US2515841A - Tube closing apparatus - Google Patents

Description

July 18, 1950 c, J, STUART 2,515,841

TUBE CLOSING APPARATUS Filed Dec. 16, 1943 3 Sheets-Sheet 1 mrmlaxm 5 AHHIIIIY Z v GI /42452:

ATTOENEYI).

J l 18; 1950 r c. J. STUART TUBE CLOSING APPARATUS 3 Sheets-Sheet 2 Filed Dec. 16 1943 I |NVENTOR cf/R2456 J. 570437- ATTORN EY6.

July 18, 1950 c. J. STUART TUBE CLOSING APPARATUS 3 Sheets-Sheet 3 Filed Dec. 16, 1943 I I l I I I I ass INVENTOR Qswexafi J 67-05%? ATTORNEYS.

Patented July 18, 1950 TUBE- QO 1 A L' TAK A'EUS.

Gharles J. Stuart, Fort Atkinson Wis, assiguoir m M e Bl tters Ma iiii sqoein er Fer-t Atkinson; Wis. co po ation t dnpl eatien Re enter 16, 1 e l' e. 153

(or. tissuesfilaims. 1 This invention relates to improvement-sin tube closing apparatus. I

It is the primary object of theinvention to provide means for achieving at least partial closing; oflthe end of a casing-which is already partiallyor completely closed at its opposite end, so that} it not feasible to have any supporting mandrel within thecasing' to assist in thefior-mation of the end closure It is important to the objectives of" thepresent inventiontha-t the fin ished workpresent a smoothsurface and uniform wall thickness; without irregularities or wrinkles despite the fact that itis desirablethatthe pressing operations thereon be performed at: atmospheric temperatures.

' More specifically, the invention proposes the partialolosing oi the end oi a tubular casing in a series or steps involving solely cold axial? pres,- sure, portions of the work acted upon in thesuocessive operations being annealed-between operations; By means of the invention- I am able to achieve at lowcost an ezgcellence of qualityheretofore deemed; impossible to obtain in a press method.

Other objects will be apparent to those skilled in the art upon analysis of'the following disclosure-or myinventioni lfn-the drawings:

Figure 1 is a.- diagrammatic View, showing-- par-- tially' side; elevation and partially'insect-ion an organization for performing the first operation of my tube closing method.

Figure 2 is a fragmentary view similartoFig-ure 1 showingthe apparatus used toperform a sec end: press operation;

Figure 3 is a view similar to Figure 1 and Figure 2, showing apparatus used" to perform a third press operation.

Figure 4 is a View similar to Figure l, showing Eragn ientar-ily apparatus used to perform a fin-- ishing operation;

Figure" 5 is an enlarged detail view, in section, of the'oompleted casing or container.

Figure 6 isa fragmentary view, partially in side elevation andgpartially'in vertical section, showing apparatus used for annealing intermediate the pressoper'ations; I

Figuro '7 is a view o f annealingapparatus as it appears in section, taken on: line l1" ot Figure 6.

Figure 8; is a view partially in; side elevation and: partiallyin section, showing a modified and preferredernbodiment of theproduot, with dotted lines illustrating successive positions or the i ormedencl portion;

figure 9 is a view similar to Figurel showing 2:: a modified apparatus which may be used for CIQS)? ing the end cit the casingshown inFigure 84 Figure; 1c is a. fragmentary detail showing the work and. thefirst forming die at the conclusion ofithaflrst iormingoperation.

Figure- 11 is.- aviewz similar to Figure 10, fragmentarily illustrating the work and the second forming die. upon. the conclusion of the second iorming operation.

Figure 12 is. a. view: partially in side elevation and partially in. transverse section, showing a modifled's-formiof: annealing apparatus. i

Bike-parts are identified: by. the samereference characters throughout the several views.

