Патент USA US3072096код для вставки
Jan; 8, 1963 J. R. BIRCHFIELD ET AL 3,072,086 METHOD AND APPARATUS FOR FORMING CONICAL AND RELATED SHAPES Filed April 14, 1958 4 Sheets-Sheet 1 E79”! 33 29 F457. 5 24 - 2o 3-2 LIVE ILZQ 7"5> (/5192? E. Bade/weld 2 Var/an A. ?zz/aim Jan. 8, 1963v J. R. BIRCHFIELD ETAYI. 3,072,036 METHOD AND APPARATUS FOR FORMING CONICAL AND RELATED SHAPES ' Filed April 14, 1958 4 Sheets-Sheet 2 29 gig: Lye ILZUT'E Jan. 8, 1963 J. R. BIRCHFIELD ‘ET AL 3,072,086 METHOD AND APPARATUS FOR FORMING CONICAL AND RELATED SHAPES ' Filed April 14, 1958 4 Sheets-Sheet 5 ' 229.5 23 2227.10 é¢ 42 f / ‘4 57 / / / 47 45 gg ?g a? .ELL/E ZZZ-UTE‘ dbfzzz Z8. Birch/422M Jan. 8, 1963 J. R. ‘BIRCHFIELD ET Al. 3,072,086 METHOD AND APPARATUS FOR FORMING CONICAL AND RELATED SHAPES Filed April 14, 1958 4 Sheets-Sheet 4 Egn/j he ?zbr's bLi/FQLJZMMW cfa/m E. Eire/2292M Var/a2; A. Gu/amzl H17‘??? United States Patent 0 " 3,072,086 Patented Jan. 8, 1963 2 l FIGURES 5 and 6 are sectional views of the mandrel 3,072,ti86 structure of FIGURE 4, and showing successive steps of METHOD AND APPARATUS FQR FORMiN-‘G (IONICAL AND RELATED SHAPES John R. Birchtield, ‘Wiclrli?e, and Vartan A. Gulaian, East forming the shape thereon; FIGURE 7 is a sectional view of a modi?ed form of mandrel drive means; FIGURE 8 is a sectional view of another embodiment of the invention, illustrating a mandrel and slidable car rier arrangement by means of which a flat metal blank (Ileveland, Ohio, assignors to Thompson Ramo Wool dridgc, Inc., a corporation of Ohio Filed Apr. I4, 1958, Ser. No. 723,260 8 Ciainrs. (El. 1l3--52) may be initially formed; The present invention relates broadly to the art of 10 FIGURES 9 and 10 are views in section of the same structure as in FIGURE 8, and showing successive steps in the step of FIGURE 10; novel method and apparatus for shaping essentially ?at FIGURE 11 is a side elevational view, partly in sec metal surfaces into conical and related con?gurations. tion, and showing a mandrel construction upon which the Hollow metallic bodies of general conical con?gura tion are employed in various applications, and a typical 15 partially formed shape from FIGURE 10 may be ?nished in accord with the present invention; and environment for such shapes is in rocketry as the nose FIGURES 12 and 13 are views in section of the mandrel section of an airborne article. The preferred practice is arrangement of FIGURE 11, illustrating the ‘manner of to form the conical member by shear spinning, which is successively forming a conical shape to the ?nal con?gura also referred to in the art by the terms of roll forming, tion desired. hydro-spinning, ?oturning, rotary extruding and spin metal forming, and is more particularly concerned with a Brie?y stated, the invention herein disclosed is practiced by arranging a sheet metal shape having an essentially forging. However, present techniques of spinning by use of rotat ing shaped mandrels have been de?cient since it has been ?at face in abutment with an axially immovable rotatable cone-shaped forming surface, the mid-point or center of impossible to produce a true conical article thereon. One approach heretofore taken has been to utilize a blank pro 25 the ?at face coinciding with the central axis or generatrix of the conical forming surface. The forming surface is vided with a central opening, and after imparting an open splined or otherwise secured to a rotatable shaft carrying ended generally conical shape thereto, suitably secure a thereon an axially movable member to which the periph pointed tip to the shape. An alternative method often ery of the sheet metal shape is attached. To assure employed is to form a solid ?at blank into a frustro-conical con?guration, remove the closed end from the shape 30 relatively free axial movement of said member, it is pre ferred to employ a helical splined shaft or straight recir thus formed, and thereafter attach a conical tip thereto. culating ball splined shaft. Rotative movement of the The de?ciencies of each of these laborious methods of shaft causes simultaneous rotation of the sheet metal producing a sharp~pointed conical article are immediate shape and travel of the axially movable ‘member to form ly apparent to those versed in the art. It is therefore an important aim of the present inven 35 said shape to a ?nal conical con?guration having a rela tively sharp vertex produced by the cone-shaped forming tion to provide methods of forming conical shapes in which the tip or vertex portion is formed integrally with the surface. Speci?c details of the additional novel features of the present inevntion will be particularly pointed out as the description proceeds. main body portion thereof. Another object of the invention lies in the provision of apparatus by means of which a metal body of gen erally conical con?guration having an integral nose por tion may be shaped