US2685856A - Spun metal manufacture - Google Patents

Description

A. M. WICKWIRE ETAL Aug. 10, 1954 SPUN METAL MANUFACTURE Original Filed Dec. 29, 1949 4 Sheets-Sheet 1 f i It'll] INIZYVTORS i 5 ARTHUR M.WICKW1RE 9'- PAUL WILLIAMS 0 ROBERT J, KILLIAN '9 944444, A; M

ATTORNEYS 10, 1954 A. M. WICKWIRE ETAL 2,635,856

SPUN METAL MANUFACTURE Original Filed Dec. 29, 1949 4 Sheets-Sheet 2 INVENTORS ARTHUR M. WICKWJBE PAUL WILLIAM-8a 5 ROBERT J. KILLIAN '51 ATTORNEYS Aug. 10, 1954' A. MQWICKWIRE ETAL 2,585,856

SPUN METAL MANUFACTURE Original Filed Dec. 29, 1949 4 Sheets-Sheet 3 Fig? 8 INVENTORS ARTHUR M. WICKWIRE PAUL WILLIAMS a ROBERT JJKILLIAN '5' AT TOWEYS Aug. 10, 1954 A. M. WICKWIVRE ET AL 2,685,856

, SPUN METAL MANUFACTURE Original Filed Dec. 29, 1949 l 4 Sheets-$heet 4 lmzvrom ARTHUR M. WMKW/RE PAUL WILLIAMS a ROBERT J. KILLIAN '9 ATTQHVEYS Patented Aug. 10, 1954 SPUN METAL MANUFACTURE Arthur M. lZVickwirev and Paul Williams,v North Canton, andlRobert J. Killian, Canton, Ohio, assignors to'Atlto-matic Steel Products, Ina, Wilmington, Del., a corporation of Delaware Original applicationDecember 29, 1949, Serial No. 135,754.. Divided and this application July 31, 1951,, Serial'No. 239,426

7 Claims.- 1

The invention relates 'tothe precisionmanufacture of one-piece spun metal pulleys, such as V-groove pulleys, from ductile material, preferably rolled steel sheets or strips; and relates more particularly to a method of makinga onepiece pulley from a single metal blank formed with a relatively narrow and relatively deep V-shaped groove therein witha minimum of scrap loss and in accordance with quantity production procedure without sacrificing uniformity offinished product, and this application is a division ofour application for U. S. Letters Patent, Ser.

No. 135,754, filed December 29, 1949. I

More particularly, the present invention eonstitutes improvements upon the methods of malt ing spun metal articles set forth in the Nelson Patent No. 1,688,061, and the HarrisonPatents Nos. 1,828,464; and 2,062,415.

In the manufacture of pulleysin" accordancewith the methods set forth in said prior patents,

a cup-shaped blank is formed froma sheet'metal blank in one of a number of ways, as by spinning or deep drawing; a V-groove is then roller spun Roller spun pulleys are recognized to havemany distinct advantages, such as static and dynamic balance, true concentricity, lightness of weight, maximum strength and durabilityyanddense, smooth, work-hardened and trulyformed roller spun V-groove surfaces. It is'extremely important that these characteristics not-only be" obtained and maintained in the manufacture of such pulleys in large quantities, but that varia---- tions in any one or more of'such characteristics be maintained at a minimum because anysubstantial variation in such characteristics may be cause for rejecting a finished pulley at final inspection.

Certain difficulties have been'encountered in using the methods of pulley manufacture-set forth in said prior patents.

From a practical standpoint it is not'possible in production to draw a flange or annular wall in a cup-shaped blank having a uniform length throughout the extent of the annular fiangewall; Accordingly, it is necessary to allow for excess metal in the cup-flange, as drawn, which excess metal is removed when the finished pulley is trimmed. Also, the non-uniformityof cup-flange length, as drawn, may affect to some-extent uniformity of wall structure. in the V-groove wall adjacent the free. or outer edge of the blank: or pulley, as spun. This factor must be recognized in allowing for excess metal in the cup-flange and in trimming the finished pulley so that the remaining metal in the pulley walls has uniform characteristics.

