US2616410A

US2616410A - Universal wire die machine

Info

Publication number: US2616410A
Application number: US125786A
Authority: US
Inventors: Frank M Potter; Robert M Hartman
Original assignee: General Cable Corp
Current assignee: General Cable Corp
Priority date: 1949-11-05
Filing date: 1949-11-05
Publication date: 1952-11-04
Anticipated expiration: 1969-11-04

Description

Nov. 4, 1952' F. M. POTTER ETAL UNIVERSAL WIRE DIE MACHINE 4 Sheets-Sheet l Filed Nov. 5, 1949 www m ATTORNEYS Nov. 4, 1952 F. M. POTTER ErAL 2,616,410

UNIVERSAL WIRE DIE MACHINE Filed Nov. 5, 1949 4 Sheets-Sheet v2 v ATTORNEYS w s Y mem @m 6 e NUR R 1 mm 0 EOM o 6, .y y MMM n 2 n 9 A xr A m a Nm u M g www W Wm E J.. ...m A A MO A HM 7? w E 7 h 7 RT. ED TE 1.. T .om mw .e L 6 m M. A W. FV I w Nov. 4, 1952 Flled Nov 5. 1949 Nov. 4, 1952 F. M. POTTER ETAL UNIVERSAL WIRE DIE MACHINE 4 Sheets-Sheet 4 Filed Nov. 5. 1949 ATTORNEYS 'atentec ov. 4, 1952 Ten STAT Es o F Fice- UNIVERSAL WIRE DIE MACHINE' FrankY M. Potter andRobert M. Hartman, Rome,

N. Y., assignors to General Cable Corporation,V

New York, N. Y., a' corporation of New' Jersey Application November.` 5, 1949i; Serial No; 125,786.

16' Claims. Cl. 125-43'07 Y This.: invention relates. to machines for the manufacture ofwire drawing-dies, and more par.- ticularly toa universal machine which may be usedto ,countersinl drill,v shape, recut, and polishY aliardde. material Ato a. nished wire drawing die. "I'liese-operations are performedby a..lap.

pingproeess in wliicllanabrasive material, comlmonly. diamondpo'Wder suspended'n l.oil or other lidi'c'lfis. applied'. to.' a. rapidly rotating. needle.- like dilllu'sually steel.l

or other liard'material's. Asused herein, .the term drillihg "is not restricted to thev step. of piercing the diamond, but is used" generically to include the various. cutting and polishing steps in the manufacture' of ajw're. drawing' die" which are performedby' the lapping` process'.

ltv s'an'O'bjectlof'theinvention to provide im-y prayedl` apparatus' for" the' manufacture of wire' drawing'dies It" also'v is an object of 'the inventinn'to. provide' `univ'ei'f'sa'l apparatus' which mayne'nseutc'perform emciently'all of the' steps' involved'l in' piercing' 'and iinishing a' wire draw# ing die.' It' is'a' frther object of the invention to provide a multiple unit apparatus' in which a plurality 'of wire drawing dies in various. stages ofthe" manufacturing process canbe simultaneouslyworked' on', each vwith maximum eineiency,v a relatively inexperienced operator.

Other` oject's. andiadvantages of the invention winappearhereinafitr. l Y

A?. preferred? embodiment AofV the invention'y has beemselected. for purposesof; illustration and description.. andi is shown*V in the accompanying' drawings wherein:

Figure '1" is a top plan View of `asixteen spindle machine, three ofthedrilling .unitsA being. substantially fully shownand. the. other thirteen beingpartiallyjshown 'FigureZ'is aside-'elevation ofthe machine with only one of 'thedrilling unitsbeing shown, and' with part" of the apparatus broken awayin vertical section to. disclose the construction more clearlyf Figure 3L i's .ai front `elevation ofthe machine. looking'toward' the leftslde of' Figure 2, only The supportcar'ying, the'di or'die' material and the rotating holder one of the drillingv units being shown,.andlpar1fv of theconstructionbeing broken away' in vertical section;-

Figure 4 is Vafhorizontal section' through' the machine substantially on line 4--4 of- Figure 2, disclosing the Vbelt drives for rotatingv ther die supports;

"Ffifgine ayertical section through vthe plate.Y or` work-supporting spi-nd-le and cam,` subfstantially Online 5--5 of Figure 3; and.

