US2689360A - Combined wire drawing and forging machine - Google Patents

Description

1954 B. F. WARE COMBINED WIRE DRAWING AND FORGING MACHINE Sept. 21,

Filed Feb. 9. 1950 2 Sheets-Sheet l Sept. 21, 1954 a. F. WARE COMBINED WIRE DRAWING AND FORGING MACHINE Filed Feb. 9. 1950 2 Sheets-Sheet 2 \\\\\\kr Wm. QIQ. A \m wMV////// R INVENTOR.

55 E W es BY 62 a Arm HEY-3 Patented Sept. 21, 1954 COMBINED WIRE DRAWING AND FORGING MACHINE Ben F. Ware, Euclid, Ohio, assignor to The Ajax Manufacturing Company, Euclid, Ohio, a corporation of Ohio Application February 9, 1950, Serial No. 143,305

2 Claims. 1

This invention relates to the fabrication of non-circular metal articles from drawn wire stock and, more particularly, to a novel method and apparatus by which the production of such articles from drawn wire stock can be carried out more satisfactorily and with more simplified equipment than has heretofore been possible. Although the invention is applicable to the production of various different metal articles of noncircular cross-section, it is particularly useful in the manufacture of nut blanks of polygonal shape and is accordingly disclosed herein as applied to that use.

It has been recognized heretofore that nut blanks of polygonal shape can be produced by using wire of a corresponding polygonal crosssectional shape as the stock from which they are to be fabricated. Such wire stock of polygonal shape has been produced heretofore by rolling and drawing operations but has always been subject to the occurrence of angular twist therein. Such twist usually results from minor irregularities or imperfections in the drawing dies or rolls and, so far as practical manufacturing operations are concerned, is unavoidable.

When such polygonal wire stock being delivered by the drawing dies or rolls is stored in coils for subsequent feeding to a fabricating machine such as a header, the twist present in the stock creates a very troublesome problem. In order to successfully feed such coiled polygonalstock to a header it has been necessary to provide a special holder for the coil and which holder had to be of occur frequently and cause expensive delays in the production operations of the header and in the other manufacturing operations dependent thereon.

The present invention entirely eliminates this difliculty and, as one of its objects, provides a novel method and apparatus by which drawn wire stock of polygonal shape can be used to advantage in the production of non-circular metal articles, such as polygonal nut blanks, without being concerned with the problem of twist.

' Another object of this invention is to provide a novel method and apparatus for the economical production of polygonal nut blanks of superior quality from drawn wire stock of a corresponding polygonal shape and in which the drawn polygonal stock is fed to a fabricating machine, such as a header, directly and at substantially the rate of production and with the drawn polygonal stock extending from the drawer to the header being of such short length. that the twist which may be present therein will be negligible.

A further object is to provide a novel method and apparatus for the production of non-circular metal articles in which wire stock of substantially round shape is subjected to an intermittent short-stroke drawing operation by a wire drawer located ahead of the fabricating machine or header to thereby convert the wire to polygonal shape at substantially the rate of production required by the header and in which the drawn polygonal wire is fed directly to the header from the-drawer with the strand of drawn polygonal stock passing therebetween being of such short length that any twist produced therein by the drawing operation will be negligible.

Other objects and advantages of the invention will be apparent in the following detailed description and in the accompanying drawings in which,

Fig. 1 is a side elevation showing wire drawing and fabricating apparatus for the production of polygonal nut blanks, or the like, according to this invention;

Fig. 2 is a partial plan view of such apparatus taken substantially as represented by line 2-2 of Fig. 1;

Fig. 3 is a diagrammatic view in the nature of a transverse section taken on a horizontal plane and further illustrating the wire drawing step and the article forming steps;

, Figs. 4 and 5 are transverse sections of the wire stock before and after the drawing operation thereon and taken, respectively, as indicated by section lines 4-4 and 5--5 of Figs. 2 and 3 but showing the stock on a larger scale;

Fig. 6 is a transverse section taken on section line 6-6 of Fig. 3 and further illustrating the drawing die;

Figs. 7 and 8 are side and plan views, respectively, of a slug sheared from the leading end of the drawn polygonal stock and prior to the first forming operation;

Figs. 9 and 10 are side and plan views, respectively, showing the shape of the nut blank after the first forming operation thereon;

Fig. 11 is a plan view of the nut blank after the second forming operation thereon;

Fig. 12 is a sectional view taken through the blank, as indicated by section lines I2I2 of Fig. 11;

Fig. 13 is a plan view of the nut blank after the piercing thereof;

Fig. 14 is a sectional view taken through the pierced blank, as indicated by section line I4I4 of Fig. 13;

Fig. 15 is a transverse section. similar to Fig. 5 but showing drawn polygonal wire stock of a different cross-sectional shape; and

Fig. 16 is a fragmentary View showing how transfer fingers will securely grip a polygonal slug or nut blank.

