US2181577A - Method for sizing the terminals of pipe fittings - Google Patents

Description

Nev. 28, 1939. H E. M. CARTWRIGHT 2.181.577 METHOD FQR SIZING THE TERMINALS 0F PIPE FITTINGS Filed June 22, 1938 v 4 Sheets-Sheet 1 Hefarfneya Nov. 28, 39- E. M. CARTWRIGHT I 2.181577 METHOD FOR SIZING THE TERMINALS OF PIPE FITTINGS Filed June 22, 1938 4 Sheets-Sheet 2 4 Sheets-Sheet 3 E. M. CARTWRIGHT 'Filed ane 22, 1 958 METHOb FOR SIZING THE TERMINALS 0F PIPE FITTINGS Nov. 28, 1939.

Nov. 28,1939, E. MLCARTWRIGHT 1 L5 METHOD FORSIZING THE TERMINALS 0F PYYIPEFITTINGIS v Filed Jun 22,1938 4 Sheets-Sheet ,4

Iv M l/5- Patented Nov. 28, 1939 PATENT OFFICE METHOD FOR SIZING THE TERMINALS OF PIPE FITTINGS Eugene M. Cartwright,

North Woodbury, Conn,

assignor to Chase Brass 8; Copper 00. Incorporated, Waterbury, Conn., a corporation Application June 22, 1938, Serial No. 215,177

4 Claims.

This invention relates to an improved method for shaping and sizing the terminals of elbows, Ts, and other tubular articles constructed of wrought metal and designed to be telescopically interfitted one with another preliminary to uniting them by means of a sweat-soldering operation.

The primary object of the present invention is to provide an improved method whereby the terminals of wrought-metal tubular articles of the character referred to may be sized and shaped with a high degree of accuracy; whereby the metal composing the terminals may be wrought or worked in such a way as to enhance their hardness and tenacity; and whereby the said terminals may be rendered capable of forming sweat-soldered joints of high quality with interfitted pipes, pipe fittings, and the like.

One object of the invention is to provide an improved method whereby certain undesirable conditions and inherent imperfections in the un-I sized pipe-fitting terminals may be overcome in a simple and effective manner in the finished pipe fitting.

Another object of the invention is to provide an improved method whereby an improved sequence of cold-working operations may be employed on unsized pipe fittings to produce shaped and sized pipe fittings of greatly-improved quality for their intended purposes.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art and which are not claimed in any separate application.

In the accompanying drawings, in which cer tain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a diagrammatic front elevation of suitable apparatus for oversizing the terminal of an unsized pipe fitting T by an expanding operation performed on the T; I

Fig. 2 is a side elevation of Fig. 1 with one of the separable holder-blocks for holding the T being removed and an unfinished T being shown in position to have one of its terminals expanded to oversize;

Fig. 3 is a view similar to Fig. 2 showing a mandrel of oversized predetermined diameter at the end of its operating stroke;

Fig. 4 is a medial vertical section of the drawdie assembly whereby the oversized terminal pipe fitting T may be sized by a reducing cold-working operation, a sizing mandrel of predetermined diameter'being shown atthe commencement of its stroke;

Figure 5 is a view similar to Fig. 4 showing the sizing-mandrel with the attached pipe fitting T at the end of the downward movement of said 5 mandrel;

V Fig. 6 is a transverse section on the line 66' of Fig. I

Fig. '7 is a topplan view of the two-part drawdie assembly;

Fig. 8 is a side elevation of a T-blank partly in section with its oversized terminals indicated by broken lines;

Fig. 9 is a similar view of the finished T; I

Fig. 10 is a side elevation of the draw-die assembly for use in connection with a pipe-fitting elbow;

Fig.11 is a medial longitudinal section of the draw-die assembly shown in Fig. 10;

Fig. 12 is a fragmentary section on the line l2-l2 of Fig. 11;

Fig. 13 is a side elevation of an elbow with oversized terminals partly in section on one of said terminals and indicated in dottedlines on the other one of said terminals; and

Fig. 14 is a side elevationsimilar to that shown in Fig. 13 with a fragment of the wall of one terminal broken away to show the modified wallthickness subsequent to the sizing operation performed thereon.