Figure 6 is a vertical section through.the-rollerv dies, the cutting member commonly comprises1-asharpened steel needle secured to` the-lower end off a spindle rotating at speeds which usually liel inlthe. range of about2500 toi4500 R. P..M. 'lhediamond, which may be encased in metal except for.4 relatively small exposedareas atv the. endsjof. the die opening whiehis tobe drilled, .is-.mounted- Ona holder which has a short reciprocatorynio-'-l tion alongthe axis of the spindle supporting the drilling needle, and which also may be rotated,4 at

relativelyl lower speed, in the opposite direction to the needle. Diamond powder of suitable grade' though there lmay be a wide variationin the sizel of "the holesl being drilled and in the stage of prgress of the drilling, shaping or nishingop-Y erations for the several die blanks being processed: in the machine at any onetime. Control ofthe drilling operation for any particulary die blanky in suchmachines is possibleonly through' thefshapez of the drilling needle, and through the grade' or size of diamond powder or other abrasiveused.

. Much depends on the experience and judgment of thev machine operator to produce an acceptable. finished die, and serious limitations are imposed".

evenY on the experienced operator.

Accordingv to the present invention', improved:

apparatus is provided for the manufacture of wire drawing dies in which the' operator of al multiple spindle machine may individually adjust bythat. particular needle on itsA particular die Moreover', the speed and extent of reciprocation 3 of the die holder relative to the needle spindle may be selected individually, and the pressure of the needle on the diamond, and the time of contact therebetween, may be individually adjusted for most eiiicient performance.

Less skill and experience is required of the operator to' produce satisfactory dies, and it is possible to produce dies of more uniformly high quality in less time and at lower cost. Moreover, by reason of its construction, the machine of the present invention permits a single operator to handle simultaneously and efliciently a larger number of spindles than is possible Vwith Wire die machines heretofore known, and with less fatigue and strain.

Referring now more particularly to the drawings, wherein like reference characters denote similar parts, and first to Figures 2 and 3, the machine of the illustrative embodiment comprises a stationary turntable base I I, which is mounted on the top I2 of a table or similar support. The turntable base comprises a circular ring, which may be made of cast iron. The lower edge of this ring has an outwardly ilared flange I4 which rests on the table top I2 and is secured thereto `by screws or bolts I3.

' Spanning the interior of the ring II, and secured thereto by screws, is a bar, spider or plate I6, preferably made of steel, which serves to support the main drive shaft I1, as will appear more particularly hereinafter. The upper edge of the ring I is provided with a circular raceway I5.

Mounted on the turntable base II, and free to rotate about its longitudinal axis, is a vertically disposed cylindrical housing consisting of aligned lower and upper cylindrical members I8 and I9, respectively, which conveniently are made of cast iron. As far as theoperation of the machine is concerned, the members I8 and I3 may be made as one, but for convenience in manufacture, the cylindrical housing preferably is made in two parts which are joined together by screws or bolts 20 passing through interior fianges or matching lugs, as shown.

The lower edge 2B of the cylindrical member I8 is machined to nt the circular raceway I and is free to turn therein, thus permitting the cylindrical housing IB-I 9 to be rotated about its longitudinal axis on the turntable base. Suitable bearing surfaces will be provided, or ball or roller bearings may be employed, if desired, to insure ease of rotation.

Means may be provided for selectively holding the cylindrical housing I8--I9 against rotation, relative to the turntable base I I, in a plurality of different positions. As shown, the lower edge 26 of the cylindrical member I8 is provided around its periphery with a plurality of equally spaced holes 34, which are adapted to be engaged by the inner end of the plunger 35. Surrounding the plunger, between collar 3l and guide 36, is a compression coil spring 38, which normally presses the plunger inwardly. The outer end of the plunger 35 may be provided with a knob 39 or the Y like for the convenience of the machine operator.