without resort to prior art welding and similar techniques. Another object of this invention is to provide a sheet metal forming method and means constructed to impart 45 Referring now to the drawings, and ?rst to FIGURES 1 to 3, there is shown a structural embodiment effective to initially form an essentially flat metallic sheet into a gen erally frustro-conical shape, which is subsequently proc of a relatively simple and effective means upon which a essed into a sharp-pointed cone con?guration employable as produced for rocket noses, ?xtures and the like. A lathe-type mechanism of conventional construction utilized in the shear spinning art may provide the supporting and motivating functions of the arrangement of FIGURES l and 3, and as shown therein, a mandrel 20 of essentially metal shape may be essentially simultaneously spun and frustro-conical shape provided with a radially outwardly a generally conical shape to a single blank essentially en tirely by metal drawing or spinning techniques. A further object of the invention lies in the provision extending ?ange face 21 is secured to a face plate 22 form ing a part of the lathe head stock portion generally con?gurations. designated by the numeral 23. A further object of the present invention is to provide The head stock portion 23 is normally constructed to a mandrel structure of the con?guration ?nally desired on the blank to be formed and which is axially movable 55 include a driven shaft 24 threaded at one end to receive a collar portion 25 of the face plate 22, and upon which while supporting the blank for rotative movement thereon. is carried an annular spacer 26 hearing against a pulley 27 Other objects and advantages of the invention will be positioned in abutment to a ?ange port ion 28 on a rela come more apparent during the course of the following tively large diameter portion 29 of the head stock 23. description. particularly when taken in connection with the moved axially to form the same into conical and related accompanying drawings. 60 Rotative movement for the spinning operation is imparted to the head stock and the mandrel 20 secured thereto by In the drawings, wherein like numerals are employed to designate like parts throughout the same: a belt 30 trained over the pulley 27 and connected to a suitable power source. The mandrel 20 presents a right frusto-conical con FIGURE 1 is a side elevational view of a mandrel ar rangement upon which a metal blank may be initially formed; 65 ?guration in the form shown; however, conical shapes of the ogive type and others are within the contemplation of this invention, as well as certain other geometrical forms of FIGURE 1, and showing successive steps in the initial requiring a relatively sharp terminex and susceptible to forming of the conical shape thereon; shear spinning techniques as herein disclosed. The man FIGURE 4 is a side elevational view, partly in section, and showing a mandrel construction upon which the par 70 drel construction may vary within the skills of those versed in the art, and accordingly, may be essentially solid tially formed shape from FIGURE 3 may be ?nished into throughout, or may be provided with a conical cavity 31 a sharp-pointed conical con?guration: ' FIGURES 2 and 3 are sectional views of the mandrel 3,072,086 4 :37 therein as appears in FIGURES 2 and 3. Further, the composition of the mandrel may be steel, or for certain this action is a lip or ?ange c on the frustro-conical shape‘ 39 of‘FIGURE 3. applications aluminum alloys and the like, and reinforced plastics may be found suitable, depending upon the The shape 39, as obtained from the last described pre liminary forming step, is further characterized by an end strength and gauge of the material to be formed thereon. - In any event, however, the mandrel 20 is freely sup ported at one end by reason of securement of its base 21 to the face plate 22. The base 21 and plate 22 are at tached in face-to-face relation, each presenting an essen wall or surface 0! of essentially the same thickness as the blank material 33, and of the same generally ?at con?gura tion as the end face 32 of the mandrel 20. Many applica~ tions require that the conical shape have a sharp-pointed nose portion, and one prior art practice has been to re move the end surface d by a cutting operation, and weld tially ?at surface, and bolts or similar meanstnot shown) may beemployed for this purpose. Opposite the base 21 or otherwise secure a separately formed nose portion to the open-ended frustro-conical shape. This practice, as well as the other earlier mentioned conventional approach base to present a frusto-conical shaping surface. of employing a blank with a central opening therein, are Against the flat end face 32 of the mandrel is located a 15 clearly not economical from a time and material stand point. blank 33 to be formed, and the means to maintain said