US3908421A

US3908421A - Apparatus for making multi-groove pulleys

Info

Publication number: US3908421A
Application number: US507221A
Authority: US
Inventors: Robert J Killian; Nolte V Sproul
Original assignee: Dyneer Corp
Current assignee: Gates Power Drive Products Inc
Priority date: 1973-10-19
Filing date: 1974-09-18
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

Apparatus for making a V-grooved pulley having at least three grooves from a single cup-shaped sheet metal blank having a cup bottom wall and a cylindrical side wall. A cup-shaped blank first is formed by usual press operations. Then the cup bottom wall preferably is supplied with a hub of desired configuration having an axial bore with which the ultimately formed pulley grooves are concentric and about which the pulley to be formed is dynamically balanced. Two pulley grooves then initially are spun adjacent the cup bottom wall in the cup cylindrical flange or side wall to form an intermediate spun product in special first stage spinning dies. A third pulley groove then is spun in second stage spinning dies in the cylindrical cup side wall between the open end of the cup and the two initially spun grooves. The cylindrical side wall portion of the intermediate spun product in which the third groove finally is formed adjacent the open end of the cup, supports the cup during operation of the first stage dies, while the two grooves initially are formed in the cup, thereby assisting in maintaining concentricity and in providing dynamic balance during groove spinning.

Description

United States Patent 1 Killian et a1.

1 1 Sept. 30, 1975 1 1 APPARATUS FOR MAKING MULTI-GROOVE PULLEYS [73] Assignee: Aspro, 1ne., Canton. Ohio [22] Filed: Sept. 18. 1974 211 Appl. No.: 507,221

Related US. Application Data [62] Division of Ser. No. 407.942. Oct. 19. 1973. Pat. No.

[52] US. Cl. 72/82 1] Int. Cl. B21D 22/16 [58] Field of Search 72/82. 91, 94; 113/116 D; 29/159 R [56] References Cited UNITED STATES PATENTS 2.685.856 8/1954 Wickwire et al 72/82 2.826.804 3/1958 Wiekwire et al... 29/159 R 2.827.225 3/1958 Killian 29/159 R 2.869.223 1/1959 Killian et a1 29/159 R 2.892.431 6/1959 Killian et a1. 72/82 2.929.345 3/1960 Zatyko. Sr. 29/159 3.124.090 3/1964 Zatyko 29/159 3.406.440 10/1968 Trute 29/159 R 3.654.790 4/1972 Zatko 72/82 Prinmry E.\'uminerRichard .I. Herbst Attorney. Agent. or Fim1Frease & Bishop [57] ABSTRACT Apparatus for making a V-grooved pulley having at least three grooves from a single cup-shaped sheet metal blank having a cup bottom wall and a cylindrical side wall. A cup-shaped blank first is formed by usual press operations. Then the cup bottom wall preferably is supplied with a hub of desired configuration having an axial bore with which the ultimately formed pulley grooves are concentric and about which the pulley to be formed is dynamically balanced. Two pulley grooves then initially are spun adjacent the cup bottom wall in the cup cylindrical flange or side wall to form an intermediate spun product in special first stage spinning dies. A third pulley groove then is spun in second stage spinning dies in the cylindrical cup side wall between the open end of the cup and the two initially spun grooves. The cylindrical side wall portion of the intermediate spun product in which the third groove finally is formed adjacent the open end of the cup. supports the cup during operation of the first stage dies. while the two grooves initially are formed in the cup. thereby assisting in maintaining concentric ity and in providing dynamic balance during groove spinning.

11 Claims. 20 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 o 9 3,908,421

CUE

Sept. 30,1975 Sheet 2 of 9 3,908,421.

mdE Q om r Q US. Patent Wm 5 m US. Patent Sept. 30,1975 Sheet4 of9 3,908,421

Sept. 30,1975 Sheet 5 of 9 3,908,421

US. Patent US. Patent Sept. 30,1975 Sheet6 0f9 3,908,421

US. Patent Sept. 30,1975 Sheet7 of9 3,908,421

Sept. 30,1975 Sheet 8 of Q 3,908,421

US Patent US. Patent Sept. 30,1975 Sheet 9 of 9 3,908,421

FlG.l7

APPARATUS FOR MAKING MULTI-GROOVE PULLEYS CROSS REFERENCE TO RELATED APPLICATION This application is a division of our copending application Ser. No. 407,942, filed Oct. 19, 1973, now US. Pat. No. 3,852,863.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to spun dynamically balanced V-grooved sheet metal pulleys in which at least three V-grooves are formed in the cylindrical flange or side wall of a cup-shaped blank and in which the \/-grooves are relatively narrow and relatively deep and have the same configuration.

More particularly, the invention relates to apparatus for performing a series of steps carried out or metal working operations performed in a controlled manner to produce a multi-groove pulley having at least three grooves from a single cup-shaped sheet metal blank without resultant localized stresses in the pulley metal, and wherein the completed product has the multiple pulley grooves concentric with respect to the axial bore in the pulley hub, and wherein the pulley is dynamically balanced,

2. Description of the Prior Art Many procedures for the manufacture of V-groove pulleys either with single grooves or two grooves are known involving rolling or spinning operations or press operations, or combinations of any or all of such operations, during any of which operations the pulley is formed from a single sheet metal blank. Such known pulleys, and methods of and apparatus for making such pulleys are shown in US. Pat. Nos. 2,685,856, 2,826,804, 2,827,225, 2,869,223, 2,892,431, 2,929,345, 3,124,090, 3,406,440 and 3,654,790.

However, insofar as we are aware, no prior apparatus for making V-groove pulleys with more than two V- grooves formed in a single sheet metal blank has been known.

Multiple groove pulleys having more than two grooves have been proposed or used, wherein the grooves have been formed separately in separate sheet metal blanks and the separate grooved intermediate blanks then have been assembled to provide the final grooved pulley product having three or more grooves, such as shown, for example, in US. Pat. Nos. 1,700,416, 1,905,907, 2,008,300 and 2,092,571.

Multiple V-groove pulleys having three or more grooves made from a single metal blank, dynamically balanced and having concentricity maintained between the grooves and the pulley axis, are much to be desired from many standpoints such as decreased metal cost, decreased weight, and the elimination of assembly costs for multiple piece products; as compared with multiple-groove pulleys composed of an assembly of a number of metal parts, each having a V-groove formed therein, as comprehended, for example, in the last enumerated prior art patents.

Accordingly, there has been an existing need for many, many years for apparatus for the successful and economic manufacture of concentric and dynamically balanced multi-groove pulleys having at least three V- grooves formed adjacent one another in a single sheet metal blank.