Withdrawing the inner end of the plunger from the hole 34 in which it happens to be engaged permits the cylindrical member I-IS to be turned in either direction about its longitudinal axis, until the plunger is released to engage another one of the holes 34. The number and positioning ofthe holes 34 in the edge 26 is such that the cylindrical member I8-I 9 can be held against rotation with any one of the drilling spindle units, to be described, directly in front of the operator.

The lower cylindrical member I3 is provided with a plurality of circumferentially spaced openings 2| around its periphery to permit the passage of belts which serve to drive the work-supporting spindles from the main drive shaft I 1, in the manner which will be described hereinafter.

The upper part of the cylindrical housing I8-I9 is formed so that there can easily be mounted thereon, or secured thereto, spaced circumferentially therearound, a plurality of drilling spindle units, each unit comprising a drill-carrying spindle and an aligned work-supporting spindle. In the illustrative embodiment, the drillcarrying spindle and the work-supporting spindle of each unit are mounted in a bracket 22, which is secured to the outer surface of the cylindrical member I9, but it will be understood that considerable variation in the mounting of the spindles on the cylindrical member IB--IB is possible within the scope of the subjoined claims.

In the illustrative embodiment there are sixteen of these drilling spindle units, but it will be understood that the number may vary. Preferably the number of drilling spindle units will be such that the operator of the completed machine will just be nicely able to take care of all ofthe drilling spindles in the normal course of wire drawing die manufacturing operations.

As shown, the lower and upper ends of the'cylin'- drical member I9 are formed with thickened rims, each of which is provided exteriorly with a plurality of fiat surfaces which give to the rima polygonal contour. `The flat surfaces 23 on thev lower rim are aligned Awith the flat surfaces 24 on the upper rim, so that the drilling spindle brackets 22 of the illustrative embodiment can be readily secured to the cylindrical member I9, as will appear hereinafter. v

vExtending across the top of the cylindrical member I9 and securedthereto, as by screws, is a cross arm 25, which, as will be explained, supports a bearing for the upper end of the main drive shaft I'I. This cross arm may be made of cast iron. s y

The arrangement of the sixteen drilling spindle units 22 around the periphery of the cylindrical member I9 can be seen in Figure l, which is a top plan view of the machine. In this View, lthree of the drilling spindle brackets with their associated equipment are fully shown. It will be understood that the other thirteen drilling spindle brackets will be similar in all important respects and that they are incompletely shown here merely to simplify the drawings.

In Figures 2 and 3, a single drilling spindle bracket is shown secured on the cylindrical member I9, but again this is merely for the purpose of simplifying and clarifying the drawings, and it will be understood that the completed machine will have sixteen of the drilling spindle brackets uniformly spaced around the cylindrical member I9. The construction of the drilling spindle brackets of theA illustrative embodiment, and their method of attachment to the cylindrical member I 9, may be understood by reference to Figures 1,12 and 3. l

The drilling spindle brackets 22 ordinarily will be made from cast iron. The brackets may all be alike, although only part of them need have spindles projecting downwardly therefrom for mounting idler sheaves, as will appear more fully hereinafter.

The vertical or back plate 28 of the bracket 22 is, rectangular in shape, substantially coextensive in length withv the cylindrical member 19;.and of awidth equal to or slightly-less than the horizontal dimension of the fiat-

surfaces

23, 24. Holes are-drilled throughthe back' plate: 28

near.A its upper and lower ends to receive screwsl 21.which engageA tapped holes in the flat surfaces 23 and 2,4. These screws 21 secure the bracket.

the=upper portion of the back plate 28fis the. solev 30, in the outer end of which is' mounted the drill-carrying spindle 33, which is aligned with the'workr-supporting spindle 32. The

soles

29 and 30 desirably are reinforced by a web such as is shown at 3|, extending outwardly from the back plate 28.. i i

-The

solesv

29 and 30 are of substantially similar shape and dimensions. As can be seen from Figures 1 and 3,- the center lines of these soles donot extend radially from the cylindrical member I9, but instead are curved so that the aligned

spindles

32 and 33 are displaced to oneside, to the left as viewed in Figure 2, of a verticalplane passing.` through the longitudinal axis of the cylindrical member I9 and also through the. vertical center. line of the.` back plate 28. As will appear more fully hereinafter, this displacement facilitates connecting the drill-carrying spindle to the variable speed transmission byl a means of aflexible shaft, without enlarging the machine toa point which would make it impractical.