At the commencement of the operations-hereinaftentcbe describedi the work piece comprises a, deep drawn can or the form shown in. full lines in Elg ure l at 8. l he can or casing 8 may have a completely-closediend; as 2.12.80 in Figure 8, but the particular work piece here involved happens to, have opening. at 91in the bottom which is convexly' rounded, at. 10% where it joins the side llhe base, plate. is onithe press bed has a recess at- I52 into which. the bottomv end portion of the container 81 fits accurately. A stud l3 projecting upwardly trom the base plate at the center of the recess. [:2 enters. the aperture 9: in the work piece to provide additional positioning and sup port.

The side wall M of the work piece is fullyenclosed during the press operation to. be described. Blocks I55, slidable to and: from each other 1atmay, are concavely: recessed at Hi to fitv about the tubular wall 114 of the work piece so that, when soengaged, it cannot yiel'd'in any direction. The blocks. [5* are illustrated in. Figure 1 in a retracted position. They are advanced and retracted by fluid pressure, being supplied with arms. lz't' carrying the: pistons [.8 which are illustrated int dotted lines within cylinders I 9 with whichpipes 2G and 231s communicate for actuating thepistonsi and the: respective blocks selectively toward: their advanced or their retracted positions subject: to. the control of conventional valves (not shown). Either hydraulic or pneumatic pressure may be used. In either case, engagement and; release ofthe successive work pieces are virtually instantaneous.

Mounted on the press head 23'is a swaging die 2%. The-mount-.actual1y-used isresilient, the die being guided by pins 28 for limited movement against the compression of: springs 21-. This, however; is not essential to the result. The die has a cavity justsuiiflciently large toireceivethe the blocks I5, the press head 23 descends and '10 The work piece being tightly engaged between The upper and lower flames may be offset slightly as indicated in Figure 7 to accommodate the slight offset between the upper and lower portions of the inclined work piece.

When the work piece has been suitably annealed it is placed upon the same or a similar bed plate ll, engaged between clamping blocks and acted uponby another" die as shown in Figure 2. This die is mounted on the same or a similar press plate 23 and preferably has a pilot bar. 44, mounted centrally in the die 45. A socket 46 in the end of the pilot bar is arranged to enthe die 25 first receives and' then engages the tubular end of the work piece. As the end mar:

gin of the work piece, supported within the cylindrical wall surface 28, is contracted by the spherically rounded wall surface 29 with an inward *gage a boss I3 on the bed plate II.

The end of the pilot bar, in the lowest position of the die,

contacts *the bottom of the work piece to hold the. bottom flat. An upper portion of the bar camming action, the work piece is swaged in wardly to the form indicated by dotted lines at 3|.

The steel wall of the work piece has been caused by this first operation to greatly reduce its diameter at its upper end." Yet the work piece is so completely supported that there is no possibility of its buckling. Instead, the metal at the upper end of the wall is caused'to flow to its new form despite the fact that the operation is or may be performed at atmospheric temperatures. :The result is the production of a dome-like partial end closure with a central opening toward which the wall thickness has increased by the flow of the excess metal accruing from the reduction in diameter. I

The forming operation hardens tion of the work piece upon which the die acts. In practice the work piece hasbeen made .of steel, but the same hardening effect would be observed if the wall were of any other metals.

the wall por- Accordingly, before performing-any further operation upon the swaged wall, I prefer that the wall be annealed. This may convenientlyxbe done by the apparatus shown in Figures 6 and '7.

In the annealing apparatus, the work is preferably rolled by means of a conveyor througha heating zone in which it receives heat from both sides. Angle irons 32 and 33 provide a bed for conveyor chains 34 and 35, such chains bein connected by spacerbars 36. I v ,I

The bottom flange of the angle iron 32 provides a track upon which the 'convexlynrounded portions H! of the work pieces'B may roll. Another track is provided at 31 b'eneath intermediate portions of the work piece walls, leaving the end portions of such walls exposed for the annealing operation. A guide 38. extending longitudinally of the conveyor track 3215 abutted by the partially closed end of the work piece, whereby the work pieces are kept-in line. The inclination of the work pieces provides, a convenientand lower pipes 40 and 4| through which. jets of fuel, such as gas, duly ignited,-are*directed toward the work pieces as the latter are propelled between the pipes by the conveyor bars =36.

