US2975510A - Method of forming branched fittings - Google Patents

Description

March 21, 1961 H. c. HEUSS ETAL 2,975,510

METHOD OF FORMING BRANCHED FITTINGS Filed Aug. 27, 1957 s Sheets-Sheet 1 March 21, 1961 c; EUss ET AL 2,975,510

METHOD OF FORMING BRANCHED FITTINGS Filed Aug. 27, 1957 5 Sheets-Sheet 2 March 21, 1961 c, HEUss ETAL METHOD OF FORMING BRANCHED FITTINGS Filed Aug. 27, 1957 5 Sheets-Sheet 5 JiZZ/EMjOKS 3 7 0 72 C Jwss,

ljaqpi Zara/a.

3,975,510 METHOD OF FoRMrNG BRANCHED FITTINGS Henry C. Heuss, Evergreen Park, and Joseph Zima, Chicago, 111., assignors to Crane C0., Chicago, 111., a corporation of Illinois Filed Aug. 27, 1957, Ser. No. 680,534

7 Claims. (Cl. 29-157) The present invention relates generally to a method of forming branched pipe fittings and the like, and more particularly to an improved method of forming Ts and other branched fittings from tubular blanks.

One known method of forming Ts and other branched fittings from tubular blanks involves inserting in the blank a fusible alloy or other flowable, incompressible material, and compressing the blank longitudinally between oppositely acting plunger-s or the like of a suitable press while the blank is held in separable die means formed with a radial opening or recess into which a portion of the material of the blank is forced so as to define a branch, the die means otherwise preventing radial or lateral expansion of the blank. The material of the blank is extruded into the die recess by the action of the fusible alloy or other fusible material under pressure. The necessary material for the branch is supplied by initially forming the blank of somewhat greater length than the predetermined length of the rough fitting to be formed, the excess being utilized for the branch by flow of the blank material under the applied pressure. This known method is generally disclosed in the expired Seeber et al. Patent No. 2,111,695, issued March 22, 1938, and the Arbogast Patent No. 2,557,403, issued June 19, 1951, to which reference may be had for a more detailed explanation.

While this prior method is generally satisfactory, it has the drawback in practical application that in order to form large sizes of fittings from blanks of large diameter, a press of considerable power is required in order that the great pressure necessary for large fittings be applied. Although such a press can of course be used for forming smaller size fittings also, it represents a large capital investment considerably in excess of that required for a press of lower capacity satisfactory for operation on the smaller fittings. This of course represents an added cost factor, especially in the usual case of the large fittings constituting a minor portion of total production.

In addition, branched fittings other than crosses, such as Ts or the like, formed by the prior method often have.

a thickening or build-up of the wall opposite the branch so great as to necessitate a boring or other operation to remove or reduce the build-up sufficiently to meet inspection requirements. This of course increases the cost.

The method of the present invention permits the use of a press of lower capacity than would otherwise be required for larger size fittings, and results in sufficiently less build-up practically to eliminate any operation for removing excess wall thickness. In addition, it greatly reduces the number of breakouts, or rough fittings bursting under the forming pressure. The method achieves these advantageous results by a procedure which, briefly stated, compresses a tubular blank longitudinally to shorten it to the predetermined length of the rough fitting while only partially forming the branch or branches, and then completes the branch or branches by.

States Patent ice pressure on the filler material alone without further longitudinal pressure on the blank, to extrude the branch or branches to the full desired height, or length, thereof. Various specific procedures may be employed, several of which are particularly illustrated and described. In each case, the volume of the filler material inserted in the blank plus that of any pressing means projected into the blank to act on the filler is less, during the longitudinal pressing and shortening of the blank, than the interior volume of the rough fitting to be formed, and is increased to the desired fitting volume, after the shortening of the blank is accomplished, to bring about completion of the branch extrusion.

It is an object of the present invention to provide a method of forming seamless branched fittings by pressing of tubular blanks which permits use of less pressure than would otherwise be required.

Another object of the invention is the provision of a method of forming branched fittings by pressing tubular blanks which results in a reduction of the usual increase or build-up of wall thickness opposite a branch.

Another object is the provision of a method of forming branched fittings from tubular blanks which reduces the number of fittings broken during the forming operation.

