US1468692A - Method of making boiler headers - Google Patents

Description

Sept. 25, 11923. $1,418,692

J. F. L. BAKER METHOD OF MAKING BOILER HEADERS Filed April 25 1921 INVENTO/t ATTORNEY Patented Sept 255, i923;

J'GHN F. L. BAKER, (3F SAGIIIAVT IEECH WWI ii ,Applicaticn filed s in 25,-

T 0 all whom it may concern Be it known that I, JOHN F. L. BAKER, a citizen of the United States, residing-at Saginaw, in the county of Saginaw and State of Michigan, have invented certain new and useful Improvements in Methods of Making Boiler Headers;'and' I do hereby declare the following to be a full, clear, and exact description of; the irWentio-n such as Will enable others skilled in the art to which itappertains to'make andiise the same.

This invention relates to headers for Water tube boilers andthe like and the objects of my improvement are, to siinplitv-andiin' prove the method of making Wide headers, that is to say; headers, the platesor" Which are so far separated as to form a Water space, or steam space of considerableWidth sa -ten inches or Wider.

My improvement relates more particularly to the method WhichI employ inforining or fabricating the flanged plates consti-y tutlng the tube-sheets of 'theheader, and to the forming-dies by-Which the; method is carried out ini-practice.

T It has heretofore been customary in Water tube boiler manufacturing practice to flange the two sheets formingwthe walls of the header or waterleg; and toback one of the'he'ads into'the other, riveting orcalk ingthe'outer edge ofthe joint so. formed;

' Formerly the edges of the header plates were bent to form side and end fliinges, and

the corner produced'by the junction of the "body of the plate with the sideiand end flanges Was then heated and-pressed into shapebyzone operation ofa forming die.

It has, however/beenimpossible by the above mentioned' operation to produce; a satisfactory-flanged corner on a heavy plate; say, iflve-eighths inch thiclr andhaving a flange over four, inches indepth; because the junction oftheflan'ges att-he corners of the plate couldnot be satisfactorily formed Withdeeperfiange's, on, account of he tend: enc v of thegsurplus material atthe corners to. fold sand crinkle and i-n c some places to stretch and 'become thing; T

The tube sheets of headershaving water spaces ten' inche's'oryinore' in width require .Wide flanges, jsayeithirteen to a fifteen inches deep' and consequently the tormermethod is not. adequate for the manufacture of headers having-very deep flanges that are bent to. radii of; say, six inches and over;

Such a largeradius flange construction is shown in my lPatent isiOdEZi.

By my present improved method 1 produce headers cm thick mat eio'hths inch or thicken and l or six inches and over, the unction o the flanges formed ers are set forth in myco-pesdin applies tionabove referred to. ldy present method f forming the flahged corners iv ting or Welding, and While mainta A normal thickness of metal, is particular- Well adapted to the forming of lOllQj-lt us, deep hanged header plates, because the long;- radius flanges can readily be formed "at the corners into an integral, long-radius spherical. heel; and sucha heel utilizes the greatest amount possible of the plate material at the corner, andsense uently requires a minimum amount of material to be pressed or flowed to maintain the required uniform thickness.

It is essential in boiler work this character that the final thickness formed or flanged plates shall be u iform. That is to say, the thickness at one point of the spherical corner shall be the same at thickness at any point on the i e, or any point on the body of the plate. mv improved method 1 produce flanged and the formed header plates of uniform thickness at the flanges and cor and prevent the permanentstretching or, the meter l and the formation oi thin spots.

sphericaland of uniform thickness, is illustrated' in the accompanying drawings, in

, lines.

Fig. 3 is a fragmentary plan View showing a corner of a tube sheet trimmed preparatory to flanging, the part removed by trimming being indicated by dotted lines.

Fig. 4: is a fragmentary plan view showing a corner of a flanged tube sheet.

Fig. 5 is a perspective view, showing the corner of a tube sheet as it appears after the side edges of the sheet are flanged, one side edge shownbetween the dies of a flanging press. r

Fig. 6 is a side elevation of a pair of dies with a plate between, the edges of which have been flanged as in Fig. 5., and the projecting cornerin place for the second or main corner-forming operation, the die plunger shown in its raised position. I

'Fig. 7 is a similar View after the die plunger has descended, the plunger in this view being shown in verticalsection.

Fig. 8 is a top plan View of the plunger shown in Fig. 7.

Fig. 9 is anelevation of the-working face of the die plunger.

Fig. 10" is a horizontal section on the line 10-10 of Fig. 9.

Fig. ll'is a similar section on thedine 11-11015 Fig. 9.

Fig. 12 is an enlarged fragmentary section throughthe plateshown in Fig. 7, showing the increased thiclmess of the edge of the plate at the extremityof the corner after performing the second forming operation indicatedin Fig. 7.

' Fig. 13 is a side view of the diesused for the third or final flanging step ofmy method,

the plate being shown in the die in the con dition in which it was removed from the second fianging step illustrated in Fig. 7, the die plunger of Fig. 13 being in its raised position.

Fig. 14 is apart sectional side'elevatio'n of the parts shown in Fig. '13, with the plunger down, completingthe fonnation"of the top flange of the header.

In employing my method, I first take a steel plate 1 o'f'propersize andthie'lrness,say, five-eighths inch, trimming each "corner '2, to a somewhat circular shape.

