening or cold flow bucket is cast with concentric arcuate walls. 1

The larger arc serves to accommodate an ining of substantially semicircular section. The

purpose of the smaller arc is to prevent rotary shifting of the bushing and, to that end, has anvil surfaces or shoulders in abutting relation with the arms of the bushing. Such differential arc construction makes for inequality of metal section and, hence, gives rise to foundry difiiculties in casting and heat-treatment so that. an apparently sound casting may have inherent or potential zones of weakness located radially near To minimize the after the manner set forthin my U. S. Patent No. 1,701,976, granted Feb. 12, 1929. A

My improvements and the manner in which the benefits flowing therefrom may be realized in practice, will be readily apparent to those skilled in the art by reference to the accompanying drawings, wherein:

immediately adjacent bucket by means of a linkage pin. v a v In a simple embodiment of the inventibmthe bushing 8, Fig. 2, which may bethe conventional bushing, is retained in proper functioning position by a filler or lining member 9.

The latter cular stop member having abutment end surfaces of the full thickness of said member, dovetailing and welding said stop member to the forward segment of said eye, and thereafter inserting in the rear segment of said eye an approximately -semicircular renewable bearing bushing with its formed in substantial coincidence with the bushthat is to say, it is a unitary arcuate shaped member substantially the major dimensionof-the rear eye, the main difference between the two lining members being that thestop or filler is secured in positive fashion against angular or rotary movement in order that it, in turn, will be capable of successfully resisting rotary shift of the bushing. Oneway of accomplishing this is to provide the rear eye with: a through slot ill to receive a corresponding offset or key 1,] ranging m l a d 'l n tu ma y of e bush ng stop. Thera s mb bushin comp em nt 9 is applied ate way, preferably the outer ends of the key ll 'andfil-lerl are beveledas at|,2 whereby, in conjunction'with adjacent portions of the rear eye,

e e t n f e d d po it metal 13. g

Under preferred practice the filler or bushing stop 9 is 'in one length as in Fig. 13, and is provided with? dovetail key I}. Therear eyehas anomplemental slot l1] shaped .to fit thekey, and proe vides, a tongue and groove inter-lock. Likewise in this embodiment, .or in any other embodiment Within the scope of my invention,",proyisionli .or

be made forv differential hardness'of the I bushing and bushing stop members, particularly t the impaotareasthereof. I 7

Having described my in,veritiorrl?,clafim:

1. The methodof forming aillinedrear eye of a chain dredge bucket whichjincludes" theisteps o casting the bucket with a rear ,eyewh'ich is .subt nt all t r' ar in ro ect n m chine g indin e nt'eri r sylind i al wall ofisaid eye, eparate y r v in an, a proximatei semicir-- cular stop member havingabutment end surfaces of the full thickness of said member, .doveta ling said stop member with the forward segment of d eye and e eaf e inser ing in he rear se ment of said eye :an approximately semicircular renewable bearing bushing with itsendjsurfaces ,30 from either end of the rear eye and is secured against "longitudinal movement in any appropritoss a s b tan ial vhap 'd po ket is formed for the end surfaoesin abutting relation to the end surfaces of said stopomember.

3. Thezmethod of'forming a lined rear eye of a chain dredge bucket which includes the steps of casting the bucket with a rear eye which is substantially circular in cross section, machine grinding theinterior cylindrical wall of said eye, separately providing an approximately semicircular stop member having abutment and surfaces of the full thickness of said member, forming a dovetail interlock between said member and the forward segment of said-eye throughout the axial width of said member, welding said member to the wall of said eye, and thereafter inserting in the rear segment of said eye an approximately semicircular renewable bearing bushing with its end surfaces in abutting relation to the .end surfaces of said stop member.

4. The method of forming a linedrear eye of a chain dredge bucket which includes the steps of casting the bucket'with .a rear eye which is substantially circular in cross section, machine grinding the interior cylindrical Wall of said eye,

separately providing an approximately semicircular stop member having abutment end surfaces of the full thickness of said member, hardening the abutment end surfaces of said member, dovetailing and welding said member to the forward segment of said eye, and thereafter inserting in the rear segment of said eye an approximately semicircular renewable bearing bushing with its end ,surfaqes in abutting relation to the end surfaces of said stopmember.

5 A, chain dredge, bucket cast with a rear eye which is Substantially circular and machine ground, an approximately semi-circularstop member dovetailed into and welded tp'the for- .wardsegment of the eye and providingabutment end surfaces of the full thickness of said stop member, saidend surfaces being hardened, and an approximately semi-circular renewable bearing bushing in the rear segment of the eye and contacting With the-hardened end surfaces thereof to prevent circumferential movement of said bush n w r l fcEoR E a.

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