SUMMARY OF THE INVENTION Objectives of the invention include providing apparatus for performing the procedure for the manufacture from a single sheet metal blank of a V-groove pulley having at least three. grooves therein; providing apparatus including first and second stage spinning dies for the manufacture of such a multi-groove pulley wherein two V-shaped pulley grooves initially are spun in the first stage dies in the cylindrical side wall of a cup adjacent the cup bottom wall to form an intermediate spun product and then a third V-shaped groove is spun in second state dies in the cylindrical cup side wall between the open end of the cup and the two initially spun grooves; providing dies for the manufacture of such a multigroove pulley in which the cup-shaped blank is supported by a cylindrical side wall portion of the cup adjacent the open end of the cup in the first stage spinning dies while the two V-shaped pulley grooves initially are spun in the cylindrical cup side wall adjacent the cup bottom wall; providing new dies for the manufacture of a V-groove pulley having at least three grooves formed in a single cup-shaped sheet metal blank in which certain desirable prior known manufacturing procedures are used and others are modified to cooperatively enable at least three relatively deep and narrow V-shaped grooves to be formed immediately adjacent one another in the cylindrical side wall of a cup-shaped sheet metal blank, without subjecting the blank metal to fracture or to localized or non-uniform stress, such as to inhibit the production of a uniformly strong dynamically balanced pulley; and providing apparatus for making a V-groove pulley having at least three grooves from a single cup-shaped sheet metal blank which eliminate difficulties heretofore encountered, achieve the various objectives indicated in a practical, workable and easily controlled manner, and solve problems and satisfies needs which have long existed in the art of spinning V- groove pulleys.

These objectives and advantages are obtained by the new apparatus for V-groove pulley manufacture, the general nature of which may be stated as including, means for forming a cup-shaped sheet metal blank by usual press operations; then providing a hub having an axial bore for and securing the same to the cup-shaped metal blank; then spinning two pulley grooves in first stage spinning dies in the cylindrical side wall of the cup-shapedblank adjacent the cup bottom wall to form an intermediate spun blank; maintaining concentricity of the cup-shaped blank and the two V-grooves spun therein during spinning in the first stage dies by supporting the blank concentrically in the axial hub bore, and within the open end of the cup outward of the location of the two grooves being spun in the cylindrical cup side wall; and then spinning a third groove in second stage dies in the cylindrical side wall portion of the intermediate spun blank between the open end of the cup and the two grooves spun therein to form a final three-groove spun pulley product.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred spinnning apparatus of the invention illustrative of the best mode in which applicants have contemplated applying the principles are illustrated in the drawings, are set forth in the following description, and are particularly and distinctly pointed out and set forth in the appended claims.

FIG. 1 is a somewhat diagrammatic side elevation of a spinning machine which may be used to carry out certain spinning steps;

FIG. 2 is a somewhat diagrammatic sectional view of a cup-shaped sheet metal blank which has been formed by usual press operations, and with which hub means has been assembled to provide the cup-shaped sheet metal blank in which three V-shaped pulley grooves are to be formed.

FIG. 3 is a view similar to FIG. 2 illustrating a blank formed in the first stage dies, and showing an intermediate spun product in which two V-shaped grooves have been formed in the cup side wall adjacent the cup bottom wall;

FIG. 4 is a view similar to FIGS. 2 and 3 illustrating a product formed in second stage spinning dies, and showing a third groove spun in the intermediate spun product of FIG. 3, between the open end of the cup and the two grooves spun in the first stage spinning dies;

FIG. 5 is a fragmentary diagrammatic sectional view illustrating the first stage spinning dies and showing the headstock and tailstock die assemblies separated with the blank of FIG. 2 inserted therebetween ready to be loaded on the dies carried by the headstock and tailstock assemblies;

FIG. 6 is a view similar to FIG. 5 showing the blank of FIG. 2 loaded on the first stage spinning dies, with the parts in the position ready for the rough rolling of two side-by-side grooves in the cylindrical side wall of the cup adjacent the cup bottom wall;

FIG. 7 is a view similar to a fragmentary portion of FIGS. 5 and 6 showing the rough rolling rolls home at the conclusion of the rough rolling portion performed in the first stage spinning dies;

FIG. 8 is a view similar to FIG. 7 illustrating the finish forming rolls in home position of the first stage die at the conclusion of the first stage spinning operation;

FIG. 9 is a view looking in the direction of the arrows 9-9, FIG. 5, illustrating the segments of the headstock groove-forming die in closed position to permit loading the blank of FIG. 2 on the headstock and tailstock dies;

FIG. 10 is a fragmentary view of certain of the parts of FIG. 9 with the segments in the out or expanded position, as illustrated in FIG. 6;

FIG. 11 is a fragmentary view of certain of the parts shown in FIGS. 9 and 10 looking in the direction of the arrows 1l-1l, FIG. 10;

FIG. 12 is a sectional view of one of the segments of the first stage headstock dies;

FIG. 13 is an exploded perspective view, with parts broken away in section, illustrating the adapter and headstock die insert and segment used in the first stage spinning dies;

FIG. 14 is a view similar to FIG. 5 of the second stage spinning die headstock and tailstock assemblies retracted for introducing the intermediate spun blank of FIG. 3 between the headstock and tailstock assemblies for loading the same;

FIG. 15 is a view similar to FIG. 6 illustrating parts used in the second stage spinning dies with the intermediate blank loaded on the headstock and tailstock dies and the second stage roughing roll in position ready to rough spin the third groove.

FIG. 16 is a view similar to FIG. 7 illustrating the second stage roughing roll in home position after forming the rough rolled third groove in the intermediate'blank.

FIG. 17 is a view similar to FIG. 8 illustrating the finish rolls in home position and providing the final V- groove pulley shape for the finished three side-by-side similar V- grooves in the intermediate blank, thus providing the multi-groove pulley of FIG. 4;

FIG. 18 is a view similar to FIG. 9 illustrating the second stage headstock dies with the segments in closed position looking in the direction of the arrows 18-18, FIG. 14;

FIG. 19 is a view similar to FIG. 10 illustrating the second stage headstock die segments in out position; and

FIG. 20 is a perspective view of the headstock die segment used in the second stage spinning dies.

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

DESCRIPTION OF THE PREFERRED EMBODIMENT The new apparatus of the invention may be used, and the new triple groove spun sheet metal products manufactured in equipment incorporated in spinning apparatus of the general type shown in US. Pat. No. 2,892,431 modified to enable a new triple groove pulley product to be formed. Such apparatus is indicated somewhat diagrammatically in FIG. 1.

A typical spinning machine 1 having first stage dies used for a first stage spinning operation has motor means 2 to drive a first stage headstock spindle 3. A first stage tailstock spindle 4 is joumaled in the tailstock 5 in axial alignment with the headstock spindle 3. Either one or both of the headstock and tailstock spindles may be driven, but preferably and usually one the headstock spindle is rotatably driven by the motor means 2.

Furthermore, the headstock spindle 3 and tailstock spindle 4 are relatively movable axially so as to separate the first stage headstock and tailstock die

assemblies

6 and 7, respectively, as shown in FIG. 5, and to move them axially toward one another to intermediate positions shown in FIGS. 6 and 7, and to a final or home position shown in FIG. 8.

A second stage spinning machine (not shown) generally similar to first stage spinning machine 1 is used for a second stage spinning operation and may be equipped with second stage headstock and tailstock die assemblies generally indicated at 8 and 9, respectively, in FIG. 14 in the retracted or separated blank-receiving position, in FIGS. 15 and 16 in intermediate positions, and in FIG. 17 in the final home position wherein the final three-groove pulley is produced.