blank in-tight abutment with said face is preferably a Applicants have discovered that the entire body of a pressure pad 34 or its equivalent against which an axial sharp-pointed conical shape may be formed by extruding’ the mandrel is provided with an essentially ?at face or end surface 32,, the plane of which is generally parallel to the forcev is applied by a tail stock portion 35 of the lathe or drawing techniques, and apparatus of proven effective mechanism. The pressure pad is preferably arranged with 20 ness in ?nally shaping the article of FIGURE 3 is illus its mid-point or center in alignment withthe radial center trated in succeeding four views of the present drawings. Turningnow particularly to FIGURE 4, there is again of the blank 33, or stated otherwise, all portions of the assembly shown in FIGURE 1 are axially arranged upon employed a conventional lathe mechanism having a head' stock assembly 23 as described in connection with FIG a common horizontal center line to assureproduction of a shape conforming to the exact contours of the man URE l, and like numerals designate this portion appear ing in FIGURE 4. There is provided in this embodiment of the invention a helically threaded shaft 4%} supported byv drel 20. To provide aright frusto-conical shape, for which the mandrel of FIGURE 1 was particularlyv designed, the blank 33 is essentially circular. However, variations from av straight or right conical con?guration will, of course, an integral collar 41 upon the shaft 24 of the head stock portion 23 and rotatable therewith. Formed at the oppo 30 site end of the helical shaft 40 is an axially immovable normally demand a blank of other than a round circum ference. The material of, the blank or workpiece will vary the shaft 40 is a mandrel 4-3 of generally frustro-conical' conical shaping surface, 42, and axially‘ movable upon con?guration. depending upon the end application, and in addition to sheet materials of aluminum, steeland the like, it is pos— s'ible to shape partially cured thermosetting resins into It is of importance that discontinuities be prevented in the shape of the ?nal article produced by practice of the steps illustrated in FIGURES 4, 5 ‘and 6, and it has been found in this connection that relatively free axial move sharp-pointed cones utilizing the principles of this inven tion. Further, a fully cured resin, such as phenol formal dehyde, may be shaped to conform to the contours of ment of the sliding mandrel 43 is required. Astraight‘ the’mandrels herein disclosed by applying heat to said splined shaft is characterized by heavy bearing forces on mandrels and by use of post-forming techniques known 40 the driving contact faces ofthis type shaft, with the resultv to the art. The most important present application of this, that relatively heavy friction resists axial movement of the mandrel. It is for this reason that a helical splined invention, however, lies in the spinning of sheet metal parts. shaft as shown in the drawings is preferred, although as Rotation of the shaft 24 causes similar movement of the will be noted when reference is madeto FIGURE 7, a mandrel‘ 20 and blank 33 positioned‘ thereagainst, and straight recirculating ball spline also, provides an effective to conform said blank in an extruding manner to the con solution in accomplishing free axial movement. The angle tours of the mandrel, a pressure surface 36 is applied thereto as appears in FIGURES 2 and 3. This surface may, be in the form of a free rotating wheel carried upon‘ a shaft 37 supported at its opposite end upon the lathe’ mechanism for circumferential travel about the mandrel. 20. The path of travel of the pressure wheel 36 is pref erably begun ata point on the blank 33 between the outer diameters of. the mandrel ?at‘ face 32 and pressure pad of the helical spline or continuous buttressthread 44 on the shaft 40 is designed to give a controlled and uniform axial force to the mandrel 43 by contactrwith a continuous mating groove 45 out along the inner diameter of said mandrel. The angle and ?nish of the spline 44 substan tially eliminate the heavy resistant friction between the groove 45 and the spline 44 to allow the mandrel 43 to rotate slower than the shaft 40 and move axially thereof. The mandrel 43 is preferably of a solid and durable metallic construction, and one of the hardened, steels is suitable for the present purposes‘. The shape of the man 34,- and designated generally by the legend a. The travel of the wheel or surface conforms to the contour of the mandrel 20 and proceeds. both circumferentially there about in pressing contact with the blank and longitudinally thereacross to extrude the original metal thickness by kneading operation whereby said metal is spread along the mandrel contours and the thickness thereof reduced progressively during the steps of FIGURES l, 2 and 3; To assure optimum results, the pressure surface 36 longi tudinally traverses the blank along a plurality of overlap ping paths extending circumferentially around the man drel 2t}. 