Other and further objects, advantages, and features of the invention will be apparent to those skilled in the art from the following detailed description thereof and the accompanying drawings, in which:

Figs. 1 to 4 inclusive are longitudinal sectional views through a tubular blank in die means, illustrating differ ent stages in the forming of a rough branched fitting, specifically a T, according to the method of this invention;

Fig. 5 is a view similar to Figs. 1 to 4, but illustrating a modification of the method;

Figs. 6 and 7 are similar to the preceding views, but

illustrate another modification of the method;

Figs. 8 to 10 illustrate still another modification of the method;

Fig. 11 is an enlarged fragmentary section through a rough fitting formed according to the invention, illustrating the difference in build-up typically produced by the method of the invention and by the prior method; and

Fig. 12 is another enlarged fragmentary section through a rough fitting produced by the method of this invention, illustrating the difference between the partially formed and complete branch.

Referring'first to Figs. 1 to 4 of the drawings, there is shown a tubular blank 20 of predetermined length, for example a section of seamless steel pipe, into which has been introduced a quantity of filler material 21. This material is substantially incompressible but flowable or plastic under pressure, such as Woods metal or like fusible alloy, or other material having the indicated properties. The blank 20 with the filler material therein is disposed in a die generally designated 22 formed of cooperable separable parts 23 defining when closed a uniform through passage 24, in which the blank fits snugly, and a radial or lateral recess 25 opening from the passage to define the branch of the rough fitting to be formed. A bore or like passage 26 preferably is provided extending axially from the recess to the exterior of the die part. Since the method is illustrated as applied to the formation of a T, a single recess 25 is pro- V vided, but it will be clear that more recesses may be 1 not shown, with the passage 24 in alignment with the rams. The ends of the rams may be provided with tapering recesses 28 for relief flow of the material 21. Each ram has a reduced end portion 29 formed to fit closely within the blank, and a shoulder 30 defined between the reduced portion and the main portion of the ram, which is formedto fit in the die passage 24. As evident from the drawings, the shoulders 39 engage the opposite end edges of the blank when the rams are actuated for a pressing operation, and the reduced portions 29 engage the filler material 21 within the blank.

The structure as so far described is generally similar to the disclosure of the aforementioned Patents 2,111,- 695 and 2,557,403, and to a certain extent the forma tion of the branched fittings employs the method generally disclosed therein. As will appear hereinafter, however, the present invention provides a method hav ing important and advantageous differences from prior methods.

The quantity of filler material 21 initially employed in the blank 20' is of a predetermined volume such that the combined volume of the filler material and the reduced end portions 29 projectable into the blank is less than the interior volume of the complete rough fitting to be formed from the blank. After the material has been inserted in the blank, and the blank disposed in the die 22 as shown in Fig. 1, the press is operated to advance the rams 27 toward each other and into the die passage 24 so that the shoulders 30- engage the ends of the blank 20, and the reduced portions 29 come into engagement with the filler material. Since the blank is confined and restrained against any radial or laterial expansion except into the recess 25,, a portion of the blank is extruded into the recess by the action of the filler material under the pressure of the rams, and the longitudinal pressure on the blank which causes a shortening thereof to provide the blank material from which the branch is formed. The pressure applied by the rams is continued until the blank has been shortened to a predetermined length corresponding to the desired length of the rough fitting, and movement of the rams is then stopped, preferably by automatic means incorporated in the press, such as limit switches or the like. This position of the rams is illustrated in Fig. 2. Since the combined volume of the filler material and the reduced portions 29 of the rams projecting within the blank is less than the full volume of the fitting, the portion of the blank extruded into the recess 25 forms only a partial branch 32, as clearly appears from Figs. 2 and 3. The circumferential portion of the partially formed branch 32 engages'the side wall of the recess 25 and the end portion of the branch engages the end wall of the recess, but the portion of the branch between the circumferential portion and the end portion does not extend as fully as might be-into the recess, or in other words the recess is not as completely filled by the branch as it might be. As will be apperent, the initial length of the blank 20 is sufficiently in excess of the rough fitting length as to provide suificient material for the complete branchon the rough fitting.