First Stage Spinning Apparatus The first stage headstock spindle and die assembly is best'shown in FIGS. 5 and 6. Headstock assembly 6 includes adapter members 10 and 11 bolted together by bolts 12 and mounted on headstock spindle 3. An outer die sleeve 13 is bolted at 14 to adapter 11. An adapter sleeve 15 is axially slidably mounted within a central opening 16 in adapter 11 and a stop head 17 and an insert 18 are bolted at 19 and 20 to form with the adapter sleeve 15 a spool-like sub-assembly.

This spool-like assembly 17-15-18 is axially slidably movable within and relative to adapter 1 l and outer die sleeve 13. That is, stop head 17 is slidable axially within the central cavity 21 of adapter 11; and insert 18 is slidable axially within the inner-surface of the outer die sleeve 13. The spool-like assembly 17-15-18 normally is spring-pressed by springs 22 to the position shown in FIG. 5 wherein stop head 17 engages the shoulder 23 at the right-hand end of adapter cavity 21, viewing FIG. 5. However, the spool-like assembly 17-15-18 may move under pressure to the left from the position of FIG. 5 against the pressure of springs 22 to the position shown in FIG. 8 wherein the insert 18 engages and is stopped by the adapter 11.

The insert 18 is best shown in FIGS. 9, 10, 11 and 13 and includes a flange portion 24 and a sleeve portion 25 having a series of radially-extending slots 26 formed therein. The slots 26 extend between the inner and outer

cylindrical surfaces

27 and 28 of the insert sleeve 25, and one rounded end of each slot 26 extends in the form of a groove 29 in the face 30 of insert flange 24. The other rounded end 31 of each slot 26 is spaced from the nose 32 of insert sleeve portion 25. As shown, the sleeve nose 32 may be formed with a removable headstock nose plate 33 for ease of maintenance, since, as explained below, the nose plate 33 is subject to wear.

A series of headstock segments, generally indicated at 34 (FIGS. 12 and 13), is mounted on and carried by the insert 18. Each segment 34 has a tongue 36 shaped in cross section complementary to the cross-sectional shape of the slots 26, and the upper end of tongue 36 terminates in a curved or arcuate flange-like portion 36. The segment flange 36 is formed at one end with an upwardly projecting die segment groove support portion 37. The die segment support portion 37 is trapezoidal in cross section as shown in FIG. 12. Preferably, a pair of rounded spring grooves 38 is formed in the flange portion 36 of segment 34. One rounded edge 39 of tongue extends upward and projects from the edge 40 of segment flange portion 36. The lower end of each tongue 35, opposite the flange portion 36, is beveled at 41 downward from the rounded edge 39 approximately to the center of the tongue (FIG. 12); and this end of the tongue 41 also is beveled at 42 from each tongue side surface 43 toward the free lower end 44 of the tongue.

A series of segments 34 (eight segments are shown) is assembled with their tongues 35 extending radially in the insert slots 26 as shown in FIG. 9, and a pair of springs 45 seated in the spring groves 38 press the segments 34 radially inward to the full circle retracted position shown, wherein the end bevels 42 on the tongues 35 engage similar beveled portions on adjacent tongues to stop inward travel of the tongues 35. In this manner, a central opening 46 extends through the insert 18 and segment 34 assembly when the segments 34 are in full circle position of FIG. 9. An extended or out position of segments 34 is shown in FIG. 10, later described.

The outer die sleeve 13 is formed with a flange 47 with which the bolts 14 are engaged in mounting the die sleeve 13 on headstock adapter 11. A blank retainer and wear ring 48 also is bolted at 49 to the die sleeve 13 (FIG. 5).

The outer sleeve 13 has a cylindrical blank die support portion 50 which performs a major function in the new procedure for forming triple groove pulleys. The insert 18 of the spool-like assembly 17-15-18 is slidable axially within the die sleeve support portion 50, as shown in FIGS. 5 and 6 for example. A circumferential notch 51 is formed in retainer ring 48 adjacent the outer cylindrical surface 52 of die support portion 50 to provide an annular recess in which the outer end of a cup-shaped blank may be received and held in a manner later described, as shown in FIG. 6. The end of outer die sleeve support portion 50 opposite flange 47 (to the right in FIG. 5) has a conical shape indicated at 53 adapted to cooperate, as later described, with the trapezoidal shape of the die segment groove support portions 37 of segments 34.

The segments 34 normally are held in the retracted full-circle position shown in FIGS. 5 and 9 by springs 45 but may be moved to an extended or out position, as shown in FIGS. 6 and 10 by a mandrel 54. The mandrel is shown in retracted position in FIG. 5 and in extended or advanced position in FIGS. 6 and 10. The nose 55 of mandrel 54 when moving from the retracted to advanced position, engages the beveled portions 41 of tongues 35 of segments 34 and pushes the segments radially outwardly in the slots 26 of insert 18. The mandrel nose 55 enters the central opening 46 described above when moving the segments 34 radially outward. The cylindrical surface of mandrel 54 slidably engages the free ends 44 of tongues 35 when the segments are in the extended position of FIGS. 6 and 10 and the flange portions 36 of segments 34 engage and are supported by the inner cylindrical surface of the cylindrical blank support portion 50 of die sleeve 13, as shown in FIG. 6.

Movement of the mandrel between retracted and advanced positions is accomplished by connecting the mandrel operating shaft 56 (FIG. 6) with a preferably hydraulic cylinder 57 (FIG. 1) whose operation is coordinated with other components of the equipment in accordance with the programming of the operation of the spinning machine. The mandrel operating shaft 56 extends from the mandrel 54 to cylinder 57 through hollow members of the headstock and headstock spindle 3.

The first stage spinning tailstock die assembly 7 is mounted on a tailstock adapter 58 (FIGS. 5 and 6) preferably by a threaded coupling 59. The die assembly 7 preferably comprises an outer flanged sleeve 60, a journal sleeve 61, an outer die sleeve 62 and a pressure and support pad ring 63. The various sleeves and rings -61-62-63 are assembled by

bolts

64, 65 and 66. The outer die sleeve 62 at its outer or free end has a conical work surface shape indicated at 67 which also cooperates, as later described, with the work surfaces of the trapezoidal shape of the die segment groove support portions 37 of hedstock die segments 34.

The first stage headstock and tailstock die

assemblies

6 and 7 are designed to cooperate with roughing and finish spinning roll assemblies illustrated somewhat diagrammatically in FIGS. 6, 7 and8. These spinning roll assemblies are mounted for operation and movement on the spinning machine 1 so that the roughing rolls generally indicated at 68, first perform a rough multigroove spinning operation illustrated in FIGS. 6 and 7, and then the finish spinning rolls generally indicated at 69, perform the finish rolling of two-V-grooves during the first multi-groove spinning operation.

The first stage roughing roll and finish

roll assemblies

68 and 69 generally are similar to the roughing and finish rolls of US. Pat. Nos. 2,869,223 and 2,892,431. Thus, the roughing roll assembly 68 includes a roll holder 70, spindle means 71, an axially stationary roughing roll 72, and an axially movable roughing roll 73 normally biased away from roll 72 by spring means 74, as shown in FIG. 6. The roll holder 70 is mounted at one side of the headstock and tailstock first stage die

assemblies

6 and 7, and is movable toward and away from the

die assemblies

6 and 7 while the axis of the spindle means 71 is maintained parallel with the axis of the first stage headstock and tailstock die

assemblies

6 and 7.

