US1833747A - Method of making annular members - Google Patents

Description

' NbvQ24, 1931; F. A. HAUGHTON METHOD OF MAKING ANNULAR MEMBERS Fi-led'Oct. 31, 1928 4 Figl.

by r A Has Attorney bending.

Patented Nov. 24,1931

UNITED STATES PATENT OFFICE FRANK A. HAUGH'ION', O1 SCHENECTADY, NEW YORK, ABSIGNOB 1'0 GENERAL-EEG I i TBIC COMPANY, ACORPORATION 0F NEW-YORK name!) 01' mxme muumm armaments:

Application filed October 31 1928. Serial No. 316,280.

My invention relates to a method of making annular members by rolling slabs or plates of material into annular form, which are of general utility, but are particularly useful in making dynamo-electric machine frames and cylindrical pressure vessels.

- It has been the ractice heretof re in making annular mem are out of slabs or plates of steel to form them in bending rolls. These rolls consist of two stationary rolls arranged side by side and spaced apart-and a vertically adjustable roll usually arranged directly above the space between the stationary rolls.

Ordinarily the slab or plate of material has been first formed, adjacent the ends, of the curvature required in the completed. annular member because these portions could not be formed with this curvature by means of the rolls. This isdue to the fact that in rolling the slab the maximum bending stress therein is approximately midway between the stationary rolls and decreases in direct proportion to thedistance toward the end thereof, so that when the portion adjacent the end of, the slab is just enterin or just leaving the rolls, bending therein ta es place almost entirely at a point spaced from the end thereof a distance approximately equal to half of the spacing of the stationary rolls, and practically not at all between this point and the end of the slab. In the case of, thick slabs or plates the portions adjacent the ends have, therefore, been formed in a suitable press, and if they were being worked hot it was necessary to reheat them after the forming operation before they could be rolled into annular form. In the case of thin slabs or plates it has been the practice to form the portions adjacent the ends of the desired I curvature by placing the slabs or plates in the rolls with the end portion projecting a small amount beyond one of the lower rolls and bend the same downwardly as desired by means of a sledge hammer. This necessitated removing the slab or. plate from the rolls and turning the same over, as

the 'rol s bend the ends of the slab or plate upwardly during the rolling operation.

The object of my invention is to carry out a method of making an annular member such tant when hot slabs are that the slab or plate can be rolled into annu lar form entirely by the use of the rolls and without any interruption in the process of manufacture. This is imporp'articularl into aneing r01 nular form as the interruption caused b the independent preliminary operation of orming the ends, necessitates reheating of the slab or plate, in many cases,.before the rolling operation can be continued. I carry out this method by forming the portions adjacent the ends of-the slab or plate of varying cross-section such that they can be given uniform curvature in the bending rolls, and then roll the slab or plate into annular form with the ends engaging each other.-

My invention will be more fully set forth in the following description referring tothe accompanying drawings, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In the drawings Fig. 1 is a plan view of a slab having the ends formed inaccordance with my invention; Fig. 2 is a diagrammatic view of the bendingrolls showing the end of the slab arranged therein; Fig. 3 is a view similar to'Fig.2 showing the rolls adjusted to bend the slab; Fig. 4 is a perspective View of the completed annular member, and Flg. 5 is aperspective view of a plate rolled into annular form in accordance'with my invent-ion, such as would be us ful in making a container or pressure vessel. 1

Referring to the drawings, the rolls which I employ in forming slabs or plates into annular members are commonly known as pyramid rolls and comprise two rolls 10 and 10a which are arranged side by side and supported in fixed relation to each other, and a vertically adjustable roll 11 which is arran ed directly above the space between the stationary rolls. In carryin out 111 method of making an annular 'mem er, I rst form the ends of the slab 12 so that they can be bentwith uniform curvature in the bending rolls without twisting the ends of the slab. I obtain uniform curvature of the port bn adjacent the ends of the .slab by forming them of a cross-sectional area which varies from the ends to a point spaced from the ends thereof a distance approximately which distance is half the distance 1) between the rolls as shown in-Fig. 2. By

this construction when the slab is placed in the upper roll is adjusted as shown in Fig;

the rolls with one extremity .15 above the center of'the bottom roll 10 as in Fig. 2 and 3 to bend the slab 12,'the maximum bending moment exerted upon the slab will be directly under the 'axis -of the upper roll 11 and decrease in proportion in both directions along the slab as the points ofcontact with the two lower rolls is approached. -Owing, however,

a to the width of the slab being reduced in m between the said point of maximumbending.