After the blank has been formed with the incomplete branch 32 and the blank brought to the desired rough fitting length as shown in Fig. 2, the rams 27 are retracted, and if necessary the die parts 23 are separated, to allow the insertion of additional filler material in the partially formed blank. As shown in Fig. 3, this is accomplished by a disk or ring of the filler material, of predetermined volume, inserted at each end of the blank, in this case a ring 33 applied over each of the tapered portions 21a formed by relief flow of the material into the recesses 28 and projecting from the main body of the material. While the additional or augmenting material is shown as supplied by means of two rings 33, it will be evident that more or fewer rings may be employed, or that the material may take other than a ring-like form if desired. The important point is that the volume of the added filler material is equal to the difierence in volume between the volume of the rough fitting to be formed and the combined volume of the initial quantity of filler material 21 and the reduced end portions 29 of the rams, so that the volume of the end portions plus the initially employed filler material and the added material substantially equals the interior volume of the rough fitting. For simplicity in expressing herein the volume of filler material, the recesses 28, or more precisely the portions thereof extending inwardly beyond the reduced end portions 29, are disregarded, though in practice a sufiicient quantity of filler material must of course be used to allow for the amount thereof flowing into such deeper portions of the recesses. Since the portions of the recesses in the reduced portions 29 obviously decrease the volume thereof while correspondingly increasing the volume of filler material, the combined volume remains the same when the recsses do not extend inwardly of the end portions 29, as well as when the recesses are not provided; but as the recesses may or may not be provided, and when employed may or may not extend beyond the portions 29 into the main portions of the rams, and as the recesses are not necessarily completely filled by the relieving fiow of the material, a long and complicated statement would be required to express the volume of filler material if all the various possibilities were to be set forth. Actually, any quantity of the material provided for flow into such deeper portions of the recesses may be considered, from the standpoint of this invention, merely as replacement or compensation for the material of the main portions of the rams removed in providing the deeper recess portions, and not as an effective part of the filler material acting to cause branch extrusion; and the simplified expression of the volume of filler material is thus accurate and definite.

After the initially inserted filler material 21 has been augmented by the rings 33 or other form of additional filler material, the rams 27 are again operated. As the rams move toward each other, the reduced portions 29 engage the added material and by reason of the increased volume cause the filler material to force the partially formed branch 32 into a completely formed branch 34 of the rough fitting, as will be clear from Fig. 4. The shoulders 30 of the rams come into engagement with the ends of the blank, but apply no pressure thereto, since the ram movement is stopped at this point as in the case of the initial pressing operation illustrated in Fig. 2. The added material is blended and merged with the original quantity of filler material, and the circumferential portion of the partially formed branch 32 is extended for substantially the full axial extent of the recess 25 to form the complete branch 34. To allow comparison with Fig. 2 for greater clearness, a dotted line indication of the volume of the rings 33 is given in Fig. 4 at 33a. The radius of the portion of the branch extending between the end portion and circumferential portion thereof becomes much smaller in the complete branch 34 than in the partially formed branch 32, as will be evident from a comparison of Figs. 3 and 4, and as made even more clear in Fig. 12. The rough fitting with the completely formed branch 34 may then be removed from the die. the filler material removed and recovered, and the branch 34 opened in any desired manner, as by severance in the plane indicated by the line S in Fig. 12. The fitting then may be finished in any manner desired. 4

One modification of the method as described is sub stantially the same as already explained, up to the point at which rings 33 of additional filler material are applied. According to the modification, rings 35 prefer ably of substantially the same material as the rams 27 are disposed over the tapered relief portions 210 projecting from the body of filler material 21, as shown in Fig. 5. The rings correspond in shape and dimensions to the reduced end portions 29 of the rams, and the appertures 36 therethrough are preferably formed as tapered extensions of the recesses 28. Of course, other means for the same purpose may be used instead of the rings 35, especially when the recesses are not provided. The dimensions of the rings 35 or other similar means are such as to provide the desired increase in combined volume of the reduced portions 29 and filler material 21, it being evident that the rings 35 or other means are in effect auxiliary means or additions to the reduced ram portions 29. After applictaion of the auxiliary means, the rams are operated to apply pressure to the filler material 21 through the end portions 29 and rings 35 and thus form a complete branch 34 of the rough fitting in the recess 25. The rams are thereupon retracted and the die 22 opened, the rough fitting being removed and the rings 35 taken out of the fitting for re-use. The filler material 21 may be recovered for reuse later if suitable, the end of the branch 34 cut off, and the rough fitting finished to the desired final condition.

