US2017309A - Method of and apparatus for manufacture of bolts, rivets, and like articles - Google Patents

Description

Oct. 15, 1935. J. H. FRIEDMAN 9 I METHOD OF AND APPARATUS FOR MANUFACTURE OF BOLTS, RIVETS AND LIKE ARTICLES Filed May 4, 1954 2 Sheets-Sheet 1 Qttorneg J. H. FRIEDMAN METHOD OF AND APPARATUS FOR MANUFACTURE OF BOLTS, RIVETS AND LIKE ARTICLES Filed May 4, 1934 2 Sheets-Sheet 2 Oct. 15, 1935.

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Zirwentor I (Ittorneg ?atented @ct. i5, 3%35 John H. Friedman,- 1 its National Machinery @ompany,

corporation of @hio Ghio, assignor to The 'liimn, iihio, a

Application May i, 1934, Serial No. $723,933

12 Claims.

This invention relates to the manufacture of bolts, nuts, rivets and like metal articles which are shaped from suitable blank lengths sheared from wire or rod stock and then subjected to an upsetting or forging operation.

In the manufacture, of bolts and nuts by cold working, it has been customary to purchase rolls use in cold headers for making bolts, or machines for making nuts by cold working, due to variations in size and shape and surface imperfections. Intermediate handling of the material between the drawing operation and the upsetting operations is necessitated by the fact that the wire drawing machines operate continuously whereas the bolt and upsetting machines, which commonly embody or are associated with shears for severing the material into blanks of the desired size, operate with an intermittent stop feed. As a result, it is necessary to coil the wire as it leaves the drawing machine and feed the wire to the upsetting machines from the coils so formed.

The present invention is directed primarily to a process permitting the elimination of the usual ,vention which may be utilized either in com- I wire drawing operation and intermediate handling so that bolts, nuts and the like may be made i by cold working directly from continuous lengths of hot rolled rod stock, and apparatus for carrying out this process. Generally speaking, the process of the present invention consists in sizing and finishing the rough rod stock by intermittent extrusion or drawing in timed relation to the shearing of the stock into blanks to be upset, and also preferably in timed relation to the upsetting of the blanks. Specifically, my invention includes as alternative embodiments the shearing off of blanks from the continuous rod stock, force ing the blanks through an extrusion die and feeding the same to the upsetting dies; or feeding the rough rod stock through a pair of aligned bushes, one of which acts to extrude or draw the stock, moving the bushes relative to each other to shear off a blank and subsequently upsetting the blanks. Other features of the processof my'in- 'bination, as in the preferred embodiment, or

independently with-other operations, include the completion of the shearing, sizing and finishing operations by forcing a sheared blank-throughthe various parts of the apparatus by the advancing end of the next blank or the stock, and gene erally, the intermittent feeding of stock through a sizing and reducing die by the feeding means for the shear mechanism operating in timed relation to the shear mechanism. -My invention also includes in its preferred embodiment for the i0 manufacture of bolts, shearing on blanks from continuous rod stock, transferring the blanks into alignment with an extrusion die, forcing the blanks through the extrusion die by an ejector operating in timed relation to the ejectors for is the upsetting dies, transferring the extruded blank to the upsetting dies, and completing the formation of the bolt blank by cold heading, preferably in the manner disclosed in the copending application of Earl R. Frost, Serial No. 639,054, 20 filed October 24, 1932. Subject matter relating to the present invention is disclosed and claimed in the co-pending application of Norman W. Cummins, Serial No. 583,421, filed December 28, 1931.

My inventionalso includes the combination of 25 any of the above embodiments of the process of reducing rod stock and shearing off finished blanks with the steps of extruding the portion of the blank to the pitch diameter of the threads to be rolled thereon and upsetting the head of the blank either by single or double extrusion as disclosed in the abovereferred to application of Earl R. Frost.

' Amongthe advantages of my invention are. economy of manufacture resulting from the elim- 35 ination of the cost of separate wire drawing machinery and intermediate handling of the material, the removal of any roughening of the end of the sheared blanks resulting from the shearing operation when the drawing or extrusionis per- 40 formed subsequently to the shearing, and greater accuracy resulting from the correlation of one machine of the sizing and finishing dies and the shearing and upsetting dies.