According to heretofore well-known methods of shaping and sizing the terminal members of pipe fittings, pipes, etc., of the type designed to be telescopically interfitted and united together by means of sweat-soldering operations, the pipe fitting is arranged in a two-part holding-block having complementary cavities formed in the respective members of said holding-block to receive the terminal portion of a pipe-fitting blank and wherein said terminal portion of the pipe-fitting blank is sized and interiorly-shaped by a single cold-working expansion of the unsized terminal of a pipe fitting by a mandrel of predetermined diameter greater than that of the interior surface of the unsized terminal. This method of procedure has produced results that are not entirely satisfactory due largely to certain inherent imperfections and undesirable conditions in the unsized pipe fitting constructed in the usual manner, causing variations in wall-thickness and texture of the metal in the sized pipe fittings.

Efiorts have been made to overcome these drawbacks by resorting to reaming operations performed on the terminal-portion of the unsized pipe fitting-with a view to rendering the wall- 55 thicknesses as uniform as possible before the said terminalportions were subjected to the expanding or sizing operations by forcibly inserting thereinto a mandrel of predetermined size or diameter corresponding to that of the interior surface of the sized terminals. The intended purpose of this procedure was to equalize the strains within the metal in such a way as to prevent the sized terminal from going out of round after the expanding operation performed on the unsized pipe-fitting terminal. Due to the lack of uniformity in the effects produced by these reaming and similar operations upon the unsized pipe-fitting terminals, the walls of which were of non-uniform thickness, eflorts in this direction were not entirely successful since a sizing operation performed on an unsized pipe-fitting terminal of the usual form, tends to produce unequalized strains in the metal walls of the sized terminals with a consequential tendency for the sized terminals to spring "out of round after the sizing operations.

According to my co-pending application Serial No. 146,449 which was filed in the U. S. Patent Ofilce on June 4, 1937, now patent No- 2,174,967 the terminal-portion of an unsized pipe fitting is subjected to two successive cold-working op-.

erations, one of which consists in forcibly inserting into an unsized terminal of a pipe fitting a mandrel of predetermined diameter larger-than that of the interior surface of said terminal and the second of which consists in ironing-out the exterior surface of said terminal on the said mandrel by a constricting draw-die of predetermined diameter less than that of the exterior surface of said terminal after it is expanded. For this purpose, the body-portion of an unsized pipe fitting is clamped in a holder comprising separable clamping-blocks, the sizing-mandrel being forcibly. inserted into the unsized terminal in a direction towards the body-portion of the pipe fitting. This sizing operation is followed by a longitudinal movement of the draw-die member over the normally-stationary exterior wall of the expanded terminal to produce a cold-flowage of the metal away from the body-portion of the pipe fitting on the sizing-mandrel.

According to the present invention, analogous eflects on the tubular wall of an unsized pipe fitting, are produced in a simpler and more efiective manner in two successive stages, during the former of which a mandrel of predetermined diameter larger than that of the interior surface of an unsized terminal, as well as slightly oversized with respect to the sized interior of the finished terminal is forcibly inserted into the unsized terminal of the pipe fitting preparatory to the next operating stage. For this primary stage, a pipe-fitting holder of somewhat similar character to that shown and described in my aboveidentified co-pending application may be employed. After the completion of this primary cold-working operation, the pipe fitting with its oversized terminal is removed from the pipe-fitting holder and positioned in a pipe-fitting holder or draw-die support of peculiar construction to be hereinafter described. Mounted in the pipefitting holder or draw-die support, is a normallystationary ring-shaped draw-die which is suitably constructed to receive the oversized pipefltting terminal positioned above and supported by an annular draw-die ledge of the draw-die which, during the secondary stage of the colddrawing operation, exercises a double function in coopution with a mandrel of predetermined diameter less than that of the interior diameter of the oversized terminal and which is inserted into the oversized terminal in accurate coaxial relationship to the annular draw-die. Subsequently, this mandrel is forced downwardly through the said draw-die to drive the said terminal through and past the draw-die to efiect an ironing operation on the exterior surface of the terminal on the sized mandrel. The effects of this operation are manifold in that it sizes the oversized terminal; reduces the thickness of the terminal wall; reduces the outside diameter of the terminal and renders it more truly cylindrical; improves the texture and tenacity of the metal; and tends to equalize the strains produced in the unsizedpipe fitting during its formation. As a direct result, the inner or sized surface of the terminal may be interfitted to within a refined degree of tolerance with pipes, other pipe fittings, and the like, to be connected thereto by means of sweat-soldering or the like.