The finish spinning roll assembly 69 is shown in FIG. 8, and is provided with a roll holder 75, spindle means 76, an axially stationary finishing roll 77, and an axially movable finishing roll 78. The finishing rolls 77 and 78 are biased axially away from each other by spring 79.

First Stage Spinning Operation The manufacture of a triple V-groove pulley on the improved dies in accordance with the present invention, starts with forming a cup-shaped sheet metal blank, as indicated at 80 in FIG. 2, from sheet metal of the required composition and thickness by usual press forming and drawing operations. The formed blank 80 has a cup bottom wall 81 and a cup side wall 82. The cup-shaped blank 80 then is mounted on a suitable hub 83 in any usual manner, for example, as by welding. A reinforcing stamped sheet metal flanged ring 84 may be included in the blank-hub assembly for stiffening and reinforcing the cup-bottom wall 81. Ring 84 also may be welded to the hub 83 and cup-bottom wall 81.

The cup-shaped blank 80 during manufacture is provided with an exact and uniform side wall axial length from the bottom wall corner 85 to the free or open end 86 of the cup-shaped blank 80. The hub 83 has an internal bore 87 with which the pulley grooves to be provided in the finally-formed product must be axially concentric. To achieve this characteristic, the side wall 82 of the cup-shaped blank 80 when assembled on hub 83 is formed and assembled cylindrically concentric with the bore 87 of hub 83.

The cup-shaed blank 80 assembled with its hub 83 and reinforcing ring 84, comprises the starting blank for the first stage spinning operation. In order to carry out the first stage spinning operation, the first stage headstock and tailstock die

assemblies

6 and 7 must be axially separated sufficiently to permit the blank 80 to be inserted between the

die assemblies

6 and 7 to load the blank thereon and to be engaged by the die work surfaces. The separated headstock and tailstock die

assemblies

6 and 7 with the mandrel 54 retracted and the cup-shaped blank 80 ready to be loaded on the die assemblies are shown in FIG. 5.

The tailstock is actuated, after placing the blank 80 between the

die assemblies

6 and 7, to move the die assembly 7 to the left toward the headstock, as shown by the arrow 8 (FIG. 6), so that the tailstock outer die sleeve 62 and its die work surface 67, and the pressure and support pad ring 63 engage the cup bottom wall 81; and so that the journal 61 engages an end of hub 83, all as shown in FIG. 6.

Further movement of the tailstock die assembly 7 in the direction of the arrow 88 telescopes the cup side wall 82 over the cylindrical blank support portion 50 (with which it just fits) of outer die sleeve 13 of the headstock die assembly 6 to a location where the free end 86 of blank 80 engages the notch 51 in the blank retaining and wear ring 48, as shown in FIG. 6.

Meanwhile, mandrel 54 is advanced in the direction of the arrow 89 (FIG. 6) from retracted position first to engage and radially expand the die segments 34 to the position shown in FIG. 6, and then to enter the bore 87 of the pulley hub 83 thereby establishing a condition of concentricity between all headstock and tailstock die components and the cup-shaped blank.

At this time in the progress of the first stage spinning operation, the various parts are in the position shown in FIG. 6 with the blank clamped between the headstock and tailstock die

assemblies

6 and 7. The bottom wall of blank 80 adjacent the corner is engaged externally in an annular zone by the die work surface 67 at the conical end of the outer first stage tailstock die sleeve 62. Also, the bottom wall 81 of the cup is externally engaged opposite the location of the flanged reinforcing ring 84 at a smaller conical annular zone by the die work-contacting conical surface of pressure and support pad ring 63. Also, a considerable portion 91 (almost half) of the length of the cylindrical cup side wall 82, fits over, and is supported by, and is engaged with the outer cylindrical surface of the blank support portion 50 of outer die sleeve 13. Finally, the free end 86 of blank 80 is trapped in the notch 51 of blank retaining and wear ring 48.

Thus, the cylindrical side wall 82 is clamped under axial pressure between the first stage headstock and tailstock die

assemblies

6 and 7. At this time, the roughing roll assembly 68 for the first stage spinning operation is located at one side of the headstock and tailstock die

assemblies

6 and 7, with the roughing rolls 72 and 73 separated, as shown in FIG. 6. The

rolls

72 and 73 are located at positions on either side of the location of the trapezoidally-shaped die segment groove portions 37.

The first stage tailstock then moves further toward the headstock in the direction of the arrow 88 from the position of FIG. 6 to that of FIG. 7, and at the same time the roughing roll assembly 68 is moved radially toward the axis of the spinning machine, that is an axis passing centrally through the mandrel 54 indicated by the dot-dash line 92 in FIG. 7. During these spinning roll and tailstock movements, the unsupported metal in the side wall 82 of the blank 80 between the corner 85 and the supported blank side wall portion 91 is worked, spun, displaced, and reshaped by the rough spinning rolls 72 and 73 to the shape in cross section indicated at 93 in FIG. 7. This metal shape 93 may be referred to as the double-groove, rough-spun shape or formation.

The double-groove shape 93, thus, is located in an annular zone of the cup side wall 82 immediately adjacent the corner 85. The remainder 91 of the cup side wall supported on the outer die sleeve 13 extending from the double-groove shape 93 to the free end 86 of the blank 80, retains its supported cylindrical shape. This cylindrical cup side wall portion 91 comprises the portion of the cup blank 80 wherein the third groove is spun during the second stage spinning operation, to be described.

The position of the various parts at the conclusion of the rough-spinning portion of the first stage spinning operation is shown in FIG. 7, with the rough-spinning roll assembly 68 in the home position completing rough-spinning of the rough-spun double-groove shape 93. During this portion of the rough-spinning operation, that is during movement of the components from the position shown, in FIG. 5 through the position shown in FIG. 6 to the position shown in FIG. 7, the spool-like assembly 17-15-18 on which the trapezoidally-shaped die segment pulley groove support portions 37 are mounted, remains in the position shown in FIGS. 5, 6 and 7.

After the rough-spinning rolls 72-73 have formed the double-groove shape 93, the roughing roll assembly 68 is retracted by moving the axis thereof away from the spinning machine axis 92. During such movement, the first stage finish spinning roll assembly 69 is moved radially toward the axis 92 of the spinning machine; and at the same time, the tailstock die assembly 7 is moved further in the direction of the arrow 88, as shown in FIG. 8. During these movements, the end 94 of the pulley hub 83 engages the headstock nose plate 33 of the spool-like assembly 17-15-18 and moves this assembly also in the direction of the arrow 88, FIG. 8, against the pressure of the spring means 22 until the insert 18 engages and is stopped by headstock adapter 11 (FIG. 8).

During this further tailstock movement from the position of FIG. 7 to that of FIG. 8, the spinning rolls 77 and 78, while moving radially toward the rotating blank 80 held between the headstock and tailstock die

assemblies

6 and 7 further work, spin, displace and reshape the rough-spun double-groove formation 93 of FIG. 7 to the first stage finish-spun shape indicated at 95 in FIG. 8. The finish spinning rolls 77 and 78 have a contour that shapes the finish-spun double grooves 95 with the desired V-groove formations, as shown.