Another modification of the invention is illustrated by Figs. 6 and 7. In this modification of the method, the filler material 21 is inserted in the blank 20 as in the firstdescribed method, but in a quantity corresponding to the volume of the rough fitting to be formed, the amount of material for which relief is provided by the recesses 28 to form the tapered projections of material 21a being disregarded as explained in the case of the prior modifications described. The rams 27 with the reduced portions 29 and shoulders 30, together with the recesses 28, substantially as already described, are employed together with the die 22. A pair of annular members 40 formed of substantially the same material as the rams 27 are also provided, having an outer configuration corresponding to that of the main or enlarged portion of the ram, and an internal aperture conforming to the reduced portion 29. The annular members are disposed on the reduced portions in engagement with the shoulders 30, and the rams are moved toward each other through the die passage 24 after the blank 20 with the filler material therein has been disposed in the die 22 in the manner shown in Fig. l. The annular members 40 engage the ends of the blank, and the reduced portions 29 engage the filler material, but the projection of these reduced portions within the blank is limited and reduced by the thickness of the annular members 40. As the blank is shortened to the desired length if the rough fitting and the incomplete branch 32 is extruded into the recess 25 substantially as already described, the pressing movement of the rams is halted by any suitable means, preferably automatic. The effect of the annular members 40, by spacing the shoulders from the blank ends, is to reduce the effective volume of the reduced portions within the blank, plus that of the filler material, to less than the interior volume of the rough fitting. This will be evident from Fig. 6, in which the blank is shown, as shortened to the predetermined length, with the rams halted. The rams are then retracted and the annular members 40 removed from the reduced portions 29 of the rams, and the rams then again actuated in a pressing operation. The reduced portions 29 in this second pressing operation project completely into the blank 20 and thus the effective volume thereof is increased to provide a combined volume of filler material 21 and the reduced portions 29 suificient to force the material if the partially formed branch 32 into the desired shape of the complete branch 34, substantially as described hereinabove. The rough fitting may then be removed from the press and finished as desired. In this modification of the method, it is necessary that suitable limit switches or other means he provided which will efi'ect halting of the pressing movement of the rams in the first pressing operation at the positions indicated in Fig. 6, but allow movement of the rams inwardly 'until the shoulders. 30 engage the ends of the shortened blank, as shown in Fig. 7, in the second pressing operation. Otherwise, there would be of no greater projection of the end portions 29 into the blank in the second pressing operation than in the first. As in the case'of the rings 33 and 35, only a single annular member 40 may be employed if desired or if it be more convenient, or other means suitable for such spacing of the shoulders may be used. In any case, the spacing of one or both of the shoulders 30 from the ends of the blank in the first pressing operation, or in other portions 29, results in only partial extrusion of the branch or from the blank, and the removal thereof permits the completion of such extrusion.