The particular apparatus illustrated in Figs. 1 to 3 inclusive isdesigned primarily for expanding the terminals of wrought-metal pipe fittings .into bellmouthed form for the telescopic reception of pipes, tubes, or terminals of other pipe fittings. The said apparatus includes a carrierblock or member 20 connected to the gate or ram of a power-press (not shown), a sizingmandrel 2| being shown depending from the under-side of the saidcarrier-block or member 20 and provided with a terminal or pilot-nose portion 22. The said mandrel is of predetermined diameter larger than thatof the inner surface of the unsized pipe-fitting terminal into which it is to be forcibly inserted.

Arranged below the sizing-mandrel 2| is a pipeholder which is generally designated by the reference character 23, said fitting-holder being suitably constructed to rest upon the upper surface of the bed of the power-press (not shown). In the form shown in Figs. 1, 2 and 3, the fittingholder comprises two opposed separable holderblocks 24-24, each of which is suitably recessed to jointly accommodate a wrought-metal T, such as that designated generally by the reference character 25. The complemental members or holder-blocks 24-24 of the fitting-holder", may be firmly held together by any suitable'means, such, for example, as plungers 26-26 in Fig. 1.

The pipe fitting 25, shown in the form of a T in Figs. 1 to 3, is provided with an unsized branchterminal 21 which, for the primary stage of the sizing operation, is arranged in a cylindrical portion 28 of the ,T-shaped recess formed between the opposed holder-blocks 24-24,. said branchterminal being arranged on a vertical axis. and in coaxial alignment with the sizing-mandrel 2|. During the downward movement of the carrier-block or member 20, the pilot-nose 22 of the sizing-mandrel 2| enters the upper end of the branch-terminal 21 (one of three similar terminals of the T) and guides the said mandrel 2| thereinto to. produce an expansion of the branch-terminal 21 within a cylindrical recess 28 formed in, the holder-blocks 2l2l, jointly.

aieus'i'r cooperates with the sloping expanding shoulder 29 to forman outward bulge infthe terminal; 31 v I conditions, as the terminal in: is driven down,- wardly by the'mandrel 3Q through and past the 1 annular draw-die ledge 31. the exteriorsurfaoe which constitutes the .lowerborder of the oversized bellmouthedform 21a of the'terminal;

shown lun '1 After the remaining two line=terminals er the T 25 have been expanded to' an oversize in the foregoing manner, thesaid terminals are positioned one at a time in a pipe-fitting housing or draw-die support of peculiar form. shown in Figs. 4 to 7 inclusive-and designated generally; by the reference character 3|. The said housing or support 3| comprisescomplementary parts or per tions 3233 opposed each to the other and held together by any suitable means such, for example,

as the plungers 33--33 shown in Fig; 6} Mounted in the top wall of the housing or support 3| is a ring-shaped draw-die 34 comprising semicircular sections 34a--3 4a, said sections'being secured in;

position by means of suitable screws 35. The said draw-die 34 is provided with aninner peripheral wall 36 of suflicient "sizeto permit the coaxial alignmentof each oversized bellmouthed termi nalfla of the T "placed therein, withrespect to an annular draw-die ledge 31 'of'theringshaped draw-die 34, by means-of a terminalsizing-and-moving mandrel to be presently described. The annular draw-die'ledge 31 is of predetermined diameter less than that 'of the outer surface of ltheoversized-terminal 31a of the pipe fitting "when the same is expanded, and is suitably constructed to supportably engage the inner edge of the said over-sizedbellmouthed terminal. The housing or support 3| is suitably constructed to be placed uponthe bed plate (not shown) of a power press and when properly located on the said bed-plate in position to support the annular draw-die ledge 31 in accurate coaxial alignment with the' longitudinal'axisof a" reciprocatory terminal-sizing and pipe-fitting-actuating mandrel. operated by the power-press'in the manner to bepresently describedf The said power-press may include a carrier-blocker mem ber 33 to which is secured the upper end of a sizing-mandrel 39 of predetermined diameter slightly less than that 'of the interior diameter of the oversized bellmouthed terminal 31a; The

said sizing-mandrel is .providedat its lower end" with a pilot-portion and a shoulder-portion 4| which operate to. centralize the terminal with I respect to the mandrel 39 as the'said pilot 40 moves downwardly through said terminal.