As the finish roll spinning portion of the first stage spinning operation is completed, with the finish rolls 77-78 in the home position shown in FIG. 8, the metal in the side wall of the blank 80 being spun to the double V-groove shape 95 is ironed and cold-worked on the inner and outer surfaces of the V-groove shape, between the related and cooperative work-contacting die surfaces 67 of outer tailstockdie sleeve 62, of the V-shaped

peripheries

96 and 97, respectively, of the finish spinning rolls 77 and 78, of the work-engaging die surfaces of the trapezoidally-shaped die segment groove support portions 37, and of the conical and cylindrical work-engaging die surfaces 53 and 52 of the outer die sleeve 13.

One matter of importance to note is that at the conclusion of the finish roll spinning portion of the first stage spinning operation in the first stage dies as shown in FIG. 8, the supported blank side wall portion 91 is ironed between the outer die sleeve cylindrical support surface 52 and the cylindrical portion 98 of finish spinning roll 77. This ironing, as well as the trapping of the free end 86 of the blank 80 by the notch 51 in blankretaining and wear ring 48, not only maintains the supported cylindrical portion 91 of the cup side wall concentric with the remainder of the blank, but irons the engaged portion of the cup side wall portion 91 to maintain uniform thickness thereof, despite the working of adjacent metal originating from the cup side wall in forming the double V-pulley grooves indicated at 99.

The intermediate-spun blank with the double V- pulley grooves 99 formed therein, is illustrated in FIG. 3, indicated generally at 100. The intermediate-spun blank 100 now becomes the starting blank for the second stage spinning operation in which a third V-groove is spun in the cylindrical portion 91 of blank 100.

Second Stage Spinning Apparatus The improved second stage headstock and tailstock die assemblies 8 and 9, illustrated in FIGS. 14 through 20, are mounted on a spinning machine, such as illustrated in FIG. 1, in place of the first stage headstock and tailstock die

assemblies

6 and 7. Although FIG. 1 is described above as generally illustrating the first stage spinning machine, it is also illustrative of a second stage spinning machine because of showing three V- groove forming rolls later described.

The second stage headstock spindle and die assembly is best shown in FIGS. 14 and 15. Headstock assembly 8 includes

adapter members

101 and 102 bolted together by bolts 103 and mounted on headstock spindle 104. An outer die sleeve 105 is bolted at 106 to adapter 102. An adapter sleeve 107 is axially slidably mounted within a central opening 108 in adapter 102 and a stop head 109 and an insert 110 are bolted at 111 and 112 to form with adapter sleeve 107 a spool-like subassembly 109-107-110.

The spool-like assembly 109-107-110 is axially slidably movable within and relative to adapter 102 and outer die sleeve 105. That is, stop head 109 is slidable axially within the central cavity 113 of adapter 102; and insert 110 is slidable axially within the inner surface of the outer die sleeve 105. The spool-like assembly 109-107-110 normally is spring-pressed by springs 114 to the position shown in FIG. 14 wherein stop head 109 engages the shoulder 115 at the right-hand end of the adapter cavity 113, viewing FIG. 14. However, the spool-like assembly 109-107-110 may move under pressure to the left from the position of FIG. 14 against the pressure of springs 114 to the position shown in FIG. 17 wherein ring 116 engages and is stopped by adapter 102. The spring pressure imparted by springs 114 preferably is imparted from adapter 102 to a ring 116 which in turn engages a face of insert 110.

Insert 110 is generally similar to insert 18, and the assembly thereof with segments, is shown in FIGS. 18 and 19. Insert 110 includes a flange portion 117 and a sleeve portion 118 formed with radial slots 119 which extend between the inner and

outer surfaces

120 and 121 of sleeve 118. An annular sleeve nose plate 122 and retainer ring 123 are bolted at 124 to the outer end of sleeve 118 of insert 110.

A series of headstock segments, generally indicated at 125, one of which is shown in FIG. 20, is mounted on and carried by insert 110. Each segment 125 has a tongue 126 shaped in cross section complementary to the cross-sectional shape of the slots 119, and the upper end of tongue 126 terminates in a curved or arcuate flange-like portion 127. Flange 127 is fomed at one end with an upwardly-projecting die segment groove support portion 128. This die segment support portion 128 is trapezoidal in cross section, as shown in FIG. 14.

Preferably, a pair of rounded spring grooves 129 is formed in the flange portion 127 of segment 125. One rounded edge 130 of tongue 126 extends upward and projects from the other edge of segment flange portion 127. The lower end of each tongue 126 opposite the flange portion 127, is beveled at 131 downward from the rounded edge 130 approximately to the center of the tongue (FIG. 20); and this end of the tongue also is beveled at 132 from each tongue side surface 133 toward the lower free end 134 of the tongue.

This series of segments 125 (eight segments are shown) is assembled with their tongues 126 extending radially into the insert slots 119, as shown in FIGS. 18 and 19; a pair of springs 135 seated in the spring grooves 129 press the segments 125 radially inward to the full-circle retracted position shown in FIGS. 14 and 18, wherein the end bevels 132 on the tongues 126 engage similar bevel portions on adjacent tongues to stop inward travel of the tongues 126. In this manner, a central opening 136 extends through the insert 110 and segment'125 assembly when the segments 125 are in full-circle position of FIG. 18. An extended or out position of segments 125 is shown in FIG. 19, later described.

The outer die sleeve 105 is formed with internal and

external shoulders

137 and 138. The internal shoulder 137 forms a recess 139 internally of sleeve 105 into which the die segments 125 may move to extended position, as shown in FIG. 15. Shoulder 138 forms a retention stop member for the control ring 140 slidably mounted on an surrounding portion of the die sleeve 105.

Control ring 140 normally is in the position shown in FIG. 14 but may slide yieldingly on die sleeve 105 to the left, viewing FIG. 14, against the pressure of spring 141 reacting between the ring 140 and a flange 101a on adapter 101. Ring 140 has a tapered roll-engaging surface 142, the purpose of which is later described. Die sleeve 105 has a conically-shaped work-engaging surface 143 at its free end and an annular notch 144 is formed at the corner between the conical surface 143 and the outer cylindrical surface 145 of the die sleeve 105. The work-engaging surface 143 cooperates, as later described, with the trapezoidal shape of the die segment groove support portions 128 of segments 125.

The segments 125 normally are held in the retracted full-circle position of FIGS. 14 and 18 by springs 135 but may be moved to an extended or out position, as shown in FIGS. 16 and 19 by a mandrel 146. The mandrel is shown in retracted position in FIG. 14 and in extended or advanced position in FIGS. and 19. The nose 147 of mandrel 146 when moving from the retracted to advanced position, engages the beveled portions 131 of tongues 126 of segments 125 and pushes the segments radially outwardly in the slots 119 of insert 110. The mandrel nose 147 enters the central opening 136 described above when moving the segments 125 radially outward. The cylindrical surface of mandrel 146 slidably engages the free ends 134 of tongues 126 when the segments are in the extended position of FIGS. 16 and 19, and the flange portions 127 of segments 125 engage and are supported by the inner cylindrical surface of the recess 139 of die sleeve 105, as shown in FIGS. 15, 16 and 17.