In Figs. 1 and 2 of the drawings the'improved apparatus I for carrying out the present invention is shown as comprising a wire drawing machine II which operates on rod stock I2 of round cross-sectional shape to convert the same into stock I3 of a polygonal shape, such as square or hexagonal, and a fabricating machine M, such as a header, to which the drawn polygonal stock I3 is fed directly from the drawing machine. The apparatus I0 also includes a feed mechanism I which is associated with the header I4 and driven thereby. The feed mechanism I5 includes a pair of cooperating feed rolls I6 and I1 which grip the drawn polygonal stock therebetween and intermittently feed it to the die mechanism of the header I4. The apparatus II] also includes a power transmitting device I8 which is driven by the header I4 andtransmits actuating movement to the drawer II- through the link IS. The rod stock I2 can be supplied from a coil or can :be in the'form of long straight lengths or bars of stock which are fed to the drawer in succession.

The drawing machine II is of the short-stroke type more fully disclosed in Patent No. 2,226,400, granted December 24, 1940. As is'understood by those skilled in this art, wire drawing machines of this kind when used in advance of a cold header size the wire stock and improve the character and strength thereof such that the articles produced by the header will be more regular and of higher quality. For the purpose of the present invention, the drawer I I need be only briefly described hereinas to its general construction and operation. This machine comprises :a frame 2i having stock gripping devices 22, 23 and 24 thereon and a reciprocable slide carrying a drawing die 26. The gripping device 22 is a drawing grip which holds the drawn stock against backward movement during 'the drawing operation performed thereon by the die 26. The gripping device 23 is an inching grip and the gripping device '24'is an inching feed device. The devices 23 and 24 constitute parts of' an inching mechanism by which the leading end of anew length of wire stock is started through the drawing die 25. The die slide 25' is moved toward the left, as seen in Fig. 1, through the drawing stroke by a lever 21 which is pivoted on the frame 21 and adapted to be swung, by the link I9, and is moved toward the right through a return stroke b the compression springs 28.

During the drawing stroke imparted to the slide 25. by the lever' 21, the drawing die 26 is pushed over the stock while" the latter is being held against backward movement by the drawing grip 22. When the lever 21 is swung in the opposite direction by the link I9, the die slide 25 and the die Zfiare returned by the springs 28 and during this return movement the drawn stock I3 is 4 gripped by the feed rolls I6 and I1 and fed to the die mechanism of the header I4.

An important feature of the drawing machine It is that the drawing die 26 has a polygonal orifice 29 therein which acts on the stock to convert the same from the round cross-sectional shape of Fig; 4 to the polygonal cross'sectional shape, in' this instance a square shape or a roundcornered square shape, as shown in Fig. 5. Although the round stock I2 is here shown as being converted to polygonal stock of a square crosssectional shape, it should be understood that a die could be used having an orifice which would convert the round stock to a hexagonal shape, as shown in Fig. 15, or to any other desired polygonal cross-sectional shape. Likewise, it should be understood that although the stock I2 fed to the drawer II is usually round stock as here shown, it could be stock of a round-cornered polygonal shape, such as round-cornered square stock or round-cornered 'hexagonal: stock.

The header i l is of the type used for carrying out pressure forming operations on metal blanks by cold working to produce the desired articles, such as the nut blanks referred to herein. This header comprises a frame 39 having a slide 3I reci'procably movable therein and-carrying a horizontally extending group ofdie punches 32, 33 and 34. The header I4 also includes a die block 35 having a horizontally extending row of stationary dies 36, 3 and 38 mounted therein so as to lie opposite to'and cooperate with the movable punches 32, 33 and 34.