A. method of mounting the work-supporting spindle 32 in the outer end of the sole 29 is shown in'detailA in Figure 5. lThe thickened end of the sole has a vertical bore to receive the flanged sleeve 4|. This sleeve may besecured in the bore of the solein known conventional manner, for

example byl means of screws which extendr down-- wardly. through drilled openings in the flange and engage tapped holes in the sole,vas shown..

Rotatably and slidably mounted within .the sleeve 4l, with ball or other suitable bearings, is the spindle 32. y

Secured on the upper end of the spindle 32 is the die plate or work support 42. A plurality of concentric grooves may be cut in the upper surfacev of the work support, as shown, or it may be otherwise treated to facilitate sticking a diamond die thereon in known manner. Surroundingthe spindle 32 and located between its upperbearing and the work support 42 is a compression coil spring 43, which normally presses the work support and attached spindle upwardly. Preferablyv the coil spring 43 is enclosed, for example by providing the upper end of the sleeve 4I and the lower edge of. the work support 42 with telescoping sleeves, as shown. y

Secured on the lower end ofthe spindle 32, as by means of a set screw, is the cam-faced sheave 45. The upper surface of the sheave rim,which is the'cam face, engages the lower, or bearing, end' of the cam activating screw 4E. The other end of the cam activating screw is threaded into.

f cam sheaves.

or' forces the vspindle downwardly:T against the pressure of the spring 43, or permits .the spindle',

to rise. under theveectof the. spring; pressure,

depending on the nature. of the. cam surfacewhich. is passing under the cam activating screw fat;

any particular instant.

Ordinarily, the camswill be alike on all ofthe work-supporting spindles anda preferred embodiment is illustrated. However, considerable variation in the amount and frequency of the vertical. movement. of the work. support. is:- possible simply by substituting one cam-faced sheave for another. Ifilsp'ecial circumstances-require it,

a'cam-faced sheave providing vertical movement.

of any work support. peculiarly suited to the operationbeing performedon the die which is mounted on that particular work support maybe selected. I i

Using a double'. cam-faced sheave such as/is shown in the illustrative embodiment, the work support will successively rise, dwell, fall, dwell, rise, dwell, fall, and dwell: in' one-turn o1' the spindle, and this series of steps will be repeated as the spindle continues to turn. The rise and fall intervals may each continue, for example, through 60' of rotation, and the dwell intervals may be 30 each. y

vBy watching the wear of any drilling needle as it is exposed during thel lowerV dwell periods, the operator can regulate the vertical? adjust-v mentof that needle, in manner hereinafter described, to secure Imaximum cutting and enicency. When the needle showsfexcessive wear, it should be lowered sufficiently tomaintain efficient cutting. This -individual ad-justability of the needles makes possible and facilitates the efficient performance of different operations simultaneously on a plurality of diamond dies by a single machine.

In an alternative form of cam, the work piece will rise and fall once, instead of twice, for each turn of the spindle, and it will be understood that other variations are possible. Also, the amount of the cam rise may vary on different In a cam of the preferred type shown in the drawings, a cam rise of threesixteenths inch is easily permissible with av cam sheave diameter'of three inches, and this provides efcient. operation.

The work-supporting spindle 32 will be rotated by a flexible band which engages the grooved rim of the cam-facedsheave 45. It will be desirable to provide. a common driving band for a.

ing band and the grooves in the sheaves will be Y cut deep enough to minimize any danger of the belt being thrown off unintentionally.

A considerable variation in the layout of the belt driving connectionsfor the work-supporting spindles of the machine of thepresent invention is possible. drilling spindle machine such as ishereinf described is disclosed iny Figure 4 of the application drawings, wherein the spindles are; driven as groups of four.

A Vbelt 5l extends around four ofthe camffaced.

sheaves 45, and around a step-down idler sheave 52. Conveniently the belt will be' tensioned by A preferred layout. for a. sixteen..

iarssure'eierted by the idler sheave 53. As may be seen in Figures 2 and 3, the step-down idler sheave52 comprises three axially aligned sheaves, all secured together so as to turn as one, one of the sheaves being larger than the other two.