In Figs. 8 to 10 inclusive, there is shown still another modification of the method of this invention, for which a somewhat different press structure is employed. In this instance, the die 22 is used, but the rams are of a double acting type comprising outer tubular members 41 within which closely fit relatively movable plungers 42. The wall thickness of the tubular members 41 corresponds to that of the blank 20, and the size of the plungers 42 is such as to permit a good fit thereof within the blank. Relief recesses 28 may be provided in the ends of the plungers 42 as in the case of the rams 27. The blank 20 is prepared by inserting therein a quantity of filler material 21 equal in volume to the volume of the rough fitting to be formed, again disregarding as previously explained the quantity which may flow relievingly into the recesses 28. The blank is disposed within the die 22 as already described, and the rams moved toward each other, the plunger 42 of each ram being held fixedly projected somewhat forwardly of the corresponding member 41, so that the projecting portions of the plungers 42 correspond to and serve the same purpose as the reduced portions 29 of the rams 27, as will be evident from Figs. 8 and 9. The rams are moved toward each other with the respective members 41 and 42 thereof locked or otherwise held against movement relative to each other to effect engagement of the ends of the members 41 against the ends of the blank for shortening thereof to the desired rough fitting length and engagement of the projecting portions of, the plungers 42 against the tiller material within the blank for extruding the partially formed branch 32 into the recess 25 simultaneously with the blank shortening. Upon the rams reaching the position shown in Fig. 9, corresponding to the shortened blank length, movement of the tubular members 41 is stopped so that no further pressure is applied thereby to the blank, and at the same time the plungers 42 are freed from their fixed relation to the members 41, and pressing movement thereof is continued to apply the required pressure to the material 21 for extruding the branch to its full desired extent, or in other words to form the complete branch 34, as shown in Fig. 10. At this point, movement of the plungers 42 is also halted and the rams thereupon retracted, the die 22 opened, and the rough fitting removed and any desired finishing operations performed thereon. It will be understood that at the stage illustrated in Fig. 9, the movement of the plungers 42 may be halted temporarily, and resumed when desired.

The method of this invention results in a thickening or build-up of the wall of the blank or rough fitting opposite the branch, as shown generally at 45 in Fig. 11 in full lines. Similarly, the prior method as generally disclosed in the aforementioned patents produces a thickening or build-up which is indicated generally at 416 by the dotted line in Fig. 11, and which it will be noted is considerably greater than the build-up produced by the method of this invention. It will be understood, of course, that the buildup is not always the same in either method, and that for purposes of clearaness the buildup 46 has been some what exaggerated. Generally speaking, however, the prior method produces a greater build-up than the method of this invention, and in some cases, in order to prevent constriction of the flow passage through the fitting to a point which will not be objectionable in service and meets test requirements, the fitting has to be bored or some other suitable operation performed to reduce the projec- 7 tion of the thickened portion within the fitting. By reason of the generally lesser build-up resulting from the use of the method of thisinve'ntion, such additional operations are required far less frequently and the time, labor, and cost involved in providing fittings meeting test requirements is correspondingly reduced.

Fig. 12 shows in full lines a typical partially formed branch 32, andin dotted lines a typical fully extruded branch 34, of the rough fitting resulting from the pressing of the blank 20. It will be noted that the radius of the portion 47 connecting the side and end walls of the branch is considerably sharper in the branch 34 than in the branch- 32, the side wall or cylindrical portion of the branch being lengthened so that it will be of the desired height or length when the end portion is removed to open the branch in providing the finished fitting, as by severance in the plane indicated by line S.

In the forming of the branch 34 from the partial branch 32, the cylindrical wall portion of the branch is thinned somewhat as the material of the blank is forced into almost full contact with the surfaces of the die recess 25 by the pressure of the filler material 21 on the connecting portion between the end and side walls of the branch.

Such slight thinning is negligible and does not cause weakness in the branch, since the wall thickness of the blank in this general type of forming method is more than suificient to allow of such thinning and yet provide the necessary wall thickness in the fitting. Furthermore, the flow of material of the blank into the recess 25 under the endwise pressure on the blank and the radial pressure of the filler material in the initial pressing operation of the disclosed method appears to result in maintaining the wall thickness of the partially formed branch the same as the initial wall thickness of the blank, or even to increase it somewhat. This of course is consistent with the lesser build-up resulting from the method.

The method of this invention, probably because the blank is not subjected to undue stressing by simultaneous complete extrusion of the branch and shortening of the blank to the desired length as in prior methods, results in a lower proportion of break-outs, or failures of the blank under pressure during the forming thereof. This of course avoids loss through scrapping of material and waste of time and labor.

While several modifications of the method of this invention have been disclosed herein, these are presented as illustrative and exemplary, and it is not intended that the invention be limited to the specific procedures described and illustrated, since variations and modifications thereof may be made without departing from the spirit and scope of the invention.