The sizing-mandrel, is preferably constructed of tool-steel, carefully ground to size around its exterior surface to adapt itto perform an accurate sizing operation upon-the interior surface 0f--the bellmouthed terminal 21a or othersimilar 'ter-.- I

minal when thesame is forcibly driven downwardly through and past the annular draw-die ledge 31 so that when the sized terminal isintere fitted with anotherpipe fitting, pipe, or the like,

an interfitting connection with arefined degree of tolerance maybe formed between the .joint-.- forming walls to insure the necessary capillarity between the surfaces to be Joinedv by means of sweat-soldering.

It will be understood from the foregoing hiei scrlption that as'the sizing-mandrel 39 is forcibly moved downwardly into the bellmouthed terminal interior surface substantially in coaxial align the annular draw-die ledge 31; Under merit the common axis ofthe mandrel 33 and p of the expanded terminal will be ironed out or v to provide the terminal with an outer surface which is more truly cylindrical. 'As shown in Fig.5, the Joint movement 'of the sizingman'drel and terminal through'the annular draw-die ledge.

31 operatestofastenthe said terminal to the sizing-mandrel 33 witlia close frictional grip by means of which the pipe fittingis suspended r the terminal has become'disengagedfrom je annular draw-die ledge 3'l. f As the mandrel 33 1 moves upwardly in preparationforj another operl ation, the pipe-fitting T 23 is stripped or detached therefmm by the s me 'tjoz thefiatter w th'i the under-surface of the draw-die ledge 31. I

It jwill be: understood fromi the' foregoing :de scription that the pipe-fitting T' is completed by a repetition of the shaping and sizing operation described above, on both of the terminals ofthe main bodyor run-portion thereof. As shown diagrammatically in, Fig. 8, the above-described operation peri'ormed'on each of the plain terminals 21 of an unslzed' pipefitting 34' produces first an oversizedbellmouthed terminal flashown in "dotted lines in Fig; 8, and then a reduced shaping and-sizing of the said oversized bell mouthed terminal 310 to produce a pipe-stung T having a reduced bellmouthed terminal' 311;

as shown in Fig. 9;

Figs. '10 to 14 inclusive show suitableapparatusf for producing elbow in'accordance with the presient'i'nvention, said elbows belng'provided with bellmouthed terminals having the improved qua]!- [itie's inherent in the bellmouthed terminals formed in the above-describedmanner. .Forthis I purpose, a pipe-fitting housing and draw-die sup-V port'designated generally by the reference character 43 is prbvided, wherein a continuingdownward movement of an elbow," designated general-v 1y by the reference character 43,,is accommo- I minal of the elbow.

In the form shown, the pipe-fitting. housing. H and draw-die support 43 comprises oppositely arranged complementary sections or members "-44 which may be held together in any suitfdated during a shaping and sizing operation con-v ducted on a preexpanded slightly-oversized terthe housing 0,15 a two-part ring-shaped draw die 45 preferably constructed in separable sec.-

"tions to correspond; with the parting-plane of.

the sections 44-44 of the housing 43. The twopart ring-shaped drawdie 43 is, provided 8t its bottom-end withan annular draw-die ledgedes ignated' by the reference character 43 and prei'-.

erably constructed in two semicircular sections: separable in the parting-plane ofthe sections 4444 of the housing 43' to permit the positioning therein, by a'lateralm'ovement, of a preexpanded slightly-oversized terminal 41 or anelbow. It will,

be understood, in this connection, that the elbow.