The header Hi also includes a cut-off device comprising a hollow die member 39 through which the drawn polygonal stock I3 is fed by the feed rolls I6 and H, and a reciprocable cutter 40 which is movable transversely to the opening of the die 39 for shearing successive lengths or slugs M of stock from the'l'eading end of the wire being fed. As shown in Figs. '7 and 8 the slug M has substantially fiat end faces Ma and although itis generally square in plan shape it has rounded corners 4 I17. Additionally, the header M includes a suitable transfer mechanism which may be of the type shown in Patent No. 2,272,758, granted February 10, 1942, comprising pairs of cooperating fingers operable to-grip the slugs 4| and the blanks produced therefrom and to advance the same f-rom' the cut-off station to the successive forming and piercing stations. The transfer mechanism is represented herein only by the fingers 42 of Fig. 16 which have complemental corner-shaped recesses 43 therein.

An important feature of the present invention is that the square stock I3 produced by the drawing die 26 is supplied directly to the header I4 and at substantially the rate such square stock is being produced, and with the drawing machine II located relatively close to the header so that the drawn stock I3 extending therebetween is of such short length that any twist which has been imparted to the drawn stock by the die 26 will be negligible and will have no harmful effect on the operation performed by the header I4 or the nut blanks produced thereby. The spacing of the drawing machine I I ahead of the heading machine I4 will always be such that the portion of the drawn stock extending from the drawing die 26 to the cut-off die 4% will be not less than three feet long and not more than ten feet long. Within these limits the amount of twist occurring in the drawn polygonal stock I3 will be negligible since it will have no tendency to produce tangling or. jamming and will have no i and the stationary die. member 31.

harmful effect in the production of the completed nut blanks. The use of the polygonal die 26 in the drawer in combination with the rela- I tively closely spaced relation of the drawer to the header l4, eliminates the need for a special coil support for feeding poly onal wire stock to the header as already explained above, and also results in other important advantages which will be pointed out hereinafter.

As shown in Figs. 3 and 6 the drawing die 26 is so located that one pair of the corners of the drawn polygonal stock |3 issuing from the die orifice 23 will lie in a vertical plane and the other pair of corners will lie in a horizontalplane. This is important because when the slug 4| is sheared from the end of the stock by the cut-off die 40 it will be disposed with one pair of its corners lying in a horizontal plane which will permit this slug or blank to be securely gripped and held by the fingers 42 of the transfer mechanism and to be more accurately positioned when the slug is transferred from one station to another of the die mechanism of the header l4. This same advantage will be realized when the cross-sectional shape is that of a hexagon having one pair of its corners lying in a horizontal plane. Since the slug 4| can be thus more securely held by the fingers of the transfer mechanism, it can be more accurately located in front of and in register with the polygonal die recesses, in this instance square recesses, 36a, 31a and 38a of the stationary dies 36, 31 and 38. f

The punch members 32 and 33 also have polygonal die recesses 32a and 33a therein which in this instance are square recesses and cooperate with the polygonal recesses 36a and 31a of, the die members 36 and 31 when the punches are moved into closed relation to the latter die members. When the slug 4| has been transferred to the first forming station it is received in a die chamber formed by the polygonal recesses 32a and 35a and is subjected to forming pressure therein by the punch 32 and the stationary die member 35. During this forming operation the substantially flat-ended square slug 4| is converted into a partially formed nut blank 44 having its ends chamfered or domed, as indicated at 44a, and also having a more regular square shape but still having somewhat rounded corners 44b. The blank 44 resulting from the first forming operation is shown in Figs. 9 and of the drawings. i Thepartially formed blank 44 is transferred from the first forming operation to the second ,forming operation by the transfer fingers 42, and in the second forming operation is subjected to pressure in a square die cavity formed by the cooperating recesses 33a and 31a of the punch 33 In this second forming operation the partially formed blank 44 is converted into a partially pierced blank 45 having a regular square shape correspondingwith that desired in the completed nut blank. The blank 45 is illustrated in Figs. 11 and 12 andhas aligned recesses 46 and 41 extending thereinto from opposite ends thereof. The recess 46 is formed in the blank 45 by the reduced outer end 48 of a die pin 49 located in the punch member 33. The recess 41 is formed in the opposite end of the blank 45 by the reduced outer end 50 of a die pin 5| located in the stationary die member 31. The die pins 49 and 5| also serve as knock out members for disengaging the blank 45 from these 'die members.