As the work pieces move between theupper and lower sets of flames they are rotated sotthat all portions of the hardened Wall surfaces become heated. In practice I have found that the-temperature to which they are heated isnot particularly critical. With the metal I have used a temperature of .1100 or-.1200 degrees F. is suit-r:

able.

serves as a limiting stop to define the minimum diameter to which the opening 41 in the work piece may be reduced during the continued closing of the upperend of the receptacle.

It will be noted that the confining and supporting blocks I5 are shouldered at 48, thereby being' provided with a generally cylindrical surface at 49. The die 45 is counterboredto providea complementary female cylindrical surface at 50. When the blocks l5 are closed upon the work piece and the die 45 descends, the female surface 50 willengage about the semi-circular portions 49 of the respective blocks 15' to hold such blocks securely against separation during the action of the die. This interlock between the die and the supporting blocks 15' is not essential but is desirable in any stage of the operation in which, as in that here illustrated, the axialpressure developed on the work piece is relatively high.

As in the case of the die 25 shown in Figure 1, die 45 is provided at 5| with a surface which confines the upper end of the work piece without exerting any reducing pressure thereon. Beyond the shoulder 52'theupper end of the socket of the-die is convex, as shown at '53, but in this particular operation the principal work done by the die is effected by the annular portion 54 thereof, which, acting on the inwardly formed and partially completed end wall 3|,- close to the maximum diameter of the convex portion, forces the entire end wall inwardly from the dotted line position shown in Figure 2 tothe full line position assumed by such end wall at 55. The remaining opening 41 will normally be substantially the diameter of the bar 44' carried by the die. Any excess of material in the work piece will engage the bar and be turned inwardly to'preclude the reduction of opening 41 below the desired predetermined cross section.

The work piece is now subjected to a third forming operation, represented in Figure 3. The work may again be annealed, but annealing has been found to be unnecessary for this operation.

Supported on the same or a similar base II the work piece is confined by supporting blocks l5 which are the same as, or similar to, those shown engaged about the upp r end of the work piece to provide support therefor. Itmerely comprises a block in which there is an annular. concave recess at 6| about an intermediate'boss-62 which is the approximate size of the opening- 41. When the die 60 engages the work piece the upper end portion 55 thereof extends convexlyr upwardly from; all sides of'the work piece. After the die 68- has acted? thereon, the end wall 6-31 extends corrvex'l'y upwardly from all sidesbut is then turned convexly downwardly and inwardly so that the opening 641 liesat' a materially lower level than the opening 41 left'by thepreceding operation, and is: below the highest portions of tlie convex-end wall 63'- of the receptacle.

In the apparatus showninliigure4 the receptacle is completed for the particular purposes now=in-rnind (a hand grenade casing) by mounting it in afixturewhichincludes abase plate 65 havingasemi-tubular supporting-wall as against which the-work piece i4 is seated; 'lfhe boss l3 engaged'in the central opening 9 in the bottom ofthe-work; pieceis like that previously used. A single-sliding block IS with aconcave work engaging; surface at is is movable to and from engagementwith the work piece for the clamping and release thereof. With the work piece clampedi in this fixture a: reamer or the like 6'! isusedto machine the margin of the upper wall of" the receptacle M at 68; about the" openin therein and to provide an; annular shoulder at W: The completed work piece is illustrated in Figure 5.

The work piece flfisho'wn in' Figure '7 is entirely cl'osediat its end 8|. The particular form of the end 8;? as illustrated in Figure 8 constitutes no 1 part er the present invention.

Thegeneral' org aniization of the dies whereby the initially'openend of thework piece 80, is at least partlyclosed is similar to that already described, but the work" piece is inverted, the base platel' l fl constituting a d-iehaving a cavity at I20, the wall of which performs theclqsing; operation.