7 Viewing again FIGURE 2, it may be seen that during" rotative movement of the mandrel 20 and the blank 33 securedthereto, the pressure wheel 36 by its circumferen tial and longitudinal travel rolls rearwardly and extrudes a- portion b of generally the original thickness of said blank‘ until substantially the entire contour of the mandrel has drel is frustro-conicahas shown, and includes a generally ?at end surface 46 disposed in“ parallel relation to a radi 60 ally outwardly extending base flange 47 formed integral with the opposite end of the mandrel. In its extreme or starting position upon the splined shaft 40, the mandrel 43 abuts against the cone-shaped forming portion 42 of the said shaft by contact between the end, surface 46 of the mandrel and a ledge 48 on the cone-shaped portion 42. The partially, formed shape 39 from the step of FIG URE 3 is mounted upon the axially stationary mandrel or cone-shaped surface 42 and axially movable mandrel 43 in the manner shown in FIGURE4. The center or mid-point of‘ the end surface or relatively flat face d of the shape 39 bears against the vertex 49 of the cone-shaped forming portion 42, and the ?ange c of the said shape 39 abuts against a ledge or stepped portion 50 provided at been traversed and metal contact made with a ledge or the junction of the main body portion of the mandrel forwardv surface 38 of the mandrel base 21. Formed by 75 43 and the ?ange 47_ thereof. Clamp means 51 are pro? 3,072,086 6 vided to secure the frustro-conical shape 39 to the mandrel 43. The clamp means may be of the ring-type, or may to the structural arrangements of FIGURES l to 7, that be in the form of individual clamping members spaced circumferentially around the mandrel ?ange 47. a relatively ?at blank into a frustro-conical shape and thereafter by ?ow extrusion or shear spinning shaping the frustro-conical article into the shape of the nature of a. right circular cone. While this process and apparatus Power from a suitable source transmitted through the belt 30 to the pulley 27 of the head stock 23 causes ro the shaping process is performed by ?rst shear spinning have substantial advantages over the prior art, applicants tation of the helical splined shaft 46 and cone-shaped have also discovered that a conical shape having a rela mandrel portion 42 integral therewith. By reason of the tively sharp nose portion may be formed continuously helical spline con?guration of the shaft 40, the mandrel from a ?at sheet metal blank. An illustrative embodi 43 moves freely axially thereupon. Since the frusto ment of this form of the present invention is illustrated conical shape 39 is ?rmly attached to the mandrel 43, in FIGURES 8, 9 and 10, and speci?c reference is now rotative force applied to the splined shaft 40 causes made thereto. rotation of the shape 39 and mandrel 43, although at a Essentially, in this form of the invention there is pro substantially lesser speed than the shaft 40. This arises by provision of the helical spline, and due to its rela 15 vided an internally splined tubular mandrel member 57 axially and rotatively movable upon a helically splined tively lesser rotative speed, the mandrel 43 moves axially shaft 58 supported upon a head stock portion 23 of es along the shaft 40 in the manner of FIGURES 5 and 6 sentially the same construction shown in FIGURES 1 to spin and extrude the blunt nose portion or ?at end and 4. At its opposite end the shaft 58 :is formed with surface d to the thinness desired, and assure conformance of the ?at end surface to the contours of the rotating cone 20 a cone-shaped mandrel portion 59 of essentially the same con?guration shown in FIGURE 4. The tubular carshaped forming surface or mandrel 42, the pressure sur rier. 57 is provided at one end with a radially outward face 36 is provided. During this forming operation, ly extending flange portion 60 and against said portion the metal of the end surface d radially'outwardly of a sheet metal blank 61 is secured along its periphery by its center is de?ected or drawn to a relatively lesser thickness, as appears in FIGURE 6, and as the mandrel 25 clamp means 62. 43 approaches the end of its axial travel, the entire body or shape 39 is extruded or drawn to a uniform wall thick ness, as appears in FIGURE 6. The blank 61 is of essentially circular con?guration, and is secured to the tubular member 57 with its radial center bearing against the vertex 63 of the conical shap ing surface 59, and accordingly, the horizontal axis of As will be appreciated, the contours and lengths of the axially stationary mandrel 42 and axially movable 30 the conical mandrel portion 5h, will be found to pass through the center of said blank. mandrel 43 may be altered to provide a shape different The tubular member 57 is provided along its inner from that shown in the drawings, and the length of the diameter with a continuous helically-shaped groove 64 helical splined shaft 40 modi?ed to similarly effect de receiving during travel of said member a similarly shaped sired changes in the con?guration of the ultimate article continuous thread 65 formed on the outer diameter of produced. Further, it may be found desirable upon the shaft 58. The tubular member or carrier 57 and occasion to apply a live center cone to the sharp point or vertex 4? of the forming surface 42 during the course shaft 58 are accordingly of the same spline, and the heli of performance of the steps illustrated in FIGURES 5 and 6 to prevent deflection of the mandrel and resist the load applied by the shear spinning tool. cal arrangement shown has been found in actual practice Free axial movement of the mandrel 43 upon the splined shaft 40 has been found to prevent discontinuities in the shape of the ?nished piece as formed by the ?nal shaping step of FIGURE 6. While successful results have been obtained in practice with the structural em bodiment of the present invention illustrated in FIG URES 4, 5 and 6, particularly conditions may indicate the desirability of also applying a tensile force to the frustro-conical shape 39 during the forming operation as a further assurance that a smooth contour will be achieved in the ?nal article. Further, as a substitute for a helical splined shaft there may be employed a straight to assure free axial movement of the tubular carrier on the shaft. It is to be anticipatedthat a straight spline would be disadvantageous in this application because of the heavy bearing forces on the driving contact faces, and the heavy friction which would result to resist axial movement of the slidable tubular member 57. As in the earlier described embodiment of the invention, a straight recirculating ball spline could be employed as a substi tute for the helical spline of FIGURES 8, 9 and 10. In addition, should particular conditions require that addi tional axial force be applied to conform the blank 61 to the precise contours of the cone-shaped forming surface 59, spring means or hydraulic cylinders or other equiva lent arrangements may be employed. As noted, the shaft 58 is supported at one end by the recirculating ball spline, and a construction of this head stock portion 23 of a lathe mechanism, and rotative character is shown in FIGURE 7. In this embodiment of the invention, a mandrel 56 moves axially in rolling 55 force is applied thereto by belt means 30 connected to a suitable power source. Rotation of the helical spline contact with a plurality of round elements or ball 53 shaft 58 causes a reduced speed rotation of the tubular traveling in continuous grooves 54 formed in a shaft member 57 and sheet metal blank 61 attached thereto, 55. The spline of FIGURE 7 is relatively straight, and and an axial movement of said tubular member or carrier in the event that slight axial resistance to movement is rearwardly along the splined shaft 58 to shear spin the encountered under certain conditions, spring means or blank 61 upon the sharp-pointed axially immovable man hydraulic force may be used to maintain the desired drel 59. To extrude the sheet metal of the blank to the tension on the shape or workpiece 39. Rotation of the thinness desired, and assure conformance of all portions shaft 55 causes relatively slower rotative movement of of the blank to the mandrel contours, a pressure surface the mandrel 56 upon the revolving and circumferentially 66 of the same character shown in FIGURES 2 and 3 traveling ball elements 53, and due to its relatively lesser speed of rotation, the mandrel 56 moves axially upon the shaft 55 to shear spin the shape 39 onto the conical is preferably employed. This may again comprise a wheel mounted upon a shaft 67 and associated with the lathe mechanism for free rotation axially and circum ferentially upon the blank being formed to the contour ?guration shown in FIGURE 6. Recirculating ball con 70 of the mandrel 5%. Travel of the pressure surface or structions are known to the art, and a plurality of ball wheel 66 is initiated radially outwardly of the blank mid elements 53 are arranged in the grooves 54 spaced cir~ point and generally at the location identi?ed by the legend e in FIGURE 8. cumferentially around the shaft 55 in accordance with As the mandrel 59 is spun rotatively and the pressure customary practice. -- .Itmay be seen from the foregoing description, directed 75 surface 66 caused to travel thereabout, axial movement forming surface 56a and into essentially the same con 3,072,086. 