The drawings illustrate certain types of apparatus which. may be usd for carrying out the method, and wherein: g

Figure 1 is a fragmentary plan view of the forward extremity of a bolt-making machine, showing means for feeding rough stock into the machine, shearing the stock into blanks, extruding the blanks and thereafter forming the blanks into the desired shape, the header slide being in advanced position;

- Figure 2 is a view in elevation of theapparatus of Figure 1 taken on the line 2- -2 of the latter figure;

Figure 3 is a view similar to Figure 1, showing the parts in the positions they assume when the v guide bush, and stock-advancing or feeding mechnoted above.

anism;

Figure 5 is a view in end elevation of Figure 4 as indicated by the line 55 of the latter figure; 7 Figure 6 is a sectional view of the shear bush and guide bush of Figure 4, showing the parts in cut-off or shearing position; a 7,

Figure 7 is a central longitudinal section through a shear bush and extrusion bush showing a reversal of parts relatively to Figure 4.

The apparatus for practicing the method of this invention is illustrated in Figures 1, 2 and 3 in conjunction with fragmentary portions of a bolt making machine of the type disclosed in the said application, Serial No. 639,054, filed October 22, 1932, solely by way of illustration, and not as a .limitation. In these figures, 5 designates a bed frame, 6 a header slide, and I a die breast in which are mounted dies 8, 9"and Ill. The die 8 is an extrusion die into which bolt blanks are pressed by a punch I l on the header slide to extrude the shank portion of the blanks; the-die 9 is also an extrusion die for extruding the threadreceiving portion of the ,bolt shank which is pressed into the die by a punch l2 on the header slide 6, which also heads the previously unextruded portion of the blank; while the die l0.is a holding die'which co-operates with a hollow trimming punch l3 on the header slide, which trims the upset heads of the blanks to the desired polygonal form. Suitable mechanism is provided to transfer blanks from the position to which they are fed at the completion of the'sizing operation to the first die 8, then to the die 9 and finally to the die I 0. Any desired type of transfer mechanism may be used, such for example as that shown in the aforesaid application of Frost or the transfer mechanism illustrated and claimed in the co-pending application of William L. Clouse, Serial No. 670,108,fi1ed May 9, 1933. The transfer mechanism is indicated by the pairs of springclosed fingers l4, l5 and I6 mounted on a horizontally and vertically movable carriage II." The carriage I! may be actuated by any suitable mechanism, not shown, but which can'be readily understood by referring to the co-pending application In the apparatus illustrated in Figures 1, 2 and 3, rough hot rolled rod stock S is fed by feeding rolls, a fragment of which is shown at l 9, through the frame of the machine, and through a suitable guide bushing 20.

When the desired length of stock to form a blank has been advanced through the bushing 28,

" the forward motion of the stock ceases and the blank is sheared off by any suitable type of shear mechanism. As illustrated, an oscillating arm 2 I,

it is allowed to return to its initial'posit'ion. The severed blank remains gripped in the fingers 22a. and the arm 22 continues to rock until the blank carried thereby is aligned with the extrusion die orbushing l 8. During theshearing action and the 5 transferring of the blank by the fingers 22a into alignment with the die Hi, the header slide 6 has been advancing. As the header slide starts to recede, a push rod 23 aligned with the die I8 is pressed forwardly by a lever 24 mounted on the 10 shaft 25, forcing the blank held by the fingers 22a into the die. During this time the stock S is again fed forwardly through the guide bushing 20. As

soon as the blank held by the fingers 22a has entered the die or bushing I8, the arm 22 is re- 15 slide 6 completes its rearward movement and again starts forwardly, the two arms 2| and 22 25 are again actuated together to cut offthe projecting end of the stock and carry the same over into alignment with the die l8. The push rod 23 preferably extends only a short distance into the extrusion die l8 and is then withdrawn. When 30' between the fingers H, the transfer mechanism operates to carry the fingers l4 into alignment with the die 8, at which point the blank is held 40 until the header slide on its next advancing mpvement presses the blank into the die 8.