The sliding blocks I-il correspond generally to the block-s l5 of the apparatus previously dis closed, but instead oi'holding theworl; stationary, these blocks constitute, in efiect, retractible portions of the die in which the work is formed, the work piece being, movable. downwardly between the blocks in the course of' the forming operat'IiQHL. Theplate zlin carried by guide pins 26 and spring 21 from the punch plate 23 is similarin its tin and anticipa e the d e 25 0f the apparatus previously disclqsed, but, its cavity 280 is merely fitted to the closed end of the work piece and consequently does not act as a die in this a p r When the work piece is held: between. the advanced: guide blocks r50, its cylindrical free marginal" portion 82 will be approximately at the top of the die plate l"lf0 as shown in Figure 9,. When the punch descends it will force the work piece downwardly between the guide blocks @150 into the recess I20, with the. result that the free margin 82' of the work piece will be forced the, position indicated in dotted lines at 82c Figure 3' and Figure 10;,

In the second swaging operation a further clos n o the of he wo k ce wi l be efiected in the die l'l'l, as indicated in Figure 11, leaving the free margin as shown at 8212 in Figures 8 and 11.

The final operation by which the margin of the work piece will be forced to the position 820 may be identical with that shown in Figure 3, and consequently is not illustrated.

It will, of course, be understood that before the first operation and the second operation the work will preferably be annealed. An alternative form of annealing apparatus which is preferred in practice is shown in Figure 12. Thelconveyor chain-t iii moves in a. guide channel 320 and pro.- pels along the upper surface of the channel blocks 34 I which are placed: at suitable intervals and support pins 3%, on which spindles 343' are rotatably mounted. Each such spindle has a friction rollerat its, conveniently made of rubber or the-like, and arranged to bear frictionally: on a stationary" friction bar 3455 disposed along the pathof travel of the conveyor.

Each of'the spindles 343 carries a cup at 346 inwhichthe workpiece Bli is disposed in the path oiflame jets issuing from the burner openings 39 in the fuel supply pipes 40.

It will; ofcourse, be understood that the various types: of dies are interchangeable, as are the an: nealing devices.

Bhe operation involved in the production of the finished work piece are not in any sense spinning operations, since the pressure is, in every instance, axiallydeveloped. Preferably, all or the pressing on forming operations are performed at atmospheric temperature, or, at least at such" temperature that the work piece can conveniently be handled. The concave surfaces of: the respective dies, upon which the pressing or-f'orming actually depends, act abruptly in each instanceand uniformly form all sides of the work piece simultaneously without spinning or-preliminary heating except for such residual heat as may be left in the work piece following one of the annealing-operations which intervenes between successive pressing operations; In refer-- ring to the press operations as being performed cold, I dolnot mean to imply that residual-heat isnecessarily or even preferably absent; I simply mean that since perfect results maybe achieved with the work entirelycold, heat is not only unnecessary but plays no important part in the process. It isusually not used because it makes handling more difficult.

The resulting product, even when made of steel, i-sexceptiona-llzv smoothlyiinished, with no flaws or wrinkles, and has surprising uniformity throughout. As applied-tog, hand grenade casing, this last fact is of'importancebecause it has been found that hand grenades employing casings .made in accordance with the present invention fragmentateinto pieces of surprisingly uniform size, this being a very desirable characteristic.

I claim:

1. Apparatus for closingthe open end of a tube and} comprising in combination a support for the tube having socket means in which the tube is laterally confined, a pressmember and a platen member for engagement with the ends of the tube, one of said members comprising. a die having a concave portion axially engaging the open u em as a m mbers a ac ach oth whereby-the open end is reduced cross section while the side of the tube is supported by said confining means, in further cqmh naticn with W k c n ing up ort n lo means omprising separabie parts mounted on said support and having cooperating recesses adapted to receive and. substantially completely envelop the work below said die, at least one of said blocks being movable transversely respecting the support for work admission and release, the die and at least the laterally movable block having means interlocking in the advance of the die to restrain the block against lateral movement from the work.