During the spinning operation, thinning and flow of the metal in the cup-flange wall in which the V-groove ins-formed, cannot be avoided entirely; and this stretching; thinning or fiow of metal in the V-walls for a number of reasons may not occur uniformly. length of the non-uniform length draw-n cupfiange may be one of the causes of non-uniform metal flow when the cup-flange is beingworked. The natural flow of the metal whenthe cup is being Worked by the spinning rolls, and when stretching and thinning may occur, is outward of the open end of the cup, thereby increasing the amount of excess metal in this particular zone, which excess metal is trimmed fromthe-roller spun article to form the finished article; Thus, the amount of metal which must be trimmed,

and which represents a scrap loss, is increased by the spinning operation over that required to be trimmed by reason of the cup forming operation.

The final trimming operation in accordance with prior practice is normally a pinch trimming operation performed in dies'in which the excess metal extending-from the free side wall ofthe V-groove, is removed. Thi trimming operation not only may affect the concentricity of the pulley" but, also, may change the angle or width of the V-groove walls, producing variations in the trimmed pulleys which must be corrected:

Furthermore, the trimming operation results in a trimmed raw metal edge which must be burnished or rounded asan extra operation. Thetrimmed' pulleys then must be trued in respect to concentricityand V-groove angle'and-width in order to provide uniformity in the finished pre- These difliculties have presented a continuing" problem in the art, which, prior to thepresent invention, has remained unsolved. A a consequence the manufacture ofone-piece, spun, sheet metal pulleys involves high costs and scrap losses,

stretching,

Variations in 3 extra operations and handling, and an undesirably large amount of special work in truing defective or rejected finished pulleys.

Accordingly, it is an object of the present invention generally to improve the art of making roller spun V-groove pulleys.

Also, it is an object of the present invention specifically to improve the method of pulley manufacture set forth in the above enumerated prior art patents so as to eliminate the above described difficulties and disadvantages.

Moreover, it is an object of the present invention to provide an improved method of making roller spun, V-groove, sheet metal pulleys so as to obtain a relatively high degree of uniformity and precision in the finished product.

Furthermore, it is an object of the present invention to eleminate trimming as one of the final operations in the manufacture of a roller spun sheet metal pulley.

Likewise, it is an object of the present invention to eliminate the operation of burnishing or rounding the raw edge of a trimmed roller spun sheet metal pulley, and handling thereof incident to such an operation.

Also, it is an object of the present invention to eliminate factors which may cause a change in the angle, or width, or concentricity of a roller spun V-groove pulley after the V-groove has been precision formed therein.

Moreover, it is an object of the present invention to reduce stretching and thinning of the metal in the V-groove walls of a roller spun sheet metal pulley and to obtain uniform metal fiow in the V-groove walls during the spinning operation.

Furthermore, it is an object of the present invention to reduce the amount of scrap loss involved in the manufacture of roller spun, V-groove, sheet metal pulleys.

Also, it is an object of the present invention to substantially reduce the number of rejected pulleys made in the production manufacture of roller spun, V-groove, sheet metal pulleys.

Finally, it is an object of the present invention to provide an improved method of manufacturing roller spun, V-groove, sheet metal pulleys which satisfies the foregoing objects, solves problems existing in the art, obtains unexpected results, reduces costs, and which is simple and convenient to use.

These and other objects and advantages apparent to those skilled in the art from the following description and claims may be obtained, the stated results achieved, and the described diniculties overcome, by the methods, steps, procedures, operations, and combinations which comprise the present invention, the nature of which are set forth in the following general statements, a preferred embodiment of which-illustrative of the best mode in which applicants have contemplated applying the principleis set forth in the following description and shown in the drawings, and which are particularly and distinctly pointed out and set forth in the appended claims forming part hereof.

The nature of the improved method of the present invention may be stated in general terms as including drawing a cup-shape from a single sheet metal blank, preferably a sheet or strip steel blank, trimming excess metal from the annular free edge of the flange of the cup-shaped blank to provide a uniform flange length, roller spinning a V-groove in said flange while confining the trimmed flange edge against radial or axial or outward movement thereby preventing outward flow of the metal in the flange and reducing stretching and thinning of the metal in the V-groove during spinning, and rolling the outer confined trimmed edge of the blank during roller spinning.