The die I3 is constructed with a reduced shoulder l 8a preferably intermediate its length so that as a blank is pressed through the die it is ex- 45 truded slightly to reduce the blank to correct size and shape, and remove any surface imperfections. During this operation any rough edges or projections formed on the end of the blank by the shearing operation are removed and forced into align- 50 ment with the external cylindrical surface of the extruded blank. When the invention is employed in connection with the type of machine disclosed in the aforesaid co-pending application of Earl R. Frost, or with any other multiple die machine, 55 the blank after being acted upon by the punch ll in the die 8 is ejected from the die 8 when the header slide recedes and is transferred by the fingers 15 to the die 9. Similarly the blank ejected from the die 9 is then transferred by the fingers 60 IE to the die Hi. All of these operations take place during each stroke of the header slide so that when the header slide advances a new blank is sheared off and the three blanks held by these fingers ll, l5 and I6 are pressed into the dies 8, 9

and Ill, respectively, and as the header slide recedes the blanks are ejected from the dies 8, 8 and Ill and the push rod 23 simultaneously operates to complete the extrusion of the blank positioned in the die l8 by pressing the next blank into the die. At this time the fingers l4, l5 and l6are in alignment with the dies l8, 8 and 9 respectively, and receive the blanks ejected from thesedies and carry each blank to the next die position.

aoitgsoe It will be understood, of course, that the die 8 to which the blank is carried from the extrusion die it could be of any suitable typeand could be the blank-receiving die of a single stage heading machine. Similarly, in the case of the manufacture of other articles than bolts, the dies to which the blanks are transferred after being extruded through the extrusion diemay be'of any type necessary to carry out the desired operations.

It will be seen that the finished article is made directly from rough hot rolled rod stock in one continuous process. Since the drawing or extruding of the stock is accomplished in the extrusion bush it, the wear on this bushing will be uniform with respect to the die t. Furthermore, labor incident to the separate drawing operation is entirely dispensed with.

In Figure 4, the rod stock S is intermittently advanced by a clutch type feeding mechanism,

generally indicated at C, and comprising a housing 26, reciprocating wedges 2! and 21a, and

' clutch blocks 28 which move with the reciprocating wedges 2i and 21a. Connecting rods 29, 29a

and 30 are operatively connected to the clutch wedges 2i and 21a and the blocks 28 extend to suitable actuating cam mechanism, not shown. As the clutch wedges 2i and 21a move forward, they exert a wedging action on the blocks 28 which grip the stock and carry it forward the desired length of the blank. On the return stroke, the wedges M, 2m release the blocks 28 and the latter are returned to retracted position through suitable means acting on the connecting rod 30. This type of feed is accurate and dispenses with the conventional stock gauge used in most heading and bolt-making machines for accuratelydetermining the lengths of the blanks.

. In this instance, the stock is pushed through a suitable guide bush 3! held in place by means of is shown in Figure 5 and consists of a cam 3t mounted on a cam shaft 35, a spring 36 serving to return the arm to its original position.

It will be noted that in this instance the stock is intermittently advanced by the clutch mechanism generally indicated at C, which mechanism replaces the push rod 23 and cam. 26 in Figure 1. As the stock is pushed through the guide bush ti and extrusion bush ma, the cut-E arm tie is, oscillated by means of cam 35 and moves to a p0--v sition substantially as shown in Figure 6 to shear the blank. The arm Zia then moves back to the position shown in Figure 4 in alignment with the bush ti, and the next forward advance ofthe stock pushes the blank through the extrusion die ready to be taken by the transfer fingers i 6 shown in Figure 2. This method of shearing and extruding has the advantage in that it cuts the ends of the blank flush and does not leave any irregular contours around the end of the blank ordinarilycaused by shearing in the conventional type 'of heading or forging machine. In Figure 7, the method is substantially th same as in Figure a, with the exception that the extrusion bush 58b is held stationary while the guide bush tie is carried by the or cutofi arm 2 la. The means for advancing the stock may be substantially the same as that shown at C in Figure 4, and likewise the means for oscillating the cut-off arm may be the same as that shown in Figure 5.