The partially pierced blank 45 is transferred by the transfer mechanism from the second forming operation to a position located in front of the stationary die member 38 for the piercing operation. The piercing punch 34 advancing toward the stationary die member 38 moves the blank 45 into the die recess 38a and shears out the slug of the metal forming the wall portion 52 located between the axially aligned recesses 46 and 41. During the withdrawal of the piercing punch 34, the pierced nut blank 53 is withdrawn thereby from the die recess 38a and is stripped from the piercing die by a stripping plate 54. The completed nut blank 53 is illustrated in Figs. 13 and 14 of the drawings and now has a tap opening 55 ready to be tapped.

It is important to observe that in the forming of the nut blank 55 from the slug 4|, as described above, the blank is subjected to only two forming operations, namely those carried out as a first forming operation between the punch 32 and the die member 36 and the second forming operation carried out between the punch 33 and the die member 31. This is made possible by reason of the fact that the slug 4| is already of a polygonal shape corresponding generally with the square shape desired for the completed nut blank 53. Therefore, when the slug 4| is subjected to the forming operations to convert the same to the accurate square shape of the completed nut blank 53, only moderate pressures will be needed to produce the necessary displacement of metal and the shaping thereof to the domed shape of the blank 44 and the partially pierced shape of the blank 45. It will also be readily seen that in converting the blank from the initial rough square shape of the slug 4| to the more regular square shape of the domed blank 44 no excessive amount of metal need be displaced, such as would be the case if the slug 4| were of a round shape and were required to be converted to a rough square shape.

Similarly, in converting the domed blank 44 into the partially pierced blank 45, the corners of the latter blank can be fully and accurately filled out without requiring the displacement of any excessive amount of metal. Since the distribution of metal in the rough square shape of the slug 4| is more favorable to the produc tion of the partially formed blanks 44 and 45 by the above described pressure forming operations than in the case of a slug of round shape, it will be readily seen that the desired shaping of the blank can be accomplished with the application of ordinary die pressures in only two forming operations, Whereas to form around slug to the desired square shape. would require three pressure forming operations as has been well recognized heretofore in this art and, in addition, some or all of these three pressure forming operations require the use of very heavy die pressures which result in considerable wear on the dies making frequent replacement of the dies necessary.

From the accompanying drawings and the foregoing detailed description it will accordingly now be understood that the improved apparatus and method of this invention provide for the attainment of numerous important advantages in the manufacture of non-circular metal articles from drawn wire stock. Some of these advantages can be here summarized by pointing out that when the wire stock is drawn to polygonal shape and fed directly to the header with only a short intervening length of the drawn polygonal stock, the twist which can occur in 7. such short length of stock will be negligible and cannot cause snarling or jamming of the stock and also eliminates the need for any special coil such as is necessary when wire stock. is drawn or rolled to polygonal shape and then stored in coils before being fed to the header.

The-present invention also provides a slug of a; polygonal shape corresponding generally with the: desired non-circular shape of the article to be produced and this reduces the amount of work :needed' to be performed on the blank by the dies of. the header. This is in contrast to the manufacturing procedure heretofore fol lowed in which. a 'round slug. was cut-off and required a greater length of stock to provide the necessary amount of metal for the desired article and also required heavier forming pressures to be exerted by the dies and required a much greater amount of cold working of the metalrin order to-fill out the corners of the noncircular shape of the finished article. Since this improved apparatus and method requires less working of the metal by the dies, the work performed by the group of dies can be more evenly distributed and rapid die wear on any on die is prevented. If the three forming steps ordinarily used heretofore in producing nut blanks of the type herein disclosed are employed, the work required to be performed by this number of forming dies will not be burdensome on the dies and a correspondingly long die life will result. On the other hand, this improved method and. apparatus permits at least one of the'previ'ously used forming steps to be omitted without subjecting the dies to excessive working; pressures and this represents a decided saving in die cost.

It should also be mentioned that the stock I2 being supplied to the drawer H can be round stock which has been previously drawn and which requires a further drawing operation to reduce it to proper size and cross-sectional shape for proper fabrication in the header l4.

It is also an important advantage of this improved apparatus and method that a change from one size of stock to another can be readily made because it is only necessary to substitute another die 2 5 in the drawer H and the amount of drawn stock which will be wasted in making such a change will be only the few feet extending between the drawing die and the header. Another important advantage is that the drawn polygonal stock being supplied to the header will not bind in the feed quill because the short length of such drawn stock will be devoid of any appreciable twist such as is unavoidably present in previously drawn and coiled stock and has heretofore caused troublesome binding in the feed quill.

Additionally, it will be seen that the polygonal stock will cut off much better than round stock because a different and more advantageous distribution of stresses occurs during the shearing action performed by the knife of the cutoff mechanism. Still another advantage achieved in the improved apparatus and method is that the blank-gripping fingers of the transfer mechanism will be able to hold the polygonal slug more accurately and securely than a round slug and to locate such slug more accurately with respect to the forming dies.

Although the improved apparatus and method of this invention have been illustrated and desoribedherein to a somewhat detailed extent, it should be understood that the invention is not to be regarded: as being limited correspondingly in scope but includes all changesv and modifications coming within the terms of the claims hereof.

Having thus described my invention, I claim:

1. In apparatus for the fabrication of noncircular metal articles from wire stock by-cold working a fabricating machine of the cold-header type having cut-off dies operable on polygonal cross-section Wire stock for severing successive sections from the leading end thereof and a horizontally extending row of forming dies provided with polygonal diev recesses for shaping such sections into nut blanks of'polygonal shape, a wire drawing machine. head of said fabricating machine and including a drawing die having a die passage of polygonal shape and operable by successive short-stroke drawing operations to convert circular cross-section wire stock into drawn wire stock of such polygonal crosssection, feeding means operable to feed the drawn polygonal stock fromsaid drawing die to said fabricating machine directly and at' substantially the rate of production thereof, said fabricating machine being located relatively close to said drawing machine and the drawn polygonal stock passing directly therebetween being of such short length that any twist introduced into the stock by irregularities of the drawing die will have negligible interference with the operation of said fabricating machine, said forming dies and said drawing die all being disposed such that a pair of the opposed corners of the polygonal shape thereof lie substantially in the same horizontal plane, and transfer means associated with said cut-off and forming dies and having blank grippin portions of angular shape engageable with said pair of opposed corners of the blanks for secure holding and accurate positioning of the blanks during the transfer thereof.

2. In apparatus for the fabrication of noncircular metal articles from wire stock by cold Working, a drawing die having a drawing orifice of polygonal shape at the outlet end thereof, frame means supporting said drawing die for short-stroke reciprocating drawing movements, means adapted: to supply stock to, said drawing die, means operable to impart said drawing movements to said drawing die for causing the latter to convert said stock to drawn stock 'having a polygonal cross-sectional shapecorresponding with the polygonal shape of said drawing orifice, a group of dies including a cut-off die operable to sever polygonal blanks from the drawn polygonal stock and a horizontally extending row of forming dies operable on said polygonal blanks and having polygonal die recesses for producing non-circular metal articles from said blanks, other frame means supporting said group of dies, means operable in said other frame means for causing such actuation, of said outoff and forming dies, feeding means located between the first-mentioned frame means and said other frame means and being operable to feed said drawn polygonal stock directly from said drawing die to said group of dies, said group of dies being located relatively close to said drawing die and in such proximity thereto that any twist introduced into the drawn polygonal stock during the drawing thereof will be negligible with respect to the functioning of said feeding means and said group of dies, said forming dies and said drawing die all being disposed such that a pair of the opposed corners of the polygonal shape thereof lie substantially in the same horizontal plane, and transfer means associated with said cut-ofi and forming dies and having blank gripping portions of angular shape engageable with said pair of opposed corners of the blanks for secure holding and accurate positioning of the blanks during the transfer thereof.

References Cited in the file of this patent UNITED STATES PATENTS Number Number 10 Name Date Sharp Mar. 10, 1931 Hague Nov. 7, 1933 Hogue Nov. 2'7, 1934 Richardson Nov. 27, 1934 Harvey et a1. Sept. 24, 1935 Hogue Oct. 22, 1935 Frayer Apr. 20, 1937 Frayer May 18, 1937 Clouse Sept. 3, 1940 Gaines Dec. 24, 1940

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