US2332293A - Coiling block - Google Patents

Description

Oct. 19', 1943. A. G, IBLQDGVETT CO ILING BLOCK Filed Feb. 20, 1942 ,Patented Oct. 19, 1943 I Alberto. I

Morgan Constructi Mass; a corporation Application coil has been completed, the, block. and coil are withdrawn axiallyfrom the arbor and up-ended to bring the axis of the-block vertical. The'coil is then subjected to a' .fspinning laction bMbIinging about a relative rotation between the :block and the outer portion of the coil, this rotation being in the proper'direction to loosen the convolutions of the coil,"whereupon the block can be withdrawn axially from the coil; Whenthe strip is wound under high tension, as-is often desirable, it subjects the blockto heavy compressive loads. If the block is made of sufficient thickness and otherwise constructedto withstand these loads,'it will be so heavy that itcannot'be handled manually, and a crane or other mechanical apparatus may be required "to lift it out of the spun coil, Furthermore'when a thickfwall cylinderis" subjected wan external radial coinpressiveload, asby the winding, of strip thereon under tension, the maximum tangential stress ocours in the fibers" adjacent the'bore of the cylin der, and the stress in the other fibers is'pro'g'ressively less as the outer surface of the cylinder is approached; Since it is the maximum stress which determines the maximum permissible load mg, it is apparent that soon afconstruction results in an inefiicient utilization of themetalL'f A further disadvantage inherent in priorblocks' resides in the fact" that as the wall of theblock is made the deformation or contractio'nifotthe .blocl; resulting fromthe load becomes less, and thisdecrease in the deformation 'actually'results in a far greater load on theblockwhen' the 'c'oilfis 1 comma BLOCK f; I

Blodgett, Worcester, Mass, assignor to on Company, .Worcester,

of Massachusetts February 20, 1s 2','serar1-1o. 431,663: 8 Claims. crate -rs 123000 msyfsq in, whereas if the radial deforma tion of the block during 'coil formation were .0 l0

the radial pressure would be only 2000 lbs./sq.in.

' loading of 'the block.-"

has been spun;

.-- It isaccordingly one'objeot' of the invention to provide" a block adapted" for'the winding of metal strip' thereonla-t high tension without over-- I further object of the invention to provide a blockfadaptedfor the windin'g of metal strip the'reon and so" constructed that'it'rnay be easily Withdrawn from the coil afterthe latter lt 'is-af f u rther object omhe' invention t em-i videa block adaptedffor the winding of 'metal strip-thereonat high tension-and so constructed that the stresses will be distributed'much more uniformly throughout the block than with prior I devices. r

thicker in order to", carry the load safely, 4o.

completed. In other words, the more the block yields during the formation of the coil, the less the pressure will be 'on the outside of the block,

1 It i s a furthenobject of the invention to provide a block adapted "for the winding of metal strip thereon at high tension" and so-construc'ted that it will yield radially, during the'formation of the coil, to ac'onsider'ably greater .eXtent than t blocks ofprior construction utilizing substantially the sameamount of material;

With these; and other objects in view, as'will be apparent to-those skilled in the art, theinvention resides in the combination of parts set forth in the specificationand covered by the :claims appended hereto. a

-Referring to the drawing illustrating one embodiment of the invention and in which like, reference numerals; indicate like parts, 1'

Fig. 1 is aperspective view of ablock andits supporting arbor, with the; parts disassembled in the axial direction 'to'showtheir construction to better':advantage; a a

"(Fig.2 is a perspective-viewer the inventionin operation duringthe-formation' of acoil; I 11 l Fig. is an enlarged section on the line 3- 3 o-Fig.2;'and:

,. liig. 4, is a sectional viewshowingthe bloch'and coll. mounted on a spinning table.