Movement of the mandrel 146 between retracted and advanced positions is accomplished by connecting the mandrel operating shaft 148 (FIG. 16) with a preferably hydraulic cylinder such as the cylinder indicated at 57, FIG. 1, ofa second stage spinning machine. The operation of the cylinder controlling movement of the mandrel 146 is coordinated with the operation of the other components used in carrying out the second stage spinning operation in accordance with the programming of such operation. Mandrel operating shaft 148 extends from the mandrel 146 to the operating cylinder such as cylinder 57 through hollow members of the headstock and headstock spindle 104.

The second stage spinning tailstock die assembly 9 is mounted on a tailstock adapter 149 (FIGS. 14 and 15) preferably by a threaded coupling 150. The die assembly 9 preferably comprises an outer flanged sleeve 151, a journal sleeve 152, an outer die sleeve 153, and a pressure and support pad ring 154. The various sleeves and rings 151-152-153-154 are assembled by bolts 155, I56 and 157. The outer die sleeve 153 at its outer or free end has a conical work-engaging surface shape 158 which also cooperates, as later described, wtih the work surfaces of the trapezoidal shape of the die segment groove support portion 128 of headstock die segment 125.

The second stage headstock and tailstock die assemblies 8 and 9 are designed to cooperate with roughing and finish spinning roll assemblies, illustrated somewhat diagrammatically in FIGS. 15, 16 and 17. These second stage spinning roll assemblies are mounted for operation and movement on the second stage spinning machine so that the roughing roll assembly generally indicated at 159, first performs a rough third groove spinning operation, illustrated in FIGS. 15 and 16; and then the finish spinning roll assembly, generally indicated at 160, performs the finish rolling of the third V- groove while the shape of the first stage spun two V- grooves is maintained during the second stage multigroove spinning operation. 7

The second stage roughing roll and finish

roll assemblies

159 and 160 generally are similar to the first stage roughing and finishing roll assemblies, except that only one roughing roll is used in the second stage rough rolling operation. Thus, the roughing roll assembly 159 including a roll holder or spindle 161 on which the axially stationary roughing roll 162 is mounted. The roll spindle 161 is mounted at one side of the headstock and tailstock die assembles 8 and 9, and is movable toward and away from the die asemblies 8 and 9 while its axis is maintained parallel to the axis of the second stage headstock and tailstock die assemblies 8 and 9.

The finish spinning roll assembly 160 is shown in FIG. 17 and is provided with a roll holder and spindle means 163, an axially-stationary finishing roll 164 and two axially-movable spinning rolls 165 and 166. The finishing rolls 165 and 166 are biased away from roll 164 by spring means 167.

Second Stage Spinning Operation The intermediate spun blank with double V- pulley grooves 99 formed therein comprises the starting blank for the second stage spinning operation. In order to carry out the second stage spinning operation, the second stage headstock and tailstock die assemblies 8 and 9 must be axially separated sufficiently to permit the blank 100 to be inserted between the die assemblies 8 and 9 to load the blank thereon and to be engaged by die work surfaces. The second stage headstock and tailstock die assemblies 8 and 9, separated, with the mandrel 146 retracted and the intermediate spinning blank 100 ready to be loaded on the die assemblies are shown in FIG. 14.

The tailstock is actuated, after placing the blank 100 between the die assemblies 8 and 9, to move the die assembly 9 to the left toward the headstock, as shown by the arrow 168 (FIGS. 14 and 15), so that the tailstock outer die sleeve 153 and its die work surface 158, and the pressure and support pad ring 154 engage the bottom wall 81 of the intermediate blank 100; and so that the journal sleeve 152 engages an end of hub 83, all as shown in FIG. 15.

Further movement of the tailstock die assembly 9 in the direction of the arrow 168 telescopes the portion 91 of the cup side wall around, and over the insert and die segment assembly of members and 125, until the free end 86 of the intermediate blank 100 engages the notch 144 in the outer die sleeve 105 beneath an end portion 169 of control ring 140, as shown in FIG. 15. The free end 86 of intermediate blank 100, thus, is trapped in notch 144 inside .of the control ring end portion 169.

Meanwhile, the mandrel 146 is advanced in the direction of the arrow 170 from the retracted position of FIG. 14 to the position shown in FIG. 15. During such movement, the nose 147 of the mandrel, and the mandrel itself, radially expand the die segments 125 to the position shown in FIG. 15, and then the mandrel enters the bore 87 of the pulley 83 thereby establishing a condition of concentricity between all headstock and tailstock die components and the blank 100.

At this time in the progress of the second stage spinning operation, the various parts are in the position shown in FIG. 15 with the blank 100 clamped betwen the headstock and tailstock die assemblies 8 and 9. The bottom wall 81 of the blank 100 adjacent the two V- groove formation 99 is engaged externally in an annular zone by the die work surface 158 at the conical end of the outer second stage tailstock die sleeve 153. Also, the bottom wall 81 of the blank 100 is externally engaged opposite the location of the reinforcing ring 84 at a smaller conical annular zone by the conical die work-contacting surface 171 of pressure and support pad ring 154.

Thus, the cylindrical side wall portion 91 of the blank 100 is clamped under axial pressure between the second stage headstock and tailstock die assemblies 8 and 9 (FIG. 15). At this time, the roughing roll assembly 159 for the second stage spinning operation is located at one side of the headstock and tailstock die assemblies 8 and 9, with the roughing roll 162 location, as shown in FIG. 15, at a position intermediate the ends of blank cylindrical side wall portion 91 and opposite the space between the outer die sleeve work-engaging surface 143 and the segment die support portions 128.

The second stage tailstock then moves further toward the headstock in the direction of the arrow 168 from the position of FIG. 15 to that of FIG. 16; and at the same time, the roughing roll assembly 159 is moved radially toward the axis of the spinning machine, that is an axis passing centrally through the mandrel 146 indicated by the dot-dash line 172 in FIG. 16. During these spinning roll and tailstock movements, the metal in the cylindrical side wall portion 91 of the intermediate blank 100 between the free end 86 is trapped in notch 144 and the double-groove formation 99 is worked, spun, displaced and reshaped by the rough spinning roll 162 to the shape in cross-section, indicated at 173 in FIG. 16. This metal shape 173 may be referred to as the third-groove roughspun shape or. formation.

The third groove shape 173, thus, is located in the annular zone of the cup side wall between the double V- groove shape 99 and the 'traped free end 86 of the blank 100.

The position of the various parts at the conclusion of the rough-spinning portion of the second stage spinning operation is shown in FIG. 16, with the rough-spinning roll assembly 159 in the home position completing the rough-spinning of the third groove to the roughspun third-groove shape 173. During this portion of the second stage rough-spinning operation, that is during movement of the components from the position shown in FIG. 14 through the position shown in FIG. 15 to the position shown in FIG. 16, the spool-like assembly 109-107-110 on which the trapezoidally-shaped die segment pulley groove support portions 128 are mounted, remains in the position shown in FIGS. 14, 15 and 16.