The rounded corner is then heated and .slightlyformed by being bent downwardin the roughing die illustratedin -Fig. 7

The side edge 3 and edge 1 of the plate are then successively heated and flanged irh a suitable press 5, as indicated insFi'g; :5, to produce a fiange of approximatelysix inch up -to,--say, ififteeninches. r V I,

After the edges -3 .and;4 ofe-theplate have been flanged, each. 'corner' shows an .outwardly projecting scoop-shaped or hood like part 6, as shown in Figs. 5 and6, and it is from these scoop-shaped corner projections that the final large-radius spherical heel or, corner of the header is-afterward formed;

The next step is to reheat the scoopplate at the outer edge'lO of f3. corner so orgreater radius and of any desired depth 7 shaped corner'6 and to'place the hot plate I formed discloses that the outwardly project:

ing part of the plate is-thickerby a pproxi mately one-eighth inch than the fthickness of the heel 8, orof the body-1, of'th'e plate. If

the plate isjfive-eighths inch thick, itwill be'found afterthe heel-forming operationiof f Fig. 7, that the-'outer 'edge 10 of the plate,

atthe orne ds approximately threesfourths inch thick, and that' thisthickness gradually decreases from theextremeiedgeto.the normal thickness of about :fi've-eighths. inch at thesp'herical part :or heel i 8,1sh ow-ingi that the heated surplus material in the plateat the corner has been'oaused, by the pressure. of. the heel-forming." die, to 'fiow' into the outer part 10 of the corner. lip. By "the term-surplus material, I aneanithe' amount of: metal which'is in excess of the amount irequired to form "a sphenical'cornerfand flange-equal ans in thickness to the thicknese .or'fithe plate. 1

calheel and flange than is; :present :in-.ithe corner portion ofthe flati trimmedplate. 1

For many years it 'has'been "demonstrated distontingitheimetal at. the corner can only be avoided-wit :sh'allow flanges. are "formed;

This surplus :is'rpresent' because less metal is required :to be present inethe finishe'd spheri'- Such crinlc li-ng is inevitable'withwa singleoperation die "when "deep fiangeszareigiormed, because a singlei die is'iincapabl'e of: both forming theeorner and-l ifforcingfmetal to flow into; proper.positionwinlfthegrheel iand 1 V Lth'erefora cfiorm-the-iheel:'8- andionlypan tially form the flange-'walls}3,4eof thet'corner in" the die operation justldescrihed, and: :em-

ploy. a further :orithird step to: complete the corner forming o eration. Imthisr third step, I reheat thecorner:- of the plate-and place the partly formed corner under a Vertically movable finishing die 11, of partlycylindrical shape, as in Figs. 13 and 14. This die 11 completes the straightening or bendin to ninet de rees ofthe flan e Fi a b b. 7 to 12, as it was left by the heel-forming die 7 at an angle oi approximately sixty 'degrees from the. plane of the plate. This finishing die 11 is so hacked or supported and held at a fixed distance from the die block and plate by the guide 12 that it can not spring. It, therefore, produces a finished flange of correct and uniform thickness, say, flye eighths inch, and distributes the thick metal between edge 10 and the heel 8 lei'tby the previous operation, in such manner that partoi the metal will flow laterally as indicated by the .arrow in Fig-.14 to make up the desired thickness of the side Walls of the flanges 8 and a and the other part of the surplus metal will flow clownward, and will form a slightly; projecting lip 13, which lip is found to be of considerably greater thickness than the thickness of the plate. The edge of this lip can later be trimmed ofl' flush with the side flanges 3 and 4,

Notwithstanding the fact that formermethods which I have herein. previously described, can be depended upon to produce satisfactory flanged. headers having flanges of not over, say, four inches in depth, it is a demonstrated fact that for headers requiring the use of heavy flanges or" relatively great depth, say, from four to fifteen inches, the former flanging methods are not practicable on account of the amount of'material in the plate at the corner. My present improvement, however, entirely overcomes the difliculties of the former method and renders it perfectly feasible to properly form flanged corners of great depth.

Having thus described my invention, what 1 claim and desire to secureby Letters Patcut is:

1. The herein described method of forming deep-flanged headers comprising trimming the corners of the header plate, to

approximately circular form, heating a corner and pressing it to bend the edges at the corner slightly downwardly, heating the side edges or" the plate and flanging them to a large radius and thereby forming an elongated scoop-shaped projection at each corner, reheating and pressing said projection to form a practically spherical heel of the same radius as the flange radius, bending the projecting part of the scoop-shaped corner downwardly to an angle of approximately sixty degrees from the plane or the plate, re-heating the corner and pressing said projection into a position at right angles to the plane of the plate while simultaneously forcing a portion of the surplus metal of said projection to flow laterally into the flanges, to thereby restore said parts to uniform thickness.

2. The herein described method'of forming deep flanged headers comprising trimming corners of the header plate to approximately circular form, heating the side edges of the plate and flanging them to a largeradius, thereby forming an elongated scoop-shaped project-ion at each corner, re-heating and pressing said projection to form a spherical heel of the same radius as the flange radius, re-heating the corner and pressing said projection into a position at right angle to the plane of the plate while simultaneously forcing a portion of the surplus metal of said projection to flow laterally into the flanges to thereby restore said parts to uniform thickness.

3. The herein described method of forming deep flanged headers comprising trimming the corners of the header plate to approximately circular form, bending the side edges of the plate to a large radius, thereby forming an elongated scoop-shaped projection at each corner, heating and press ing said projection to form an approximately spherical heel of approximately the same radius as the flange radius, re-heating the corner and pressing said projection into a position at right angle to the plane of the plate.

4c. The herein described method of forming deep flanged headers comprising trimming the corners of the header plate to approximately circular iorm, bending the side edges of the plate to a large radius, thereby forming an elongated scoop-shaped projection at ach corner, heating and pressing said projection to form an approximately spherical heel of approximately the same radius as the flange radius, re-heating the corner and pressing said projection into a position at right angle to the plane of the plate while simultaneously forcing a portion of the surplus metal of said projection to flow into the flanges.

In testimony whereof, I aflix my signature.

JOHN F. L. BAKER.

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