proportion as the end is approached commencing from the point of maximum bending moment, any cross section of the slab throughout this'portion isequally stressed by downward adjustment of the upper roll 11' 'andconsequently will bend equally throughout this ortion. Coincident with the downward a justment of the 11 per roll 11 practicallyno bending will ta e place moment and the point ofcontact with the lower roll 10a for the reason that the slab is of constant width throughout this portion and consequently the stress in any cross sec ends thereof. are.

tion of thisportion becomes less in proportion as the point of. contact with roll 10a is a proached.

- In. ordergto' preyent twisting of slab 12, whenthe portion adjacent the end thereof passes into out -of the rolls, .1 vary the cross-sectional area in such manner'that the mmetri'cal with respect to theloiifitudina axis of the slab. As shown in Fig. 1, -I do this by forming a -V t-hereo. tion 15,

sha d' notch 18 in one end so as to rovide pro ections 14'on" both' sides of the s ab, app 'x v y same distance from the axis of theslab, so

- that they they will balance each 'other and there will be no tendency to twist these por-f tions when they pass into and out of the rolls. L

Moreover, there is no tendency for the. V-

' beent the joint when the cylindrical vessel was subat the resultant of the forces actingon each of the portions'is the shaped portion 15 of the slab. to twist when it passes into and out of the rolls, as the resultant of the forces exerted thereon by the rolls is on the longitudinal axis of theslab.

After forming the endsof the slab 12 in this manner, I place one endthereof between the rolls 10, 10a and 11, as shown in Fig. 2, and lower roll 11 to bend the slab as shown in Fig. 3. .I their cause the rolls to be rotated in the direction indicated by the arrows in- .Fig. 3 and bend the slab throughout its length to the curvature corresponding to the amount of adjustment of the u per roll '11. When the other end of the sla by reason of rotating the rolls, has reached the point of contact with roll 10a I make a further downward adjustment of then per roll 11 causing the portion of the slab romthe point of maximum bending moment tothis end to bend uniformly throughout due to its uniformly-decreasing efi'ective width at the portions'14, Figs. 1 and 4. I then rotate the rolls in the opposite direction and im art afurther degree of'curvature to the-s ab. I repeat this cycle'as often as necessary until the slab is formed into a complete circle and the end 15 conforms to the notch-.13, and I then revolve the annular memberin the rolls severalv times with only a very. slight downward ad'ustment of the roll ll thereby obtaining a igh' degree of accuracy in true circular form and causing the portion 15 to be firmlyseated in the notch. 13. IIcan do this without interruption on account of the overlapp'i I then remove'the annular member from the rolls, which is now in the form'shown-in Fig.-

4 and weld the portion 15 to the portions 14.

' In making cylindrical containers or pressure vessels'one of the objections to the use of longitudinally extending welded joint has e frequent localization vof stresses at jected to pressure. This has been due to the fact that the side walls of the vessels have not 7 been of true circular form, so that when pressure has beenapplied thereto the side walls tended to assume true circular form which subjected the joints to a combifiedlbending and tension stress. and often caused them to fail. In accordance-with my method this ob- --jection to a welded joint in a vessel of this kind has been overcome by making the joint of such form that localization of stresses can occur only over a small I rtion of the joint,

and rollin a plate constituting the'cylindri-' cal wall o the vessel into true circular formso that the wall is subjected-only to tension stress. I do this by rolling a plate into true circular form in bending ro ls of the arrangement diagrammatically shown in Fig. 2, and

forming the jointof interfitting portions so thatthe welded portion of a lon itudinal sect on 0f the joint includes a sma proportion ends which avoids an abru t open gap at t e ends into which each of t e rolls would. jolt in passing;

no I

thereof. Forming the joint of interfitting portions also enables me to roll the plate into annular form with uniform curvature throughout its length entirely by. the use of bending rolls, as the portions adjacent the V ends are formed of varying cross-section such curvature as that the rolls give them the same This method the main portion of the plate.

. is carried out in the present instance by first 1 be given the curvature forming one end of a plate 16 with a plurality of notches of a depth approximately length, and adapted to conform to the notches in the completed annular member. In this way the portlons adj aceut the ends of the plate vary in cross-section so that they can desired in the bending rolls without removing the plate from the rolls during the process of manufacture, and without twisting the ends of the plate. By forming the projections 18 and notches 17 in the ends of the plate in this way, it Wlll be seenthat I obtain greater strength of the joint connecting them together, which is welded in the completed annular member,

than in a construction in which two straight abutting edgesare welded together in accordance with the usual practice, because of the greater length of the weld and the-small proportion of the weld in any longitudinal section of the 'oint. After forming the notches, and pro ections in the ends of the plate I roll the same into annular form shown in Fig. 5, in

is'rolled in annular form as above described, and the ends thereof are welded together.

Modifications of the particular method which I have disclosed will occur to those skilled in the art, so that I do not'desire my invention to be limited to the method set forth, except as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States. is:

1. The method of making-an annular member comprisingforming a portion adjacent each of the ends of a slab of material formly varying cross-section throughout their length so that they can be given uniform curvature in bending rolls, and rolling the slab in a direction from one of the formed ends thereof toward the other into annular form with the ends engaging each other.

2. The method of making an annular member comprising making a' portion adjacent one end of a slab of varying cross-section throughout their length the same mannerthat the slab 12 of unimaterial of uniformly by forming a V-s'hapednotch which is substantially symmetrical with respect to thelongitudinal axis ofthe slab' and the other end with a V- haped portion uniformly varying in cross-section throughout its length and substantially symmetrical with respect to the longitudinal axis of the slab which is adapted to conform to the notch, and rolling the slab. in a direction from one of the formed ends thereof toward the other into annular form with the portion conforming to the notch.

' 3. The method of making an annular men ber comprising making a ortion adjacent one end of a slab of material of uniforml varying cross-section throughout its length by forming a notch which is substantially symmetrical with res ct to the longitudinal axis ofthe slab an I the other end with a portion of uniformly'varying cross-section throughout its length" and substantially symmetrical with of theislab wh is adapted to conform to the notch, rolling the-slab in' adirection from formed ends thereof toward the one of the 7 other into annular form; with the portion" conforming to the notch,and securingthe ends ofthe slab together.

.4. The method of making an annular member comprising making a rtion adjacent one end of a slab of material of uniformly varying cross-section throughout its len by forming a V-shaped notch which is. substantially s mmetrical with respect to the longitudina axis of the. slab and the other end'with a V-shap va'ryin cross-section throughout its len and su stantially symmetrical with we to the longitudinal axis of the slab whi'c is adapted to conform to the notch, rolling the slab in-a direction from one of the formed ends thereof toward the other into annular form ,with the ortion conforming to the notlclh,.and'secur1ng the ends of the slab tot er. 5. The method of making an annular member comprising making a ortion adjacent one end of a slab of materlal of uniforml varying cross-section throughout its lengt by forming a V-shaped notch which is substantially symmetrical with respect to the longitudinal axis of the slab and the'other endwitha V-sha d portion ofuniformlyJ varying cross sect1on throughout its lengt substantially symmetrical with respect to the i v. In

thereof toward the ther into annular form with the portion conforming to the notch, and welding the ends of the slab together.

6. The method'of making an annular member which comprises forming one end slab of material with a V-shap'ed'notch of'a depth equal to half the distance between the axes of relatively fixed bending rolls and ed portion of uniformlyrespect to the longitudinal axis 7 I substantial] symmetrical with respect to the A longitndina axis oi the slab formin' the other end of the slab with a il sha. por-: tion of glen equal-to half the distance between the re tively fixed rolls and substantially symmetrical with respect to the longitutlinll axis of the slab which is adapted to conformto the notch, and rolling the slab into annular form with the portion conformtothe notch.

witness whereof, I have hereunto set my hand'this 30th da of October, 1928. FR N-K A. HAUGHTON.

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