By way of example, a preferred embodiment of the method steps of the present invention are illustrated in the accompanying drawings forming part hereof, wherein:

Figure 1 is a diagrammatic sectional view of a flat sheet metal blank from which a pulley may be fabricated in accordance with the invention;

Fig. 2 is a diagrammatic sectional view of a cup-shaped pulley blank drawn from the fiat sheet metal blank of Fig. 1;

Fig. 3 is a similar view of the cup-shaped blank of Fig. 2 after the cup has been trimmed to provide a predetermined uniform length of annular flange;

Fig. 4 is a view similar to Fig. 3 illustrating a V-groove roller spun in the flange of the cupshaped blank of Fig. 3;

Fig. 5 is a fragmentary, diagrammatic, sectional view illustrating the dies for roller spinning a V-groove in the flange of the trimmed blank of Fig. 3 at the beginning of the rough spinning operation;

Fig. 6 is a view similar to Fig. 5 illustrating the spinning dies at the conclusion of the rough spinning operation;

Fig. 7 is a view similar to Fig. 5 showing the roller spinning dies at the beginning of the finish pinning operation;

Fig. 8 is a view similar to Fig. '7 showing the parts in one stage during the finish spinning operation;

Fig. 9 is a view similar to Figs. 7 and 8 showing the parts at the conclusion of the finish spinning operation;

Fig. 10 is an enlarged view of a portion of the finished pulley shown in Figs. 4 and 9; and

Fig. 11 is a View similar to Fig. 9 showing a slightly modified form of pulley shape and spinning dies therefor.

Similar numerals refer to similar parts throughout the various figures of the drawings.

Roller spun V-groove pulleys conventionally are made of sheet or strip metal of say sixteen gauge metal (.065" in thickness) although heavier or lighter gauge metal obviously may be used. Likewise, such pulleys conventionally are made of steel, but obviously may be made of other types of sheet metal. Accordingly, it is understood that the invention is not limited to the particular gauge or type of metal used.

Although a V-groove pulley may be made from a flat sheet metal blank solely by spinning operations, as indicated in the Nelson Patent No. 1,680,061; nevertheless, in the volume production of pulleys, it is preferred to draw, by deep drawing or press operations, a cup-shaped blank or work piece with a cylindrical flange wall in which the V-groove is later formed, and then to spin the V-groove in the flange wall of the cup-shaped work piece by spinning operations.

A flat sheet metal blank is indicated at l in Fig. 1 from which the cup-shaped blank generally indicated at 2 in Fig. 2 is drawn in a press. The cup-shaped blank 2 has the usual characteristic scalloped or wavy edge 3 of a drawn piece at the open or free end or edge of the cylindrical or annular flange 4 of the blank 2. The cupshaped blank 2 also includes a wheel disc portion 5 and may have an annular hub flange 6, the disc portion 5 and hub flange 6 being formed be moved toward and away from the common axis of the head and tailstock spindles 8 and 28. The spinning roll 49 has a working surface generally indicated at shaped in cross-section to have substantially the contour of the V-groove to be formed in the pulley. The working surface 5i comprises an annular rounded nose 52, angled, annular side surfaces 53 angled at angles complementary to the angles of the annular surfaces 24 and 34 on the head and tailstock spimiing dies l6 and 3|, and annular shoulders 54. The spinning roll 49 also may have tapered annular sur-, faces 55 extending from the annular shoulders 54.

The spinning machine of the Harrison Patent No. 2,062,415 on which the improved spinning dies l6 and 3| and spinning rolls 44 and 49 may be mounted for carrying out the improved method of the present invention is constructed so that the headstock spindle 8 may be rotated; so that the tailstock spindle 28 may be moved axially toward the headstock and axial pressure applied between the head and tailstock dies I5 and 3|, the working pressure being effected through air cylinder or hydraulic cylinder means; and so that the rough and finish spinning rolls 44 and 49 may be moved selectively, toward and away from the cooperating spinning dies l6 and 31, by mechanical or hydraulic means.

In accordance with the present invention, the head stock and tailstock spindles 8 and 28 are both driven at the same speed for rotating the same, a usual drive from a common shaft or source of power being provided.