We claim:

1. A method of forming branched fittings from tubular blanks, comprising the steps of introducing into a tubular blank a volume of substantially incompressible plastic filler material less than the volume of the rough fitting to be formed, then restraining the blank against lateral expansion except at an area at which a branch is to be formed thereon, longitudinally pressing the blank and filler material while so restrained to shorten the blank to a predetermined length and simultaneously extruding a portion of the blank into a partially formed branch at said area of less volume than the complete branch to be formed, discontinuing said pressing and augmenting the filler material in the blank by addition of incompressible material in a volume corresponding to the difference in volume of the partially formed branch and the complete branch to be formed, and subjecting only the filler material and augmenting material to pressure endwise of the shortened blank while maintaining said restraint to complete extrusion of the branch.

2. A method of forming branched fittings from tubular blanks, which comprises inserting a quantity of substantially incompressible plastic filler material in a tubular blank, then restraining the blank against lateral expansion except at an area of branch formation, shortening the blank to predetermined length and simultaneously extruding a portion of the blank into an incomplete branch at said area by endwise pressing of the blank and filler material therein while so restrained, discontinuing said pressing and augmenting the filler material by addition of incompressible material in predetermined volume, and while maintaining said restraint subjecting only the filler material and augmenting material to pressure endwise of the shortened blank to complete extrusion of the branch.

3. A method of forming branched fittings from tubular blanks, comprising the steps of placing in a tubular blank a volume of plastic filler material less than the volume of the rough fitting to be formed, then restraining the blank against radial expansion except at an area at which a branch is to be formed, longitudinally pressing the blank and filler material while so restrained to shorten the blank to a predetermined length and simultaneously extrude a portion of the blank into a partially formed branch at said area of less volume than the complete branch to be formed, discontinuing the pressing and adding to the filler material in the partially formed blank a predetermined volume of filler material corresponding to the difference in volume of the partially formed branch and the complete branch to be formed, and while maintaining said restraint subjecting only the filler material as augmented to pressure endwise of the shortened blank to complete extrusion of the branch.

4. A method of forming branched fittings from tubular blanks, comprising the steps of placing a quantity of plastic filler material in a tubular blank, then restraining the blank against radial expansion except at an area of branch formation, shortening the blank to predetermined length and simultaneously extruding a portion of the blank into an incomplete branch at said area by endwise pressing of the blank and filler material therein while so restrained, releasing the pressure and augmenting the filler material in the shortened blank by adding a predetermined qunatity thereof, and subjecting only the filler material as augmented to pressure endwise of the shortened blank to complete extrusion of the branch while maintaining said restraint of the blank.

5. In the method of forming branched fittings from tubular blanks in which a flowable substantially incompressible filler material is inserted in a tubular blank, the blank then restrained against lateral expansion except at an area at which a branch is to be formed, and the blank and filler material pressed longitudinally during such restraint to shorten the blank to predetermined length and extrude a portion of the blank into a branch at said area, the improvement comprising initially inserting in the blank a quantity of filler material of less volume than required for full formation of the branch by said longitudinal pressing of the blank and filler material terminating upon attainment of said predetermined shortened blank length, discontinuing said pressing upon said short- I ening of the blank to leave the branch only partially formed, then adding a quantity of fillermaterial corresponding in volume to the difference in volume of the partially formed branch and the complete branch to be formed, and while applying said restraint pressing only the filler material as augmented endwise of the blank to form the branch completely.

6. The subject matter of claim 2, the said step of adding an incompressible material in predetermined volume consisting of inserting between the filler material and a pressing means projectable into the blank removable auxiliary pressing means of predetermined volume corresponding in difference in volume of the incomplete branch and the complete branch to be formed.

7. The subject matter of claim 2, the said step of add: ing the incompressible material in predetermined volume providing for such addition being inserted outwardly of References Cited in the file of this patent UNITED STATES PATENTS Murray Nov. 8, 1932 Wendel Nov. 29, 1938 Arbogast June 19, 1951 Wurzburger July 15, 1952 Leuthesser et al July 19, 1955 FOREIGN PATENTS Great Britain 1937 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent NO. 2,975,510 March 21, 1961 Henry Co Heuss et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said:Letter s Patent should read as corrected below.

Column 3, line 56, for apperent" read apparent =3 column 5, line 45 for "if" read of column 6 line 8 before "portions" insert words relative retraction of one or both of the reduced same column 6 line 68 for "clearaness read clearness "-w Signed and sealed this 15th day of August 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

Images