8 7 of the tubular carrier 57 with the blank 61 attached thereto spins or draws the blank into exact conformance with the contours of the mandrel 59, as shown in FIG circular surface to the ‘mandrel ?ange with. the radial URE 9, and the progressive spinning operation continues for simultaneously rotating the shaft and moving the until the carrier reaches the end of its path of axial travel. The portion or periphery of the blank 61 clamped to the collar or ?ange 60 of the carrier 57 remains attached mandrel therealong to rotate the surface and axially ex trude the same into conformance with the contours of the thereto, and there is formed at the base of the shape 68 a radially extending ?ange f, as shown in FIGURE 10. center of said surface abutting the vertex of the conical shaping member, and means mounted on the apparatus» conical shaping member. 2. Apparatus for forming essentially conical shapes, comprising a splined shaft supported at one end and pro The ?ange f may be reduced in diameter or entirely 10 vided at its opposite end with a conical shaping member, a substantialiy frustro-conical shaped mandrel member trimmed from the shape 68, and said shape utilized as threadably mounted upon the shaft for axial travel there a rocket nose or the like. The article produced by prac along and having a base ?ange, means for clamping the tice of the invention shown in FIGURES 8, 9 and 10 is essentially a right circular cone, and it will be ap base of a preformed frustro-conical metal shape to the base of the mandrel member, and means rotating the preciated that by changes in the shape of the mandrel 59, other types of conical shapes may be produced. How shaft and essentially simultaneously moving the mandrel ever, it is to be noted that there is now provided a continuous shaping operation whereby the ?nal article member and shape attached thereto axially away from the conical shaping member to spin the shape into contact desired is obtained without resort to independent form therewith. ing operations and welding steps, as has characterized ~ the prior art approaches. In certain cases it may be found that the base diameter of the shape 68 is greater than desired, and to reduce this diameter said shape may be transferred to a mandrel construction of the character shown in FIGURES 11, 12 and 13. As appears therein, the shape 68 may be held against the vertex of a conically-shaped mandrel 69 by means of a formed pressure pad 70. The mandrel 3. Apparatus for forming essentially conical shapes, comprising a splined shaft supported at one end and pro vided at its opposite end with a conical shaping member, a tubular mandrel member threadably carried by the shaft for free axial movement therealong, means attaching the periphery of a disk blank to one end of the tubular member with its radial center abutting the vertex of the conical shaping member, and means rotating the shaft, conical member and blank and essentially simultaneously axially moving the mandrel member to extrude the disk 69 is provided with a radially extending base ?ange 71, and is carried at one end by the head stock portion 23 30 blank against the conical member. of a conventional lathe mechanism in the same manner as earlier described. A free rotating pressure surface '72 carried upon a shaft 73 associated with the lathe mecha nism is provided for axial and circumferential travel 4. Apparatus for forming essentially conical shapes, comprising a substantially straight splined shaft and a plurality of recirculating ball elements movable there along, a mandrel member threadably mounted upon the about the shape 68 to shear spin the ?ange 1‘ into contact shaft in contact with the ball elements and axially mov with the contours of the mandrel 69 in essentially the manner shown in FIGURES 12 and 13. During this cal shaping surface integral with one end of the shaft, a particular shear spinning operation, the ?ange 1‘ is ex truded by the kneading action of the pressure surface 72 continuously rearwardly along the mandrel 69 until contact is made with the base flange 71 of said mandrel 69,. During this secondary shaping operation, the base diameter of the shape 68 is reduced and the body of said shape substantially elongated to provide the ?nal shape 74 of FIGURE 13. It may be seen from the foregoing that applicants have provided mandrel arrangements and shaping methods. which entirely avoid each and every noted dis advantage of the prior art procedures. Each mandrel disclosed is of relatively simple construction, and the . results obtainedv therefrom are of predictable and ex tremely close accuracy. By simultaneously applying ro tative and axial movement to the relatively flat blank, all portions are evenly and continuously extruded into close ?tting contact with the cone-shaped mandrel por tion of the splined shaft. The apparatus disclosed is capable of various modi?cations, as by use of a straight recirculating ball spline, and for particular applications, able along the path of travel of the ball elements, a coni generally circular blank positioned in contact with the conical shaping surface, means clamping the blank to the mandrel member, and means rotating the shaft and essentially simultaneously moving the mandrel member along the path of travel of the ball elements to spin the blank into conformance with the contours of the conical shaping surface. 5. Apparatus for forming essentially conical shapes, comprising a substantially straight splined shaft and a plurality of recirculating ball elements movable there along, a generally frustro-conical mandrel member thread ably mounted upon the shaft in contact with the ball elements and axially movable along the path of travel of said elements, a conical shaping surface integral with one end of the shaft, a substantially frusto-conical me tallic shape supported upon the mandrel member with its end wall in contact with the conical shaping surface, and means rotating the shaft and essentially simultaneously moving the mandrel member along the path of travel of the ball elements to spin the end wall of the shape into conformance with the contours of the conical shaping surface. the addition of means to exert a more positive axial force 6. Apparatus for forming essentially conical shapes, upon the blank to be formed. A wide variety of shapes 60 comprising a threaded shaft supported at one end and may be produced, and materials of different compositions provided at its opposite end with a conical shaping mem and thicknesses may be readily formed thereon. ber, a mandrel member threadably carried by the shaft It is to be understood that the forms of the invention for free axial movement therealong, means for securing herein shown and described are to be taken as preferred a workpiece with a generally ?at circular surface to the embodiments of the same, and that various changes and mandrel member with its radial center in contact with modi?cations may be effected in the size, shape and ar the vertex of the shaping member, and means mounted on rangement of parts without departing from the spirit the apparatus for rotating the shaft and circular surface of the invention or the scope of the subjoined claims. and means for pressing the ?at surface against the conical We claim as our invention: shaping member whereby said mandrel member will move 1. Apparatus for forming essentially conical shapes, axially away from the conical shaping member and pull comprising a splined shaft supported at one end and pro said workpiece to accommodate conforming of said sur vided at its opposite end with a conical shaping member, face to the shape of said member. a mandrel member having a ?ange at one end and thread 7. The method of making cone shapes from workpieces ably mounted‘ upon the shaft for circumferential and axial having non-conical surfaces which comprises, threading travel- therealong, means for clamping a generally ?at a comically nosed shaft through an axially shiftable man 3,072,086 10 during the rotation of said shaft whereby the mandrel will move axially away from the conical shaping member and pull the workpiece to conform to the shape of the conical shaping member. drel, securing the periphery of a workpiece to said axially shiftable mandrel with the shaft nose bottomed on the central portion of said surface of said workpiece, driving the shaft to rotate the mandrel and workpiece, pressing a pressure surface against said rotating workpiece surface for spinning the surface toward the nose, simultaneously rotating the threaded mandrel relative to the shaft for moving the mandrel axially away from the nose, and pull ing the periphery of the workpiece with the axially shift References Cited in the ?le of this patent UNITED STATES PATENTS ing mandrel for drawing the workpiece into conformity 10 with the nose. 8. Apparatus for forming essentially conical shapes, comprising a threaded shaft supported at one end and provided at its opposite end with a conical shaping mem 150,796 1,968,296 2,069,356 2,624,303 2,882,851 2,921,549 Seymour _____________ __ May 12, Hiester ______________ __ July 31, Cooperstein __________ __ Feb. 2, Ghormley ____________ __ Ian. 6, Graves ______________ __ Apr. 21, Schwenk _____________ __ Jan. 19, 1874 1934 1937 1953 1959 1960 her, a tubular mandrel threadably carried by the shaft for 15 OTHER REFERENCES free axial movement therealong, means for securing a Knight’s American Mechanical Dictionary, vol. III, workpiece with a generally flat circular surface to the page 2280, published by Houghton, Mi?lin, and Co., The mandrel member with its radial center in contact with the Riverside Press, Cambridge, Massachusetts, published vertex of the shaping member, means to rotate the shaft, a pressure wheel mounted to press the ?at surface against the conical shaping member, and said pressure wheel caus ing relative rotation between said mandrel and said shaft 0 1884. Metals Handbook, 1948 edition, page 6, The American Society for Metals.