In carrying out the spinning procedure of the present invention, a trimmed blank 2a is telescoped over the pilot pin 2| with its hub flange 6 closely fitting the outer surface of the pilot pin 2|. The headstock and tailstook spindles 5 and 28 are then rotated and the tailstock spindle 28 is moved toward the headstock spindle, the free,

end of the pilot pin 2| entering the opening 32 in the tailstock die 3|. The blank 2a is thus clamped between the driven head and tailstock dies 56 and 3| and rotated therewith, as shown in Fig. 5.

In this clamped position, the outerend edge 55 of the annular flange 4a of the cup shaped blank 2a abuts against the chainfered corner 25 of the headstock die Hi and an annular band at the outer end of the flange 4a of the blank 2a, indicated at 51 in Fig. 5, is confined within and by the overhanging edge 4| of the ring 35. Thus the ring 35 confines and holds the open end of the formed cup in against radial or outward expansion.

With the trimmed cup-shaped blank 2a thus clamped, confined, held and rotated by driven dies |6 and Bi and ring 35, the axis of the rough spinning roll 44 is moved toward the common.

axis of the head and tailstock spindles, as indicated by the arrow 58, until the nose 48 of the roll 44-engages an intermediate surface of the cup-flange 4a. Continued movement of the spinning roll 44 toward the axis of the head and tailstock spindles applies a roller spinning pressure to the flange 4a, thus forming a groove inwardly therein until the spinning roll 44 reaches the limit of its inward movement as illustrated in Fig. 6.

Meanwhile the overhanging edge 4| of the ring 35 has continued to confine and hold the open end 56 of the cup-flange 411 against any radial or outward movement. As the spinning roll 44 moves from the position shown in Fig. 5t0 the;

8-- position shown in Fig. 6, its working surface 46 first engages the angled surface 40 and finally the angled surface 4| of the ring 35 to push the ring axially against the pressure of the springs 31 to the position shown in Fig. 6.

By confining the end 56 of the cup-shaped blank 2a as the semi-finished groove 59 is being formed in flange 411 by the rough spinning roll 44, the natural flow of metal outward of the open end of the cup, as the metal in the flange 4a. is being Worked by, thev spinning roll 44, is restricted; and a more uniform and less thinned metal structure in the groove section 59 is obtained.

While the rough spinning roll 44 is ,moving to the limit of its inward movement shown in Fig. 6, the tailstock die 3| moves to the left from the position shown in Fig. 5 to the position shown in Fig. 6. During such movements, the annular flange 6 of the blank 2a slides along pilot pin 2| and into recess 21 which is provided for receiving the hub flange 6. At the completion of the rough spinning operation, illustrated in Fig. 6, the wheel disc portion 5 of the cup-shaped blank 2a,.although pushed to the left by tailstock die 3|, is still spaced from the right-hand end face of the headstock die i5, as indicated at 69 in Figs. 6 and 7. This condition must exist at the end of the rough spinning operation so that further movement of the disc portion 5 of the blank to the left may take place during the finish spinning operation with the V-groove being formed is deepened and narrowed.

In performing, the rough spinning operation illustrated in Figs. 5 and 6, annular flange 4a of bank 20. collapses inward, so to speak, by the inward pressure of the rough spinning roll 44 and the axial pressure of tailstock die 3|. Due to the character and shape of the rounded working surfaces 48 and 48 of the roll 44, the metal in the flange wall 4a flows evenly and uniformly during the reshaping without any localized pressure which would cause thinning of the metal in the walls of the groove 59 being formed. In fact, because the outer edge 56 of the flange 4a is confined by the ring 35, preventing normal or natural flow of metal outward in the lefthand wall of the groove being formed, the tendency may be to thicken rather than to thin the :metal in the groove wall because of the reduction in diameter thereof.