The embodiment illustrated comprises agzhorh.

zontal rotatable: overhung .arbor l0 which; may

, bersupport'ed and :driven by anygsuitable and since the inner convolutions of the coil will to a considerable extent resist and supportthe radially inward pressure of "the outer convolu-j tions. This will be obvious when it is realized that a coil can be wound tightly upon ablocl; of

the well-known collapsible type, 'and' upon com-j. pletion of the coil the block can be collapsed leav-v ing the coil entirely self-supporting, withall pressure removed from the block. Nor'-is1this* reduc-- tion of pressure resulting-from deformation of the block a minor matter; In one particular instance calculations indicated that if the block were entirely incompressible the radial pressure thereon upon completion of the coil would be wellknownrmeans. 'Thisarboris preferably of square or other non-circular cross-section; r and I it serves :as 'asupportin'g and; driving means :for

the block which forms 1 the. subject, matter of the present'iinvention. n i I "In accordancexwithithe preferredform of the invention this block comprises a plurality of-,sep-. arable parts "which cantbe assembled? telescopicallyklin theaxial direction. 'The; outermost of;

these partsispreferablyshaped toprovide a con-;

. tinuous 'smooth outer cylindrical,surfaceabout whichithe metal strip'tmay be woundnintoa coil;

Radial clearancesaretprovided between thejparts, I

and these clearances; 'while small; are ;neyerthe compressive loading to the outermost part of the block, this part will receive all of this loading until it has been deformed enough to take next part, whereupon this ne gt part will assume a portion of the load which'is-added there;

after. tVhen the two outer parts have been ,de-

formed enough to take up the radial clearance which surrounds the thirdi part'.(if ,one be pro videcl), any subsequent loading will then be divided among all three parts of the block. 'Upon m le o o heoi i the blo k. iss q rectly proportioned,;the partsthereof willfibe stressed a e n orml hanwou dme the case with a sin ie blockiof he ame. hic ne s, and

the calculations, it will be assumed that the inher sleeve is one inch thick and without ribs.

Ordinarily, in calculating the deformation and stresses in" hollow cylinders {subjected to external radial pressure, the cylinder is treated as thinwalled if the ratio of thickness to outside diame- I V ter is less than 1/10, and as thick-walled if this up the radial clearance between itself andthe t e a de orm t q tw lb muc eater, han

w h. a in ei ce locs, stresses will be well within the elas tic limiter he. ma e alr o that he ofisinah learanceswifl be; re tor d when he oad n sn emoved b jthe in it he 9. .1 nd; h a tsl anleasily be. w hdrawuone at av met iomthe coil. sin e the weight of each individual part is much less an he Weight 0ft in e-piece. blo slthewit e i eat y 4: ita em n he ar cu a l l odimen i lustrated the lo s m dam hr e i e nclud n animn r mb I 1.. n in rm d ate mem er 2-.-.. and

urth rmore. al

an outer member l4. All three of these members are in the formof cylindrical sleeves. The inner member ll is provided withinternal ribs 15 shaped to provide asquareybore or opening l6,

adapted tofit the, arbor H],- with ample clearance for easy withdrawal therefrom, This memher, I] is shown slightly longer, than the other sleeves, and at its. outer end it i provided with an inwardly, extending, annular flange l 8,; wh facilitates, the. uneendingc of the, 'loaded blocl;,; as willbeexplained hereinafter. At its; other end the member ll isprovidedwithapainohdiamet: rically opposite radially projectinglugs, l'9;;,(o ne only being visible in Fig; l), Atgas'se mbly. these lugs i Senternotches. 20., in .thesinner end; of; each sleeve 12 and'llllto provide,a ,torquertransnritting connection between the partspf, the block ,In the case of blocks large enough ,to, make .jweight reduction an important matter; cIcprie'fer;to,v use a metal or metallic alloy of relativelylowspecific gravity and highstrengthi. One-sushi alloy-sis Duralumin,; which contains, 4.0%,; copper; 5%;

manganese, .5.%1 magnesium; and the balance aluminum. This alloy when properly heat treated has an elastic: limit of 40900 lbs/sq, in., a Youngs modulusof; 10;Q0l0,00i),,and ;a ,Poissons ratio of .33; 1