' One of the two smaller sheaves Vserves to drive the belt 5|, and the other drives a similar belt 54 passing around another group of four camfaced sheaves 45. l

The larger sheave of the stepdown idler 52 is rotatably secured'on the lower end of a spindle 55, and the upper end of this spindle is secured, as by means of a set screw, in the boss 56 depending from the lower side of the sole 29. The belt tensioning idler sheave 53 may be rotatably mounted at one end of a short crank or lever, the other end of which is pivoted on a spindle secured in the boss 56 of an adjacent drilling spindle bracket. The desired tension in the belt may be attained by adjustment and setting of the crank on Vthe spindle, or continuously by spring pressure, in known manner.V y

The step-down idler sheave 52 is driven from the main drive shaft `I'I by means of a flexible band 53 passing around the larger sheave, through one of the openings 2l in the wall of the cylindrical member I8, and around a pulley 59 secured on the shaft I1. A V belt is suitable for this driving connection. Rotation of the main drive shaft I'I will cause the belt 58 to turn the step-down idler sheave 52 which, in turn, will cause the belts 5I and 54 each to rotate four of the cam-faced sheaves 45 and their associated work-supporting spindles 32. Y

Another pulley 59 on the main. drive shaft will cause the belt 58 to turn another step-down idler' sheave 52', similarV to 52, and in turn cause the belts 5I' and 54 each to drive four camfaced sheaves 45 with their work-supporting spindles.

Thus, all of the work-supporting spindles will be rotated upon rotation of the main drive shaft. With the particular driving layout illustrated, the work-supporting spindles all will be driven in the same direction and at the same speed. Some variation in the speed of the work-supporting spindles, in groups of four, is possible by the substitution of different step-down idler sheaves. 'I'he belts 58 and 58' passing through openings `'2I in the cylindrical member I8 do not,v of course, interfere in any way with turning the cylindrical housing I8-I9 on the turntable base II to bring any particular drilling spindle unit into position directly in front ofthe operator.

The main drive shaft I'I will be driven through suitable connection at its lower end to a motor or other source of power, not shown. Desirably, the weight of the shaft is borne by the bearing 60, supported by the bar I6 spanning the interior of the turntable base I I.

The high speed drill-carrying spindle 33, which is aligned with the work-supporting spindle 32, is mounted in the outer end of the upper sole 30 of the drilling spindle bracket, conveniently in a manner generally similar to that employed for mounting the Work-supporting spindle. The construction will be understood from Figures 1, 2 and 3 of the application drawings, to which reference is now made.

vThe thickened outer end of the sole 30 has a vertical bore to receive a flanged sleeve 62. This sleeve 62, which projects both above and below the sole, may be secured in the sole in the same manner that the flanged sleeve 4I is secured in the lower sole 29.

The upper end of the flanged sleeve 62 is split longitudinally on one side'for a short distance. and is cut transversely for a distance equal to approximately one-sixth of the circumference on each side of the longitudinal split, at the lowerV end thereof, to provide two ears which can be flexed slightly to exert a clamping action. A hand screw 63 is associated with the two ears in known manner for adjusting the clamping effect.

Within the bore of the sleeve 62 is a split bushing adapter 64, which desirably will be flanged at its upper end to prevent dropping throughV the sleeve; Slidably mounted Within the split bushing adapter 64 is a cylindrical housing 6I containing ball or other suitable high speed bearings for the drill spindle 33. When the hand screw 63 is tightened, the spindle housing 6I will be held firmly by the split bushing adapter against vertical movement. By loosening the hand screw it is possible to move the spindle housing 6I up orA down, and thus adjust the needle drill relative to the work support 42. Secured to the lower end of the spindle 33 is a chuck or other suitable means 65 for attaching a needle drill to the end dle 69, to which the rotatable core portion of theV shaft is connected. The housing 68 may be similar to the housing 6 I. l

The flexible shaft 66, connected at one Vend to a spindle housing adjustable in a horizontal plane and at the other end to a vertically adjustable spindle housing, should be trained so that adjustment of the spindle housings will not produce sharp localized bending of the shaft such as might interfere with its eilicient operation. 'Ihis result could be accomplished simply by separating the two spindles suiiiciently, but it is desirable, of course, to keep the overall dimensions of the machine small. In the machine of the present invention, the axes of the two spindles donot lie in a common plane and therefore the spindles may be mounted very close to each other and connected by the exible shaft arranged in the form of a loop, as shown in the drawing. Adjustment of the spindle housings merely increases or decreases the size of the loop slightly, which does not interfere with the efflcient operation of the shaft. At the same time, the machine is kept small in size.