Referring to Fig. 5, the overhang of edge 4| of ring 35 is substantial so that it is impossible for any portion of the free edge 56 of the cupshaped blank to slip out of the confining pocket formed by the cylindrical abutment shoulder or overhanging edge 4! of ring 35. If the end 56 of the cup-shaped blank were to slip out of a confined position during the rough spinning operation, the benefits of the present invention would be lost because-v there then would be an outward flow of metal in the outer groove wall. which excess metal would have to be trimmed as a final operation, and the metal in the groove walls would not be uniformly worked. '7

Of equal importance in this connection is the fact that the trimmed blank Ed has a flange 4a of absolutely uniform predetermined length. If thereare any variations in the length of the flange 4a, the confining pressure on the flange during the rough spinning operation will be localized at the zone of greatest flange length, thus causing non-uniform working and flow of the metal during the groove formation and creating the possibility of the open end 5.5 of the flange v Jo annes slipping routpfconfinementfby theoverhanging sedge-4H of ringed .rEin-ally, during vithe roughspinning operation, the metalin :the iannularrinner and outer corners "of the :end 1560f the Fflange 14a. is slightly rounded or -.-.deburred as this 'edge 5E and the wall zone ".51 moves or is reshaped from the position or shape shown in Fig. 51110 the' positionorshapershown in .E'igsfiandt'l. This occurs because of the ;pressure :of the ztailstock die lfl and :rough spinning :roll .44 resistedby tapered headstock die -w-all .24, chamferejd :corner '25, :and thein-ner :cylindrical surf-ace 42 of .the ring :35. .lhus these inner and outer cornersof the metaledge wall 5.6, in turning :or rotating on such :clie suriaces under pressure, become slightly rounded.

The spinning roll -44 then moved-away 'from the head and-tail-stockspindlese8and 28 at which time the ring .35, by :the pressure of springs 31, may move hack to :a position .inwhichits shoulder 36 .abuts the shoulder 23 .of the headstock .die t6, and the ?end-4.l of the: ring '35 overhangs the open end edge 60 of (the semi-finished pulley -61 to a maximumiextent, as shownsin Fig. .7. The finish spinningfrollidril-vl lig. .7) :is then moved toward the-rotating semi-finished pulley .61 .in the direction of the arrow .62 shown in Fig. .-'Z,.-and rolls the V-groove 63 from the semi-finished-shape illustrated at 5.9 in Fig.1? to the final finished shape illustrated-at63- Figsdgi) and -.A the T911 49 moves'toward the rotating spinning dies 1 6 and .31., thenose .52 :of the roll Working surface 51 works-the metal in the base of the groove 63.. Meanwhile the-continued pressure of the tailstock die 34. in the direction of the arrow .64 inFigs. 7, 8, and 9 furtheroollapses and narrows the width of the -V--groove, and the roll-sur- Iaces53 iron the metal in the sidewalls of the V.

.As the roll 49 -moves inward, the tapered surface -55i ch the left-side thereof engages the angled surfaces 40 and =44 of the ring 35 and pushesthe ring 35 to the left as illustrated in Fig. 8. Just before X01149 reaches its finalrmetal working position .(Fi g.-:8), the overhanging end 41 of the ring .35 :slips over the end 50 of the semi-finished pulley .64 thereby momentarih releasing confinement or restriction thereof. However, the roll 49 immediately moves further inward in semifmished groove 59 (Fig. 9) to the final predetermined -.depth of the groove, and in so doing, the annularshoulders 54 -:.on the roll 49 engage and work the open .end 460 ofoneV-wall 65. and the outeriedge $6. of the other double thickness metal y-wall 61,. as illustrated in Fig.9.

vAs the spinning .roll :49 reaches its limit of .in-' ward movement .(Fig. 9) it exerts final working pressure on the pulley blank .betweenits working surface 5.! and the-angled .working surfaces .24 and. ofthe spinning dies 16 and BI, and the tailstocli die .34 moves to the limit of itsmovement tothe lei-t, thereby uniformly and finely ironing and working the .metal surfaces. of the finally for-med V-groove 6.3- of the finished pulley .68. During this final working operation of the metal in the ill-groove of the pulley,.the shoulders .54 of the 1 01149 roller work the edges so and .65 of the metaleat theouter end. of the V-shape, thereby rounding theseedg-es insuch manner that no .sep arate finalburnishing operation i required.

-Although it is indicated above that the internal diameter 43 of the overhangingedge of ring.35 is'zof the same diameter .asthe outer diameter of the finished pulley 68, .as a practical .matter .and because of the momentary release of the outer edge 50 of the pulley W-henring. 35 gives way to ime :finish spinning :rollAfi just before the finish spinning roll reaches its limit :of inward move- Fment, this internal diameter is made slightly under-the size of the finished diameter of the -pnlley 68, so that when the. open edge 60 of the pulleymomentarily tends to grow or'fiow or "exepand outward before the roll flare-aches its limit :of inward movement, the shoulders *54 :will roller 'work the 'V-groove wall edges dill and t6 :and finally-size the pulley.

During the working movement of theffinish :spinningroll 49, as illustrated in Figs. 7,"8 and the tailstock die '3 I moves further to the left from v the position shown :inFig. '7 to the position shown in Fig. :9, and the gap lillrdecreases which as the finalposition *of :Fig. -9 is reached.

. During the final spinning operation, the-side walls of the Vagrooveare furither shapedufromthe shape illustrated in Fig. -'7 to that illustrated in Figs. 4, 9 and 10 so .as .to have the desired V- groove angle and width. Atthe same time, the metal in the base of the=groove is further worked inward by the nose 52 6f roll 49, from the position 59 shown in Fig. 7 to the position :63 shown in Fig. 9.

Meanwhile, the overhanging edge '41 of ring 35 continues, until the momentary release previously described, to -:confine the outer edge- B!) of the semi-finished pulley 61 to "prevent outward flow-of the-metal .in the-:outer groove wall and to prevent :any appreciable :or' substantial thinning of the metal in the groove wall. Also, thisconfinement of the edge :60 of the semi-finished pulley til during the 'fini-sh spinning operation continues to prevent the metal walls :loeing worked from slipping :out of the desired :coniined position with respect to the .dies and spinning roll.

The final ironing of the metal surfaces of the formed V-groo-ve t3, just as the roll-'49 reaches its limit of inward movement in Fig. :9, uniformly works and sizes the. shape of the V-groove and'the thickness of the groove-forming metal walls, thus providing 'a finished pulley having static and dynamic balance and truerconcentricity and-having dense, smooth, work-hardened :and truly termed roller spun V-groove surfaces.

Furthermore, as previously indicated, the final ironing operation also works and rounds the edges 63D andtli of the v groove walls by the rolling pressure of the roll 'shoulders'fi l. The rounding for deburring of the edgefifl which was commenced in the rough spinning operation and thus completed .in the .fina-l spinning operation, produces the edge shape illustrated in Fig. 10 wherein the corners m and H of edgefiil. are truly rounded.

A slightly imodined form of pulley shape is indicated, at the outer or *free edge of the V -groove walls. This pulley shape may :be formed in aceordancewith the present invention by slightly modifying the'headstock die It to have a recess 14 for receiving the pulley flange 13 beneath the overhanging edge i confining ring 35 and by modifying the shape of the finish spinning roll 49a. to have a widershoulder 540. at its left-hand side. The modified dies and finish spinning roll illustrated in Fig. 11 operate in the same manner as described in connection with Figs. '7, .8 and 9 except that the ring 3.5 always confines the free endof the pulley blank without the momentary release just before the .finish spinning roll reaches its limit of inward movement describedin connection with Figs. 8 and .9.

In commercial operations involving the use of the improved apparatus and procedure of the present invention to make the improved product described, the novel procedure is commonly referred to as spinning in the ring. This term is used because the open end of the formed cup, which is to be spun, is confined within the mov' able ring 35, located and sliding on the headstock die [-8 of the spinning apparatus. The tapered surfaces 40 and M of the movable ring facilitate movement of the ring by the spinning rolls 44 and 69 as these spinning rolls are working the metal in the pulley blank. The sharper angle of the surface 4 l, with respect to the angled surface 4!] of the movable ring 35, reduces to the last possible split second the time elapsing between the moment that the movable ring releases confinement of the blank edge 89 and the moment when the finish spinning roll d9 reaches its limit of inward movement as shown in Fig. 9.

The improved apparatus and procedures of the present invention accomplish many new results and advantages.

First, since the metal in the pulley blank is confined by the movable ring during the spinning operations, a more uniform and less thinned groove section is obtained.

Second, trimming of excess steel which is present in pulleys not spun in the ring is eliminated. By the elemination of this trimming operation, steel is saved as well as the handling of the spun pulleys in connection with a final trimming operation. Moreover, the elimination of the final trimming operation also eliminates the possibility of distortion of the spun pulley and a change in the belt groove angle or width which may occur when a spun pulley is thereafter trimmed. The elimination of these operations in turn reduce scrap loss, save steel, and eliminate to a large extent the necessity for any standard truing-up operation following spinning. Of course, a final inspection is always used but when pulleys are made in accordance with the present invention, there are only a minimum number of pulleys rejected at the final inspection which must be trued-up to provide a uniform groove, angle or width.

Third, in view of the fact that the outer edge of the confined pulley blank flange is rounded and rolled, as indicated at T and H in Fig. 10, a final burnishing operation is eliminated together with handling of the spun pulley and likelihood of a change of the groove angle or width incident to such burnishing operation.

Fourth, the relative concentricity of pulleys made in production runs in accordance with the present invention is better than in any prior known pulley manufacturing procedure.

Accordingly, the present invention provides general improvements in the art of making roller spun V-groove pulleys; satisfies each and all of the objects set forth in the preamble of the specification; enables the advantages of roller spun pulleys to be obtained in a spun pulley product while eliminating disadvantages and defects heretofore encountered in the manufacture of pulleys by spinning procedures; enables the elimination of final steps of trimming, burnishing, and handling incident thereto; provides for the manufacture of roller spun V-groove sheet metal pulleys with a high degree of concentricity, uniformity, and precision in the finished product and with a minimum of scrap loss and rejected pulleys produced; and solves problems and satisfies demands existing in the art, and obtains the new enumerated unexpected results.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art; because such words are used for descriptive purposes and not for the purpose of limitation and are intended to be broadly construed.

Moreover, the invention is not limited to the exact spinning die and spinning roll structures shown, nor to the exact pulley shape illustrated, because the particular shapes of the dies, rolls and pulleys may be varied to provide other structural embodiments without departing from the scope of the present invention.

Having now described the features of the invention, the construction and operation of pre ferred embodiments of improved roller spinning apparatus, the details of the steps of the improved method, the new spun metal products provided, and the advantageous, new and useful results obtained thereby; the new and useful inventions, constructions, devices, parts, elements, arrangements, combinations, sub-combinations, methods, steps, procedures, operations, discoveries, principles, products, and reasonable mechanical equivalents thereof, obvious to those skilled in the art, are set forth in the appended claims.

We claim:

1. Apparatus for roller spinning a groove in a flange wall of a cup-shaped blank having a predetermined uniform axial flange length including, opposed rotatable headstock and tailstock dies, driving means for rotating each of said dies, means for axially moving one of the dies toward and away from the other, a spinning roll operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, and a ring mounted on one of the dies for rotation therewith having an inner cylindrical axially extending abutment shoulder circumferentially overhanging the annular groove forming surface on said one die, said ring normally being urged axially in one direction relative to said one die and being engaged during rotation by said spinning roll and moved thereby axially in the other direction relative to said one die.

2. Apparatus for roller spinning a groove in a flange wall of a cup-shaped blank having a predetermined uniform axial fiange length including, opposed rotatable headstock and tailstock dies, means for rotating said dies, means for axially moving one of the dies toward and away from the other, a spinning roll operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, a ring mounted on one of the dies for rotation therewith having an inner cylindrical axially extending abutment shoulder circumferentially overhanging the annular groove-forming surface on said one die, said ring normally being urged axially in one direction relative to said one die, and said ring having an annular surface extending outwardly of said cylindrical shoulder engaged duraway from the "other; a spinning roll "operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, a ring mounted on one of the dies for rotation therewith having an inner cylindrical axially extending abutment shoulder circumferentially overhanging the annular groove-forming surface on said one die, said ring normally being urged axially in one direction relative to said one die, and said ring being formed with annular tapered surface means extending outwardly of said cylindrical shoulder engaged during rotation by a working surface of said roll as the roll is moved toward the axis of rotation of the dies to axially move said ring in the other direction relative to said one die.