After the rough-spinning roll 162 has formed the third groove shape 173, the roughing roll assembly 159 is retracted by moving the axis thereof away from the spinning machine axis 172. During such movement, the second stage finish spinning roll assembly 160 is moved radially toward the axis 172 of the spinning machine; and at the same time, the tailstock die assembly 9 is moved further in the direction of the arrow 168, as shown in FIG. 17. During these movements, the end 94 of the pulley hub 83 engages the headstock nose plate 122 of the spool-like assembly 109-107-110 and moves this assembly also in the direction of the arrow 168, against the pressure of spring means 114 until the insert 110 and its ring 116 engage and are stopped by headstock adapter 102 (FIG. 16).

During this further tailstock movement from the position of FIG. 16 to that of FIG. 17, the finish spinning roll 164 while moving radially toward the rotating blank 100 held between the headstock and tailstock die assembliles 8 and 9 further works, spins, displaces and reshapes the rough-spun third groove shape 173 of FIG. 16 to the second stage final spun shape of FIG. 17. During this finish spinning of the third groove by the finish spinning roll 164, the finish spinning rolls 165 and 166 engage in and support the V-groove contours of the two-groove formation 99 of the intermediate blank 100 to form a finished spun triple V-groove contour 174 for the completed triple-groove pulley, indicated at 175 in FIGS. 4 and 17.

As the finish roll spinning portion of the second stage spinning operation is completed, with the finish rolls 164-165-166 in the home position, shown in FIG. 17, the metal in the walls of the various grooves of the three-groove formation 174 being spun is ironed and cold-worked on inner and outer surfaces of the triplegroove shape, between related and cooperative workcontacting die surfaces 158 of the outer tailstock die sleeve 153, of the V-shaped peripheries of the finish spinning rolls 164, 165 and 166, of the work-engaging die surfaces of the trapezoidally-shaped die segment groove support portions 128, and of the conical workengaging die surface 143 of the outer die sleeve 105.

As the finish spinning roll assembly 160 moves to final home position of FIG. 17, a conical surface 176 on spinning roll 164 engages the roll-engaging surface 142 of control ring 140, moving the control ring 140 to the left from the position of FIG. 16 so that of FIG. 17 against the pressure of spring means 141 to expose a trapped cylindrical end portion 177 of the blank 100 so that the portion 177 as well as the remainder of the triple-groove V-groove formation 174 is ironed between the cooperating and work-engaging die and spinning roll surfaces to provide and maintain the concentric formation of all portions of the finished triple-groove pulley 175. This ironing also provides or maintains uniform thickness of the walls of the triple-groove shape thereby imparting dynamic balance to the finished triple-groove pulley 175.

In

General Nose plates

33 and 122 forming part of the first and second stage headstock die assemblies have been indicated as aiding in the ease of maintenance. The nose plates are readily accessible for change by removing the bolts which assemble them to the inserts on which they are mounted. These nose plates, as described, Finally engage under pressure the hubs and related portions of pulley blanks being spun. Under these conditions, the hubs and the flanged reinforcing rings on the pulleys during loading and spinning may rub the nose plates so as to produce wear on the engaged surfaces thereof. The maintenance of pressure between headstock and tailstock dies and the blanks being worked, as well as the maintenance of concentricity, etc., require close tolerances to be maintained at all times, and thus, removability of the nose plates is of importance for replacing worn nose plates.

The

segments

34 and 125 of the first and second stage headstock die assemblies have been described in both the full-circle and out positions. These positions are of importance to permit the work-contacting die surfaces of the segments to engage and support blank metal being cold-worked to form the V-shape when the segments are in the out position, as well as to permit the segments to be retracted to the position of FIGS. 5 and 14 so that the intermediate pulley blank 100, or the final triple-groove pulley 175 may be removed from the headstock dies.

As previously indicated, the work-engaging

surfaces

37 and 128 of the trapezoidally-shaped die support portions of the

segments

34 and 125 cooperate with the work surfaces 53, 67, 143 and 158 of the headstock and tailstockouter die sleeves of the first and second stage headstock and tailstock die assemblies to work annular metal portions of the pulley blanks in forming the triple V-grooves in the cylindrical side wall of the pulley blanks.

Both the first stage and

second stage blanks

80 and 100 have been described as having the free ends thereof trapped and held in position during the first and second stage spinning operations This is of importance to enable the blanks to be maintained under axial pressure during the progress of the spinning operations and to maintain concentricity of the cylindrical blank side wall with the remaining portions of the blank at all times. Furthermore, during the first stage spinning operation, the trapping of the free end of the blank in the notch 51 enables the portion 91 of the first stage blank 80 to be held and supported cylindrically on the headstock die assembly while the severe working of the metal between the cylindrical blank portion 91 and the corner 85 occurs during the formation of the double groove in the blank. Meanwhile, the metal in the cylindrical portion 91 of the intermediate blank 100 has remained unworked so as to permit the third pulley groove to be formed therein by the same type of spinning operation that has severely cold-worked other portions of the blank to form the first two grooves.

The control ring 140 enables the free end of the blank to be trapped during the second stage spinning operation and its surface 142 to be engaged by the finish spinning roll 164 to displace the control ring and finally iron the trapped portion 177 of the blank at the conclusion of a finish spinning operation.

The various cooperative relationships between the improved dies of the present invention described, enable the blank metal to be supported and maintained concentric at all times during the progress of the extremely severe cold-working of the metal accompanying the formation of a triple-grooved pulley in a onepiece metal blank.

The cup-shaped blank formed of a single piece of sheet metal with a cylindrical side wall 82 integral with its bottom wall 81, has been described as having an exact and uniform side wall axial length from the bottom wall corner to the free end 86. This exact length may be achieved by trimming a cup-shaped blank drawn or otherwise formed in a usual manner on a trimming machine, such as shown in US. Pat. No. 2,702,597.

The spinning machine indicated diagrammatically at 1 has been described as a typical spinning machine of the general type shown in US. Pat. No. 2,892,431, wherein mounting, movement, and control of rough and finish spinning roll assemblies is illustrated. This mounting is generally indicated at 178 in FIG. 1. Such a typical spinning machine on which the headstock and tailstock die assemblies and the rough and finish spinning rolls may be mounted and actuated, also is shown in US. Pat. No. 2,062,415. In such typical spinning apparatus, the headstock and tailstock spindles both may be driven at the same speed of rotation, and the related coordinated movements of the various die and roll assemblies, mandrels, etc., may be effected either by mechanical or hydraulic means.

The final ironing of the metal surfaces of the initiallyformed double-groove 99 at the end of the first stage spinning operation, and the final ironing of the triplegroove formation 174 at the conclusion of the second stage spinning operation, just as the respective finish spinning rolls during each stage reach their limits of inward movement, uniformly work, size and shape the V-groove formations and the thickness of the metal walls. In this manner, a finished triple groove pulley has static and dynamic balance and true concentricity and has dense, smooth, work-hardened and truly-formed roller-spun triple V-grooved surfaces.

Fundamental facets of the new concept involved the procedure and equipment for the two-stage spinning operations, and the manufacture of a triple-groove pulley starting with the formation of a cup; followed by a first stage spinning of two V-grooves in the lower portion of the cup side wall adjacent the bottom wall of the cup; using an extended cylindrical cup side wall portion at the open end of the cup wherein a third groove is formed during the second stage spinning operation and beyond the two grooves that are formed, as a means of supporting the cup on a long cylindrical headstock die portion during the first stage spinning operations; and then spinning a third groove in said cylindrical side wall portion of an intermediately-formed product, between the two grooves and the open end of the cup.