As may be seen in Figure 6, the roller spindle housing 68 is slidably mounted in the transverse sleeve portion 'I8 at the upper end of the tubular support 'II One end of this sleeve portion is provided with clamping ears and an adjusting hand screw 'I2 similar to those on the upper end of the flanged sleeve 62. When the roller spindle housing is adjusted to the desired position within the sleeve 20, the hand Vscrew 12 may be tightened to clamp the housing 68'iirmly in the sleeve. 'Y

As can be seen in Figure 6, the tubular lower portion of the support 'II is slidably mounted in a boss 'I3 formed integral with and extending upwardly from the upper surface of the sole 30. The support 'II is resiliently held down in the boss 13, for example by a tension coil spring 'I4 lying withflexible shaft, is a roller 80.

' y'in "the, .tubular support and secured vat its 'upper end to the support and at'its lower end lto"v the y-sole'30.

Extending for a short distancedownwardly from the sleeve '70, the tubular supportl 1 lisslotted transversely as shown at 18 to permit passage of the'rod 15 therethrough without interfering with limited vertical movement of the support. One end of this rod 'l5 is rotatable in holes through thefupper end of the boss 13 and the other end is provided with a knob or handle'l so that the-operator of themachine can turn the rod readily.

Secured tothe rod 15 are two similar cams '11, one on each side of the boss 13. The edges Af these cams bear against the under side of the sleeve 10. As the rod 15 is turned, the cams vIl move the sleeve and connectedl support "Il upwardly against the tension ofthe coil spring 14, or permit the spring to draw the support down into the boss. The purpose of this adjustment is to make and break the driving connection to the roller spindle 69 and the iiexible shaft, as lwill appear hereinafter.

Secured on'the free end of the roller spindle 69, that is the end opposite the coupling to the The edge'of this roller preferably is rounded and is made of rubber or other material having a relatively high coefiicient of friction.

vWhen the rod is turned so that the .support 'Il is pulled down into the boss V'liby the spring '14, the vedge of the roller 80-willtbe pressedresi'liently'against the'top surface of .the horizontally disposed spindle driving disc 8l. 'Thisv driving disc preferably is made of phenolic :laminated materi-al such as is `soldunder the name Textolite, or similar non-metallic material, and is attached to the hub 82 which is secured on the upper end of the main drive shaft Il.

When the main drive'shaft I1 is rotated and the roller 80 is in Contact with the spindle driving disc 8|, the connection through-the flexible shaft 66 will cause the drill-carrying spindle 33 to be rotated. This driving connection may be broken'at the will of the operator merely by turning the rod 15 a half turn so that the cams 'Il lwill lift the roller spindle support and thus lift the roller 80 out of contact with the spindle driving disc 8 I. The speed of the drill-carrying spindle may be varied over a considerable range by loosening the hand .screw 12 and moving the roller spindle housing 68 in or out, depending on whether it is desired to decrease .or increase the spindle speed.

It will be obvious that the controls for each drill-carrying spindle of the diamond die making machine may be adjusted to the conditions best suited for the operation being performed .by that particular drilling spindle unit. The speed of each drill-carrying spindle may be varied without regard-t0 the speeds inthe other drilling 4units of the machine, and the driving connection to any particular drill-carrying spindle may .be brokenat the will of the operator Without interfering in any way with the operation .of the remaining drilling units.

The pressure of the drilling needle on vthe diamond die may be varied by adjusting the height of the drill-carrying spindle. This pressure also .may be varied by adjustment of the vcam-activating screw which bears against the cam-faced sheave on the lower end of the work-"supporting spindle. '.The reciprocating vertical movement. of the 'work-supporting spindle may be "varied by f ea fag-616,410

ysubstitution of one cam-faced sheave' for -another on thelower end of the spindle.