40 shown in rugs. 10 'to 13 inclusive, is provided at its respective opposite ends. respectively, with slightly-oversized terminals 41 and which have been preexpanded and preformed substantially in v pipe-fitting T 25, as shown in Figs. 1 to 3. It will be understood, furthermore, that the annular draw-die ledge 46 is of predetermined diameter .less than, that of the exterior surface of the bellmouthed terminals 41 and with which the elbow 48 has been preformed. The split ringshaped draw-die 45 maybe retainedjin position i in the top-wall of the housing 43 by means of screws 48. g

The oversized terminal 56 of the elbow 48 is first mounted upon a cylindrical head 5| of pre- 1 determined diameter fitting the interior surface of the said terminal 50,after which the complemental terminal 41 is brought into position within the upper portion of the draw-die 45, the respective halves of which are brought together concurrently with the clamping together of the sections 44-44 of the housing 43.

l The cylindrical head 5| is provided with a threaded stem 52 mounted in a sleeve 53, which K 46 and a sizing-mandrel63 to be hereinafter described, during a continued downward movement of the said mandrel and terminal through and past the said annular draw-die ledge 46, the

present invention contemplates suitable means for maintaining the longitudinal axis of the threaded stem 52 and'the cylindrical head 5| perpendicular to the vertical axis common to the annular draw-die ledge 46 and the sizing-mandrel 63. For this purpose and in the form shown in the drawings, a plate 55 is threaded onto the stem 52 and is provided with a finished surface in slidable engagement with finished guide-surfaces 5656 extending parallel with and on each of the respective opposite sides of the vertical slot 54. The disk-like plate 55 isprovided with a retaining-rib 51 which slides in a vertical groove 58 formed in the inner face 56 in the adjacent end-wall of the housing 43 (Fig. 12) whereby the unit compressing the stem 52 and the parts thereon, is movably organized with one of the sections I 44 of the housing 43, to thus maintain the said unit in place when the sections 44-44 are separated during the removal or insertion of a fitting'therebetween.

For the purpose of retaining the disk-like plate 55 in slidable abutment with the surfaces 56-56 during the vertical movement of the former, a

second disk-like plate 59 is threaded onto the outer portion of the threaded stem 52 to slidably contact with finished guide-surfaces 560-5611 extending along the outer margin of the vertical groove 54. Threaded to the outer end of stem 52 is a lock-nut 60 which is adapted to secure the plates 55 and 59 in abutment with opposite ends of the sleeve 53 after the cylindrical head 5| has been axially adjusted in proper supporting position with respect to the terminal 50 of the elbow 48. For the purpose of axially adjusting the cylindrical head 5| within the terminal 56, an outer reduced end-portion 6| of threaded stem 52 is provided with a'kerf 62 to receive a screw driver. v

It will now be understood from the foregoing description that after an elbow 48 has been correctly positioned within the housing 43, a dOWll-r tion of the bellmouthed terminal 210 of the ward displacement of the slightly-oversized terminal 41 of the elbow through and past the annular draw-die ledge 46, willbe constrained to a path coincident with the axis of the said annular draw-die ledge. The housing 43 is constructed to be placedtupon the bed-plate (not shown) of a power-press which includes means of suitable construction for moving the sizing-mandrel 63 in a path perpendicular to the bed of the said power-press.

With the elbow 48 properly positioned in the housing 48 in the manner described above, the said housing 43 is arranged in a predetermined position on the bed-plate of the. power-press with the sizing-mandrel; 63 in coaxial alignment with the vertical axis of the annular draw-die ledge 46. A pilot 64 at the bottom end of-the sizing-mandrel 63 is formed of suitable size and shape to enter theunexpanded portion of the elbow immediately below the oversized terminal-portion "thereof. When thesaid pilot 64 is lowered into engagement with the inner wall of the ,unexpanded portion of the elbow 48, a sloping thrust-shoulder 65 located between the pilot 64 and the main body' of the sizing-mandrel 63, is brought into engagement with the inner wall of the terminal 41 at its lower end. With the several parts thus arranged, the downward movement of the sizingmandrel 63 is continued and imparts downward movement to the terminal 41 through and past the annular draw-die ledge 46, the said downward movement being terminated after the upper edge of the terminal 41 of the elbow 48 has been moved below the annular draw-die ledge 46 to-a position indicated in dotted lines in Fig. 11.