Radial clearancesare' provided betweenlthel intermediate member 12 al'ld'ilh members I hand i 4 respectively, these clearances depending. upon the size and material of the..:block.; Bycway of example, let us suppose that'we are. toconstruct a block with an outside/diameter: of 16;ii1chesf for the coiling of metal strip 9ri'nchesiwide at high tension. If such av block .is/ madeof three telescoping sleeves of Duralumin, each with a' radialthickness of one inch, thewleight, preach; sleeve Will be small enough to permit aeasy handling thereof by one man. Since theribs I5 have the efie'ct of strengthening theinner. sleeve H this sleeve can be somewhat 1 less than one. inch,

in thickness and still havegthe SameLstrengthasi an unribbed sleeve one inch thick. Toasimplify, 75,

he e;

ratiois greater than 1/10. Different formulas aetheeraeial-determine;

R..= enmen ediuaw S=the tangential stress Applyingthis formulato the outer-sleeve l4, and afs'surfiihg"that 'this'paift: is made of Dur'alan that3Q,00(l is arasoiiable maximum j.. 51' 23oli n aomoq Applyingthe same-formula theintermediate pp n thesame form la"to-lthetinnehs e ye t, we h ve From 951" A ie rq sn. a T 12 1 et v dec l tween r endjthe ntermedia e sleev nd,

pr; 9 1? 9i 9165'.'; .qaliL et ee i h term iate 'wii llt iis't nstmcr xi e im e w s, 1 w ll betak nfb'y le .fi.. 9 t stre se n. tee-sev al eevesw l di he. inne lee e meam li-lQi-ms ah ir -q s idc'diametep LOIIBI i i hfi's; For (a .this .15 p we haye the Whe e. l aih iiem ti elel ,l d n where Substituting the ,known, values for the thickwalled Duralumin cylinder, using 30,000 as a rearadial pressure safely T= the wall t ickness, and the other elements are as et forth above.

Applying this formula to the inner sleeve I I, We obtain Applying the formula to the intermediate sleeve l2, we obtain 30,000 1 -4615 Applying the formula to the outer sleeve 14, we obtain I 30,000Xl P -=4000 Under full load conditions, the clearances between the sleeves disappear, and the sleeves II and I2 serve to support the sleeves l2 and I4 I respectively. Hence the strength of the multisleeve block is cumulative, and we have as the safe limit of external pressure for the assembled block In calculating the value of the radial pressure to which a thick-walled cylinder can be safely subjected, we have Formula 3 set forth above. Applying this to a single block with an outside diameter of 16 inches and a thickness of 3 inches, we obtain Thus the single piece block can be safely subjected to an external pressure of only 9140 lbs. sq. in., as compared with 14,069 lbs/sq. in. for the three-piece block, which fact alone would permit the winding of strip at a much higher tension on the three-piece block. However, this is by no means the entire story for, as we have already seen, the single piece block will contract only .0286" in diameter before it is fully loaded, whereon the outside of the sleeve yll. in'known manner.

Ordinarilygthis .metal ;,will be delivered to the blockfrom; a rolling mill 22 (Fig; 2). As the formation of the coilproceeds, the radial pressure on the outside of the block will increase, forcing theouter sleeve Hi to contract against the intermediate sleeve 12, and eventually fore ing the intermediate sleeve to contract, against the'inner. sleeve H. When the coil is completed, the loadedblock will be withdrawn from the arbor and up-ended, preferablyby-means of an g apparatus -25 (Fig. 4) having fingersifi adapted I so as the three-piece block will contract .045 in diameter. This increased contraction or yielding has a very pronounced effect in reducing the pressure between the coil and the block, and therefore makes it possibleto employ a still greater tensionon the strip. For the same reasons, it will be clear that it is possible to wind strip at a given tension into a coil of much greater outside diameter with the three-piece block than with the single-piece block.