-It will be evident from the foregoing description that the operator will have complete control over all of the variable factors in the operation of the machine which affect the manufacture of a Wire `drawing die. That being thefcase, the procedure can be rsubstantially standardized, providing vfor. a given period of drilling under certain specified conditions, to be followed by another period of drilling under certain other specified conditions, and so on. Automatic timing mechanism 4may be employed in this connection. With the machine of the present invention it thus becomes possible for relatively inexperienced operators to produce'wire drawing dies 'of uniformly high quality expeditiously and efficiently. The objects of the' invention are accomplished.

"Theinvention herein disclosed maybe variously modii'led'and embodied within the scope of the subjoined claims.

"We claim:

l. Apparatus for the manufacture 'of wire drawing dies wherein an abrasive medium is applied to the point of a rotating needle-likedrill, comprising, in combination, a turntable base, a vertically disposed cylindrical housing 'mounted for rotation about its longitudinal axis on said turntable base, means for holding said' housing against rotation relative to the base at a plurality of 'positions of relative rotation, a plurality of 'spindle-supporting brackets secured to the'exterior `of-said housing and spaced around its periphery,

a vertical drill-carrying yspindle mounted in each bracket, a vertical work-holding spindle mounted in each bracket below andin alignment with the drill-carrying spindle,A a vertical drive shaft co-axially located within said housing, means for driving lthe drill-carrying spindles from said drive shaft regardless of ythe relative rotary position of the housing on the turntable base, the means for driving the drillcarrying spindles including means adjustable while `the apparatus is in operation for individually varying the speeds of the drill-carrying spindles, means for Adriving the work-holding spindles from said drive shaft regardless of the relative rotary position of the housing on the turntable base, and cam devices individual to said work-holding' spindles for.v reciprocatingV the work-holding spindles through short vranges along their longitudinal axes automatically as they rotate.

2. Apparatus for the manufacture of wire 'drawing 'dies wherein an abrasive medium is ap- Afor rotation about its longitudinal axis on said turntable base, means for holding said housing against rotation relative to the base 'at a plurality of positions of relative rotation, a plurality of drilling spindle units secured to Athe said housing and spaced around its periphery, each drilling spindle unit comprising a vertical drill-carrying spindle and a vertical work-holding spindle mounted below and in alignment with the drill-carrying spindle, a vertical drive shaft co-axially located within said housing, means for driving the drill-carrying spindles from said drive shaft regardless of the relative rotary position ofthe housing on the turntable base, .the means "for'driving the drill-carrying spindles including 'means' adjustable 'while :the "apparatus f is in operation for individually varying the speeds of the drill-carrying spindles, and means for driving the work-holding spindles from said drive shaft regardless of the relative rotary position of the housing on the turntable base.

3. Apparatus for the manufacture of wire drawing dies wherein an abrasive medium is applied to the point of a rotating needle-like drill, comprising, in combination, a turntable base, a vertically disposed cylindrical housing mounted for rotation about its longitudinal axis on said turntable base, means for holding said housing against rotation relative to the base at a plurality of positions of relative rotation, a plurality of drilling spindle units secured to the said' housing and spaced around its periphery, each drilling spindle unit comprising a vertical drill-carrying spindle and a vertical work-holding spindle mounted below and in alignment with the drillcarrying spindle, a vertical drive shaft co-axially located within said housing, means for; driving the drill-carrying spindles from said drive shaft regardless of the relative rotary position of the housing on the turntablebase, means for, driving the work-holding spindles from said drive shaft regardless of the relative rotary position of the housing on the turntable base, and cam devices individual to said work-holding spindles for. reciprocating the work-holding spindles through short ranges along their longitudinal axes automatically as they rotate.

4. Apparatus for the manufacture of` wire drawing dies according to claim 3, including, in combination, means adjustable while the apparatus is in operation for individually varying the speeds of the drill-carrying spindles over a wide range.