4. Apparatus for roller spinning a groove in a flange wall of a cup-shaped blank having a predetermined uniform axial flange length including, opposed rotatable headstock and tailstock dies, means for rotating said dies, means for axially moving one of the dies toward and away from the other, a spinning roll opera tively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, an axially movable ring mounted on one of the dies for rotation therewith having an inner cylindrical axially extending abutment shoulder, yielding means urging the ring axially in one direction relative to said one die and normally holding said ring in a position in which said shoulder circumferentially overhangs the annular groove-forming surface on said one die, and said ring being engaged during rotation by said spinning roll and moved thereby against the pressure of said yielding means axially in the other direction relative to said one die.

5. Apparatus for roller spinning a groove in a flange wall of a cup-shaped blank having a predetermined uniform axial flange length including, opposed rotatable headstock and tailstock dies, means for rotating said dies, means for axially moving one of the dies toward and away from the other, a spinning roll operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on for rotation their'ewithv having an inner .cy'l indri deal axially extending abutment shoulder, yield- ;in'g means urging thering axially in -on direction relative-to said onedie and normally holding :said

in a position in which said shoulder circumferentiail ly overhangs the. annular groove-formingssurfacezaon said one die, an annular tapered :surltacezfiormed on said ring, and "said spinning 1 611 engaging said tapered surface during rotation of said ring to move said ring aga'inst' the pressure of said yielding means axially in the other direction relative to said one die as said roll is moved toward the axis of rotation of the dies.

6. Apparatus for roller spinning a groove in a flange Wall of an open-ended cup-shaped blank having a predetermined uniform axial flange length including, opposed rotatable headstock and tailstock dies, means for rotating said dies, means for axially moving one of the dies toward and away from the other, a spinning roll operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and awa from the axis of rotation of the dies, opposed annular groove forming surfaces formed on said dies, working surfaces formed on said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, said spinning roll working surfaces including an annular shoulder engageable with the open end of the flange of a cup-shaped blank as the roll is moved toward the axis of rotation of the dies and as said flange is being worked between said dies and roll, and a ring mounted on one of the dies for rotation therewith having an inner cylindrical axially extending abutment shoulder circumferentially overhanging the annular grooveforming surface on said one die and thereby confining said open end of said blank flange wall against radial outward movement beyond said ring shoulder until said open end is engaged by said spinning roll shoulder, said ring normally being urged axially in one direction relative to said one die and being engaged during rotation by said spinning roll and moved thereby axially in the other direction relative to said one die until said open end is engaged by the spinning roll shoulder during movement of the latter toward said spinning roll cooperating with said die surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies, an axially movable ring mounted on one of the dies the axis of rotation of the dies.

'7. Apparatus for roller spinning a groove in a flange wall of an open-ended cup-shaped blank having a predetermined uniform axial flange length including, opposed rotatable headstock and tailstock dies, means for rotating said dies, means for axially moving one of the dies toward and away from the other, a spinning roll operatively mounted at one side of the axis of rotation of the dies, means for moving the spinning roll toward and away from the axis of rotation of the dies, a tapered annular groove-forming surface formed on said headstock die, an opposed tapered annular groove-forming surface formed on said tailstock die, said headstock die having an outer cylindrical surface and a chamfered corner conmeeting said cylindrical and tapered surfaces, working surfaces formed on said spinning roll cooperating with said die groove-forming surfaces when the dies are rotated and the roll is moved toward the axis of rotation of the dies to roller spin an annular groove in a flange wall of a cupshaped blank held clamped between said dies with the open end of said flange wall engaged by said chamfered corner, and axially extending ieldingly mounted cylindrical shoulder means 15 16 mounted on the headstock die for rotation there- References Cited in the file of this patent with and overhanging said chamfered corner and UNITED STATES PATENTS the open end of said flange wall engaged thereby confining the open end of said flange wall against Number Name Date Outward radial movement, said shoulde m ns 5 259,173 Lali fi June 6, 1882 normally being axially in one direction relative 1,647,843 lth NOV. 1, 1927 to the headstock die and being engaged during 1,680,061 0n Aug. 7, 1928 rotation by said spinning roll and moved thereby 1939356 Lmderen 1933 axially in the other direction relative to said 5 Harrlson Dec. 1, 19 6 headstock die. 10 6 BOhm Apr. 29, 1941 2,247,002 Rendleman June 24, 1941

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