It will now be apparent that in the operation of the invention the telescopically-assembled block will be mounted on the arbor l0, which will be driven by suitable means. The lugs l9, by engagement with the notches 20, will cause the three parts of the block to rotate in unison. A coil C of strip metal will be wound under tension to engage the 1 flange l8. For a complete disclosure of the apparatus 25 reference may be had to the patentto Eddy et a1. No.;2,256,97, 5, granted Sept. 23, 1941. This patented apparatus. can be used to spin: the coil and loosen the convolutions thereof, whichflwillrelease all pressure from the sleeves H, l2 and 14. Since thesesle'eves were not stressed beyond the elasticdimit they will resume their original dimensions, the original clearances-will be. restored, and the sleeves can be lifted one at. a time from the coil. Since each sleeve'represents only a fraction of the entire weight of the-block, this lifting is a comparatively easy matter- ,It,wi11 be understood that. at. least two blocks should be provided, so that one coil can be spun while the next coil is being wound.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: a

1. A rotatable coiling block comprising a metal inner member, a metal outer member surrounding the inner member with a slight radial clearance between said members, the outer member having a continuous smooth outer cylindrical surface about which metal strip may be wound un der tension to form a coil, and means to transmit torque from one of said members to the other.

2. A rotatable'coiling block comprising a metal inner member and a metal outer member surrounding the inner member with a slight radial clearance between said members, the outer member having a continuous smooth outer cylindrical surface about which metal strip may be wound under tension to form a coil, the members being so proportioned that as the outer member contracts by reason of the radial compression load applied thereto during the formation oftho coil the said clearance will disappear before the outer member is stressed to its elastic limit in the tangential direction.

3. A rotatable coiling block comprising a met a1 inner member and a metal outer member surrounding the inner member to provide a continuous smooth outer cylindrical surface about which metal strip may be wound under tension to form a coil, there being a radial clearance between said members such that as the radial compression load applied to the outer member during the formation of the coil increases, the said clearance will disappear and both members will reach the safe limit of tangential compressive stress at substantially the same time.

4. A rotatable coiling block comprising a metal inner member and a metal outer member arranged to be assembled telescopically in the axial direction, the outer member having a continuous smooth outer cylindrical surface about which metal strip may be wound under tension to form a coil, there being a radial clearance between said members such that as the outer pression loadapplied thereto-during the: forma tion of thecoil kthe said clearance willidisappear ing a radial'clearancebetween-the-sleeves such that as the coil increases in diameter: andapplies an increased radialcompression loadmo: the block the clearancewvill disappear beforeanyzof the sleeves is 'over stressed iii-the tangentiat idi rection. r i I c 6.. A rotatable coiling block comprising at least three cylindrical; metalsleeves arranged to: be assembled telescopically in: the axial. direction; the outer sleeve having a continuoussmoothiouter cylindrical surface about whiolr metal istriprmay be: wounduunders 'tension'hto: forms a coil} there being radial .clearances=. between adj acentsleevies suolitthat as the coil increases rinwdiameter rand applies an: increased-radial: compression: loadi Etc the-bloclmhe clearances will all disappear-before 25 l A 'rot'atabl coillng b1ook comp isi-ng a plural'ity': 0! Instal members arran ged to' be assembid telescopicai lydn-atheaxial directional-1d- :providing a continuous smooth-outer cylindrical surface about which metal strip may be wound into a coih; the outermem'ber=having a 'notchin one end? and the innermember-having- "a lug th'ereon which' -ente'rythe notch atasmemblv to: prevent relative rotation of the members.

8& A-rotlatable' coilingblock comprising a-metal innenmemb'er, and 'aimetal outer member in the form of a cylindricalsleeve surrounding the-inner member with a slight radial clearance between said members, the outer-member having a continuous smooth outer cylindrical surface about which metal, strip may bewou'nd under tension to form a coi1,"the thicknesso'f'the outer member being less than one tenthitsout'side diameter, and-the members beingsoproportioned that-as the outer member contracts by reason of the radial compression loadrrapplied thereto during the formation oftlie coil/the said clearance will disappearhbefore the outer member is stressed to its elastic limit in the tangential direction;

ALBERT GUBLODGETT.

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