2. Apparatus for closing the open end of a tube and comprising in combination a support for the tube having socket means in which the tube is laterally confined, a press member and a platen member for engagement with the ends of the tube, one of said members comprising a die having a concave portion axially engaging the open tube end as said members approach each other, whereby the open end is reduced in cross section while the side of the tube is supported by said confining means, in further combination with work confining and supporting block means comprising separable parts mounted on said support and having cooperating recesses adapted to receive and substantially completely envelop the work below said die, at least one of said blocks being movable transversely respecting the support for work admission and release, the said blocks each being shouldered to provide male interlock surfaces, and the die having female interlock surfaces engageable with the said surfaces of both of said blocks in the advance of the die, whereby said die locks said blocks and secures the movable block against lateral movement when the die is advanced.

3. In a device of the character described adapted to act upon a generally cylindrical tube having an open margin for the reduction of such margin and at least a partial closing of the tube, the combination with a press member, of a pair of blocks having companion recesses, together adapted to constitute complete lateral enclosure for portions of said tube, at least one of said blocks being laterally movable respecting the press member for admission and discharge of tubes from confining engagement between said blocks, and

a second press member movable toward the first i press member and comprising a cylindrically walled recess portion adapted telescopically to receive wall portions of the tube adjacent said open margin, said recess portion of the die being adapted to cooperate with said blocks to substantially complete the external support of the tube wall, and means at the end of the aforesaid recess portion of the die comprising an inwardly and axially inclined cam surface for engagement substantially uniformly with all marginal portions of the tube in a direction to reduce such portions inwardly while providing external support therefor to force such portions to assume convex form.

4. In a device of the character described,

adapted to act upon a generally cylindrical tube having an open margin for the reduction of such 2 one of said blocks being laterally movable respecting the other for admission and discharge of tubes from confining engagement between said blocks,

.said second press member comprising a cylindrically walled recess portion adapted telescopically to receive wall portions of the tube adjacent said open margin, said recess portion being adapted to cooperate with said blocks to provide external 8 I support for the tube wall, and means at the end of the aforesaid recess portion of the second member comprising an inwardly inclined cam surface for engagement substantially uniformly with said open marginal portions of the tube in a direction to reduce such portions inwardly. while providing external support therefor to force such portions to assume convex form, together with a pilot bar projecting axially from said die intothe interior of said tube, and constituting means for limiting the reduction of, such margin.

5. In a device of the character described, adapted to act upon a generally cylindrical tube having an open upper margin for the reduction of such'margin and at least a partial closing of the tube, the combination with a tube supporting base, of a pair of blocks having companion recesses, together adapted to constitute complete lateral enclosure for portions of said tube, at least one of said blocks being laterally movable respecting the base for admission and discharge of tubes from. confining engagement between said blocks, and a die movable toward the base and comprising a cylindrically walled recess portion adapted telescopicallyto receive wall portions of the tube adjacent said open margin, said recess portion of the die being adapted to cooperate with said blocks to substantially complete the external support of the tube wall, and means at the upper end of the aforesaid recess portion of the die comprising an inwardly and upwardly inclined cam surface for engagement substantially uniformly with all marginal portions of the tube in a direction to reduce such portions inwardly while providing external support therefor to force such portions to assume convex form, together with a pilot bar projecting axially from said die into the margin of said tube and constituting means for limiting the reduction of such margin, the support having a boss and the pilot die and registering socket engageable therewith in themost advanced position of the die.

CHARLES J. STUART.-

. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 440,951 Knapp Nov. 18, 1890 529,597 Cayley Nov. 20, 1894 537,014 Burton Apr. 9, 1895 840,091 Schumacher et al. Jan. 1, 1907 1,266,750 Adams Y May, 21, 1918 1,498,450 Greve June 17, 1924 1,953,421 McCann Apr.. 3,-1934 2,030,818 Harter Feb. 11, 1936 2,038,165 Criley Apr. 21, 1936 2,069,858 Squires Feb. 9, 1937 2,085,189 Graf June 29, 1937 2,106,495 Debor vJan. 25, 1938 2,130,699 Reinartz Sept. 30, 1938 2,309,181 Franck Jan. 26, 1943 2,321,085 Hubbard Jun 8, 1943

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