Accordingly, the present invention provides substantial improvements in the art of making roller-spun V- groove pulleys; provides for the manufacture of a statically and dynamically-balanced concentric triplegroove pulley in a one-piece metal blank; satisfies the various objects set forth; solves problems and satisfies demands existing in the art; and obtains the new results indicated.

In the foregoing description, certain terms have been used for brevity, clearness and understanding; but not unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described or to be exact pulley shape, dies, rolls and pulleys shown, since they may be varied to provide other structural embodiments.

For example, the cup-shaped blank 80 is shown and described as having a suitable hub 83 mounted thereon. Some pulleys will not necessarily have a hub of this character. The bottom wall 81 may only be provided with a central opening, which opening is used the same as the hub bore 87 to center the cup-shaped blank bottom wall on a mandrel when clamped between headstock and tailstock dies.

Having now described the features, discoveries and principles of the invention, the manner in which the new triple-groove pulley may be manufactured, the construction and operation of improved roller spinning dies, the details of the steps of improved method, and the advantageous, new and useful results obtained; the new and useful inventions, constructions, devices, parts, elements, arrangements, combinations, subcombinations, discoveries, principles and products are set forth in the appended claims.

We claim:

1. ln apparatus for forming multi V-groove sheet metal pulleys of a type in which the cylindrical side wall of a cup-shaped sheet metal blank is clamped axially between rotatable and relatively axially movable headstock and tailstock die assemblies and subjected to axial pressure while V-shaped grooves are being rollerspun in portions of said cup cylindrical side wall, and in which inner portions of the cup side wall are engaged and supported during roller spinning by groove support die segments radially movable between the headstock and tailstock die assemblies and axially movable relative to the headstock and tailstock die assemblies; the improvement including a cylindrical headstock outer die sleeve having an inner cylindrical surface; a cylindrical insert mounted and axially slidable within the headstock die assembly located within the outer die sleeve, the insert having a sleeve projecting toward the tailstock spaced from and concentric with the outer die sleeve inner cylindrical surface and formed with a series of radially-extending slots elongated axially in cross-section; a series of segments carried by said insert, each segment having a tongue radially-movable in one of the insert slots, an arcuate flange at the outer end of each tongue projecting toward the tailstock and located between the insert sleeve and outer die sleeve, and a radially-projecting groove support die segment portion on said flange trapezoidal in cross section; mandrel means axially movable within the headstock die assembly engageable with the segment tongues to move the segments radially outward of the insert sleeve; and the segment flange engaging and being supported by the inner cylindrical surface of the outer die sleeve when moved radially outward by the mandrel.

2. The apparatus set forth in claim 1 in which each arcuate segment flange is formed with arcuatelyextending groove means; and in which spring means engage the flange groove means of the series of segments normally urging the segment tongues radially inward of the insert sleeve.

3. The apparatus set forth in claim 1 in which the segment tongues are shaped in cross section complementary to the cross-sectional shape of the insert slots and have rounded front and rear edges and flat side surfaces; and in which each of the tongues rounded rear edges projects axially from an end of the segment arcuate flange opposite the radially-projecting groove support die segment portion.

4. The apparatus set forth in claim 3 in which the lower end of each segment tongue is beveled downward from the rounded rear edge approximately to the center of the tongue; and in which the lower ends of tongue side surfaces are beveled downwardly inwardly.

5. The apparatus set forth in claim 3 in which the arcuate flange extends axially beyond the rounded front edge of each tongue.

6. The apparatus set forth in claim 1 in which the sheet metal blank is of a type having an open end; in which the headstock and outer die sleeve includes cup blank retaining means and a cylindrical blank die support portion; in which said support portion has an outer cylindrical surface which extends from said retaining means toward the tail stock; in which the retaining means is ring-shaped and surrounds and projects outwardly from the support portion outer cylindrical surface, and is formed with a circumferential notch adjacent said support surface; and in which said notch forms an annular recess with the support surface for receiving and holding the open end of a cup-shaped blank, with said support surface engaging and supporting the metal blank side wall during formation of the V-shaped grooves to maintain concentricity of the cylindrical blank side wall.

7. The apparatus set forth in claim 6 in which an end of the support portion opposite the retaining means has a conical shape; and in which said conical-shaped support portion end cooperates with the trapezoidal shape of the die segment groove support portions to form the V-shaped grooves in a metal blank.

8. The apparatus set forth in claim 1 in which the cylindrical insert sleeve has an outer end; and in which nose plate means is removably mounted on said sleeve outer end.

9. The apparatus set forth in claim 8 in which bolt means removably mount the nose plate means on the insert sleeve outer end.

10. The apparatus defined in claim 1 in which the tailstock die assembly includes a die sleeve having an outer free end with a conical work surface formed on said outer free end; and in which said conical work surface cooperates with the trapezoidal shape of the headstock die segment groove support portion to form the V-shaped grooves in a metal blank.

11. The apparatus defined in claim 10 in which the tailstock die assembly includes a pressure-support pad ring which is concentric to and located within the tailstock die sleeve conical work surface; in which said pad ring has a conical work surface spaced from the tailstock die sleeve outer conical work surface; in which the pad ring work surface slopes inwardly toward the center of the ring and in which said tailstock die sleeve work surface slopes outwardly from the center of said die sleeve; and in which said conical work surfaces are adapted to engage a bottom wall of the cup-shaped blank to form a generally V-shaped depression therein.

Claims

1. In apparatus for forming multi V-groove sheet metal pulleys of a type in which the cylindrical side wall of a cup-shaped sheet metal blank is clamped axially between rotatable and relatively axially movable headstock and tailstock die assemblies and subjected to axial pressure while V-shaped grooves are being roller-spun in portions of said cup cylindrical side wall, and in which inner portions of the cup side wall are engaged and supported during roller spinning by groove support die segments radially movable between the headstock and tailstock die assemblies and axially movable relative to the headstock and tailstock die assemblies; the improvement including a cylindrical headstock outer die sleeve having an inner cylindrical surface; a cylindrical insert mounted and axially slidable within the headstock die assembly located within the outer die sleeve, the insert having a sleeve projecting toward the tailstock spaced from and concentric with the outer die sleeve inner cylindrical surface and formed with a series of radially-extending slots elongated axially in cross-section; a series of segments carried by said insert, each segment having a tongue radially-movable in one of the insert slots, an arcuate flange at the outer end of each tongue projecting toward the tailstock and located between the insert sleeve and outer die sleeve, and a radially-projecting groove support die segment portion on said flange trapezoidal in cross section; mandrel means axially movable within the headstock die assembly engageable with the segment tongues to move the segments radially outward of the insert sleeve; and the segment flange engaging and being supported by the inner cylindrical surface of the outer die sleeve when moved radially outward by the mandrel.

2. The apparatus set forth in claim 1 in which each arcuate segment flange is formed with arcuately-extending groove means; and in which spring means engage the flange groove means of the series of segments normally urging the segment tongues radially inward of the iNsert sleeve.