The foregoing mechanisms are illustrative'of' various forms of means for carrying out the method, it being understood that these mechanisms may be varied within the scope of the invention as defined by the appended claims. 10

I claim:

1. In the manufacture of bolts, rivets and'like metal articles, the process which consists in the steps of shearing rough wire or rod stock into suitable blank lengths, passing the blanks com- 'pletely through a, reducing die to obtain the desired blank diameter, and upsetting the blanks to head the, latter. v

2. In the manufacture of bolts, rivets and like metal articles, the process which consists in forcefully passing rough hot rolled wire or rod stock through aligned guide and extrusion bushings, moving one bushing relatively to the other to shear the stock into suitable blank lengths, and then upsetting the blanks to head the'latter.

3. In the manufacture of bolts, rivets and like metal articles, the process which consists in forcefully advancing rough hot rolled wire or rod stock through aligned guide and extrusion bushings, interrupting the advance of the stock and moving one bushing relatively to the other -io shear the stock into suitable blank lengths,

blank through said die, and means for upsetting the blank.

5. In a bolt making machine, a shear, an extrusion or drawing die carried by said shear, a guide bush adapted to co-act with said die and shear, means for advancing rough wire or rod stock through said bush and die, means for actuating said shear to sever the stock into suitable blank lengths, and means for -upsetting the blanks.

6. The method of producing cold upset products which comprises intermittently feeding a predetermined distance, substantially round hot rod-stock of indefinite length and having a greater cross-sectional area than the cross-sectional area of the bodyof the finished products, sue-- to cessively transversely cutting ofi sections of the fed stock, extruding and reducing the crosssectional area of the entire length of the cut-0K sections, transferring said reduced cut sections transversely to other instrumentalities and opert5 ating on the cut sections by exerting pressure longitudinally thereon. v 7. The method of producing cold upset products which comprises intermittently feeding a predetermined distance, rod stock of indeterminate'length having a greater cross sectional area than the cross sectional area of the body of the finished products,; acting on said rod stock to form cut-off blanks extruded throughout their. length and trerring said blank to other in- 4 strumentalities andworking the blanks in said instrumentalities by exerting pressure longitudinally thereon.

, -8. A unitary machine for.producing a cold formed product directly-from crude rodstock of indeterminate length, a movable sizing die,-means to effect a relative movement between said die and stock to reduce the diameter of the stock, means for cutting oil? portions of said stock and means for transferring cut-ofi portions to other instrumentalities for further treatment before delivery from said machine; each of the said three means being an organized part of said uni- ,tary machine. 1

9. In a bolt making machine, a stock guiding bush, a shear member having a bore therein arranged to be aligned with said stock guiding bush, an extrusion die in said shear bore spaced from the shearing face of the member, means to move stock through said bush and shear, means to actuate said shear member and cut ofi a bolt lank extruded through a portion of its length and means to move said blank through said extrusion die to produce a blank extruded throughout its length.

10 The method of producing cold upset products which comprises intermittently feeding a. predetermined distance, substantially round hot rod-stock of indefinite length and having a greater cross-sectional area than the cross-sectional area of the body of the finished products, successively transversely cutting oiI sections of the fed, stock, extruding and reducing the crosssectional area or the entire length of the cut-ofl. 5

sired blank diameter, further extruding the resulting extruded and sheared blank to form a 15 thread receiving portion thereon, and upsetting the blank to form a head thereon.

12. A unitary machine for producing a cold formed product directly from elongated rod or wire stock material, means to. shear said ma- 20 terial into blank lengths and means to extrude said material to uniform blank diameter throughout its length, means to transfer the extruded out 01f blanks to work stations, reciprocating tools to work said blanks at said work stations, said-25 shearing means and said extruding means operating in timed relation to said reciprocating tools.

JOHN H. FRIEDMAN.

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