As the elbow 48 is forced bodily downward as just above described, the guide-unit comprising the head 5| and the parts organized therewith, serves to maintain the axes of the two terminals 41 and 50 at a predetermined angular relationship,-i. e.,, 90 in the instance shown. The guideunit just referred to also constrains the bodily movement of the elbow'to a path parallel with the axis of the mandrel 63.

It will now be readily understood from the foregoing description that due to the arrangement of the annular draw-die ledge 46 in a normany-stationary position, inwhich it is rigidly held in. coaxialrelationship with respect to the reciprocating sizing-mandrel 63, the slightlyoversized terminal 41 of elbow 48 will be forcibly exterior surface of the terminal 41 will be ironed out into true cylindrical form and its tubular wall will be reduced in thickness. i

As shown diagrammatically in Fig. 13, the above-described shaping and sizing operation in a general way converts the relatively-large oversized and somewhat-irregular terminal 41 to a relatively-smaller sized terminal 41a having exterior and interior surfaces that are rendered cylindrical to a more refined degree. During this conversion in form, the hardness, tenacity and texture of the metal is greatly improved by a.

condensation and cold-fiowage of the metal longitudinally of the terminal during the radial contraction of the terminal to its final sine and shape.

The invention may be carried out in other specific ways than those herein set forth, without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. A method of sizing pipe-fitting terminals, comprising: forcibly inserting into an unsized terminal of a pipe fitting, a mandrel of predetermined diameter larger than that of the interior surface of the said terminal; in removing the said mandrel from the terminal thus expanded; in inserting into the said terminal thus expanded another mandrel of predetermined diameter slightly less than the diameter of the firstmentioned mandrel; and in ironing out the exterior surface of said terminal on the secondmentioned mandrel by a constricting draw-die of predetermined diameter less than that of the exterior surface of the terminal after it is expanded.

2. A method of sizing pipe-fitting terminals, comprising: forcibly inserting into an unsized terminal of a pipe fitting, a mandrel of predetermined diameter larger than that of the interior surface of said terminal; removing the said mandrel from the terminal thus expanded; inserting into the said terminal thus expanded another mandrel of predetermined diameter slightly less than the diameter of the first-mentioned mandrel; and in ironing out the exterior surface of said terminal on the second-mentioned mandrel 'by a constricting draw-die of predetermined diameter less than that of the exterior surface of said terminal after it is expanded, the said drawdie having a working surface substantially similar in shape to that of the second-mentioned mandrel; the. second-mentioned mandrel and draw-die being held in coaxial relationship during the ironing operation.

3. A method of sizing pipe-fitting terminals,

comprising: forcibly inserting into an unsised terminal of a pipe fitting, a mandrel of predetermined diameter larger than that of the interior surface of the said terminal and slightly larger than that of the interior surface of the sized terminal to be formed from the expanded terminal; in removing the terminal thus expanded from the said mandrel; in inserting into the said expanded terminal another mandrel of predetermined diameter substantially equal to that of the sized interior surface of the sized terminal; and ironing out the exterior surface of the expanded terminal .on the second-mentioned mandrel by a constructing draw-die of predetermined diameter less than that of the exterior surface of the terminal after its expansion on the first-mentioned mandrel whereby the said interior surface of the expanded terminal is reduced to sue.

4. A method of producing a sized bellmouthed pipe-fitting terminal, including: introducing into an unsized terminal-portion of a pipe nttins. an oversized mandrel of predetermined diam slightly larger than that of the inner surface of the finished bellmouthed terminal to be formed on the pipe fitting; removing the oversized bellmouthed terminal from the said mandrel; placing a neck-portion of the pipe fitting at the inner end of the oversized bellmouthed terminal in one portion of a split-ring-shaped draw-die of predetermined diameter slightly less than that of the exterior surface of the oversized terminal: placing a complementary portion of the said draw-die in assembledposition with respect to the first said portion; inserting into the said terminal a sizing-mandrel of predetermined diameter slightlyless than that of the inner surface of the oversized terminal and substantially the same as that of the inner surface of the finished bellmouthed terminal; and in forcibly moving the last-mentioned mandrel with the said terminal through and past the said ring-shaped draw-die to effect a cold-working of the oversized terminal on the last-mentioned mandrel and a sizing of the inner surface of the said .ter-

minal.

EUGENE M. CAR'I'WRIGH'I'.

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