5. Apparatus for the manufacture of wire drawing dies according to claim 3, including, in combination, a friction disk and multiple roller transmission between the drive shaft and the drill-carrying spindles.

6. Apparatus for the manufacture of wire drawing dies according to claim 3, including, a combination, a friction-faced disk secured on the upper end of the vertical drive shaft, a plurality of driven rollers operatively associated with the said disk, one roller for each drill-carrying spindle, and driving connections between the said rollers and the drill-carrying spindles.

1. Apparatus for the manufacture of wire drawing dies according to claim 3, including in combination, a friction-faced disk secured on the upper end of the vertical drive shaft, a plurality of driven rollers operatively associated with the said disk, one roller for each drill-carrying spindle, and a flexible shaft connecting'each roller to the corresponding drill-carrying spindle.

8. Apparatus for the manufacture of wire drawing dies according to claim 3, including, in combination, a friction-faced disk secured on the upper end of the vertical drive shaft, a plurality of driven rollers operatively associated with the said disk, one roller for each drill-carrying spindle, a spindle for each roller, saidY roller spindles being disposed radially of the frictionfaced disk with the outer end of each roller spindle adjacent the upper end of a drill-carrying spindle, and a. flexible shaft connecting each roller spindle to the corresponding drill-carrying spindle, the said flexible shaft forming a loop.

9. Apparatus for the manufacture of wire drawing dies according to claim 3, including, in combination, a friction-faced disk securedl on the upper end of the vertical drive shaft, appluyrality of driven rollers `operatively associated Vadjustable while the apparatus is in operation for individually interrupting and remaking the ldriving connections between the disk-and the drill-carrying spindles.

10. Apparatus for the manufacture of wire drawing dies according to claim 3, including, in combination, a friction-faced disk secured on the upper end of the vertical drive shaft, a plurality of driven rollers operatively associated with the said disk, one roller for each drill-carrying spindle, means normally exerting a resilient pressure between the rollers and the friction face of the disk, means adjustable while the apparatus is Yin operation for individually lifting the rollers from-the disk and for-returning the rollers to engagement with the disk, and driving connections between the said rollers and thev drillcarrying spindles.v

11.r Apparatus for the manufacture of wire drawing dies according to claim 3, including, in combination, a plurality of sheaves secured on the drive shaft, a plurality of countershafts mounted exteriorly of the cylindrical housing, each countershaft having a sheave secured thereon and being connected by a belt extending through an opening in the cylindrical housing to one of the sheaves on the drive shaft, a sheave ysecured on each work-holding spindle, additional sheaves secured'on the countershafts, and belts connecting the latter sheaves to the sheaves on the work-holding spindles for driving the workholding spindles.

12. Apparatus for the manufacture of wire drawing dies wherein an abrasive medium is applied to the point of a rotating needle-like drill, comprising, in combination, a supporting member, a vertical drill-carrying spindle mounted in the supporting member, a vertical work-holding spindle mounted in the supporting member'below and continuously in axial alignment with the drill-carrying spindle, a drive shaft, driving connections between the drive shaft and each of the spindles for simultaneously rotating the two spindles in opposite directions, and a variable speed transmission in the driving connection between the drive shaft and one of the spindles, the said variable speed transmission including means adjustable while the apparatus is in operation to adjust the speed of the spindle to any speed between maximum and minimum without interrupting its rotation.

13. Apparatus for the manufacture of wire drawing dies according to claim l2, in which the variable speed transmission comprises a friction disk and roller withV meansfor adjusting the roller radially over the disk surface.

14. Apparatus for the manufacture of wire drawing dies according to claim 12, in which the variable speed transmission comprises a frictionk plied to the point of a needle-like drill, comprising, in combination, a supporting member, a vertically disposed spindle mounted in the supporting member and adapted to carry a work piece on the upper end thereof, the mounting for the spindle permitting limited reciprocatory motion of the spindle along its longitudinal axis, spring means normally urging the spindle upwardly, a cam-faced sheave secured on the lower end of the spindle with the cam face up, and means xed on the under side of the supporting member engaging the cam face for imparting a vertical reciprocatory motion to the spindle upon rotation thereof.

FRANK M. POTTER.

ROBERT M. HARTMAN.

14 REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS