US2507817A - Method and apparatus for heating and forging elongated metal blanks - Google Patents

Description

May 16, 1950 2,507,817

E. ROPP ET AL METHOD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS '7 Sheets-Sheet 1 Filed Dec. 9, 1947 IRWIN ROPP WILBERT S. BLACKSTONE May 16, 1950 i. ROPP ET AL 2,507,817

METHCD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS Filed Dec. 9, 1947 '7 Sheets-Sheet 2 I32 I22 I27 55 II is 7 IRWIN ROPP WILB ERT S, BLACKSTONE May 16, 1950 l. ROPP ETAL 2,507,817

METHOD .AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS Filed Dec. 9, 1947 '7 Sheets-Sheet 3 awuam tm IRWIN ROPP WILBERT S. BLACKSTONE May 16, 1950 E. ROPP ET AL 2,507,817

METHOD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS 7 Sheets-Sheet 4 Filed Dec. 9, 1947 IRWIN ROPP WILBERT S, BLACKSTONE May 16, 1950 1. ROPP ET AL 2,507,817

METHOD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS Filed Dec. 9, 1947 7 Sheets-Sheet 5 Ill! ROPP BLACKSTONE IRWIN WILBERT S,

May 16, 1950 I. ROPP ET AL 2,507,817

METHOD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS Filed Dec. 9, 1947 '7 Sheets-Sheet 7 5 o- K J A 3o| 206 x 280 JPWQ/MO'L IRWSN ROPP WILBERT S. BLACKSTONE fatented May 16,

UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR HEATING AND FORGING ELONGATED METAL BLANKS Irwin Ropp, New Bedford, Pa., and Wilbert S. Blackstone, Youngstown, Ohio Application December 9, 1947, Serial No. 790,606

18 Claims.

:zIBgiOIls where deforming is to take place and in 10 this manner we effect economies in the heating Qof the blanks and materially reduce the scale Floss normally incurred in metal and forging oper- ;:ations. Further, since only spaced portions of rthe blanks are heated each of the blanks present (at least one substantial region of cold strong steel {capable of being very rigidly gripped by clamping means in the forging machine whereby the durability and reliability of the operation of such .forging means is materially increased. It is accordingly a primary object of the invention to provide an improved method of producing forged spikes, bolts and similar articles wherein definite economies and operational advantages are obtained through the heating of only those portions of the stock blanks which are to be deformed in the manufacturing process.

A more specific object of the invention is the provision of an improved method and apparatus for producing railroad spikes and the like of good quality and at a high rate of production wherein the latter advantage is obtained through the use of stock blanks each of a length sufiicient to produce two of the articles and wherein the blanks are heated only at their center and end portions to facilitate their retention in a clamping and pulling device while the end and center portions of the blanks are readily formed into the upset heads and pointed ends of two articles for each blank.

A further obu'ect of the invention is the provision of an improved method and apparatus :for hot-forging railroad spikes and the like wherein the heating required for each blank is accomplished in a very short interval of time and is limited to those regions which are worked in the forming process whereby the formation of scale is minimized and whereby the locally heated blanks are fed to the forging machine in a clean and bright yet strong condition to materially facilitate the forging operation. Further, the substantial elimination of scale from the forging apparatus is highly advantageous in insuring uninterrupted operation of the machine over long periods of service.

a; mechanical power source.

Yet another object of our invention is the provision of an improved spike forging and formin machine wherein a pair of completely formed spikes may be expeditiously formed from each of 5 a succession of elongated blanks of uniform crosssection. Thus, through the employment of an improved method and apparatus our invention enables high quality spikes to be rapidly produced from simply formed blanks.

A further object of the invention is the provision of an improved spike forging machine wherein an elongated stock blank is securely gripped at longitudinally spaced points and while so gripped has both its ends upset to form the 15 heads of two spikes after which the blank is deformed between the clamped portions and pulled apart to form the pointed end of two spikes. This arrangement makes maximum use of the parts of the machine and enables the spikes to be formed at a high rate of production.

Further, since both ends of the blank are simultaneously upset the forces opposing the upsetting operations oilset each other within the blank and consequently the gripping or clamping need not be so severe as is the case in more conventional machines.

Other objects of the invention include the provision of an improved spike forging machine wherein all of the stock-engaging and working a components are assembled in depending relation to receive a stock blank fed vertically upward whereby any scale spalled ofi during the forming operation will fall down free and clear of the operative parts of the machine. Also included a is the provision of a materially simplified yet rugged and durable machine for forming railroad spikes and the like wherein all the sequential operations necessary to be performed'on a stock blank are timed through the use of a unitary A still further object of the invention is the provision in apparatus for producing railroad spikes and the like of an improved arrangement for heating the blanks, of an improved apparatus 4' for feeding blanks consecutively into the heating means, and of an improved device for feeding heated blanks into the working area of the assembled apparatus.

The above and other objects and advantages 50 of the invention will become apparent upon con- 88 Figure 1 is a plan view of the apparatus of the invention including preferred blank heating and feeding arrangements;

Figure 2 is a perspective view of the heating device of the present invention;

Figures 3, 4 and 5 are perspective views of the product of the machine of Figure 1 at successive stages in its operation;

Figure 6. is a horizontal section of the machine of Figure 1;

Figure 7 is a side elevation of the machine of Figure 1;

Figures 8, 9, 10 and 11 are sectional views taken respectively at lines VIII-VIII, IX-IX, XX, and XlXI of Figure 6;

Figure 12 is a plan view, on an enlarged scale of a portion of the machine of Figure 1;

Figure 13 is a side elevation of the portion of the machine illustrated in Figure 12;

Figure 14 is an enlarged fragmentary view of the device of Figure 13 and illustrates the mechanical action thereof;

Figure 15 is a time graph showing the mutual relation existing between the several operations of the machine of the invention;

Figures 16. and 1'? illustrate the physical. motion of several of the improved mechanisms Within the machine; and

Figures 18, 19 and 20 are schematic showings of a modified form of spike forging machine con.- structed in accordance with the principles of the invention.

Referring now to the drawing. more in detail it will be observed that the spike making machine proper is supported upon and contained within a structural steel weldment comprised of the base Iebeams is and H, lower and upper cross beams l2 and i3 respectively, vertical corner beams 14 and upper longitudinal beams l5. One extremely deep I-beam iii replaces the vertical corner beams H1. at the left end of the machine as viewed in Figure 7.

A floating belt tensioner H is mounted on the upper beams is to support an electric motor [8, power from which is transmittedthrough pulleys I9 and 253 and multiple V-belts 21- to the mechanism proper which presently will be described in detail. An electrical switch 22 (see Figure 6) is incorporated in the machine and is arranged to successively make and break a suitable series of contactors (not shown) once upon each cycle of operation of the mechanism. This primarily establishes an index for the operation of the feeding mechanism nowto be described.

Attention is directed to Figure 1 wherein the spike making machine proper has in association asupply device 23, a feeding assembly 24, a heating assembly 25 and a feed conveyor 28. A supply of suitably prepared. elongated square steel blanks 3B are held in readiness within a feed hopper, not shown, and are fed by gravity onto a horizontally disposed walking beam conveyor 3|. A motor 32 operates conveyor 3] continuously to keep a steady supply of blanks 3 0 traveling outwardly of conveyor 3! and against a stop 33 where the headmost blank 3!] is held in readiness for the next succeeding operation.

Upon the periodic operation of switch 22 a feed solenoid 34 is actuated and through suitable linkage 35 operates to move a pusher 36 forwardly against the blank 39 which is currently at rest against stop 33. The said blank is thus urged forward axially into the heating assembly 25. Upon completion of its forward travel pusher 36 is caused to return to its retracted position by the timed energization of a return solenoid 31 which is also under the control of switch 22 and which operates in opposition to solenoid 34 described above.

The heating assembly referred to generally by the numeral 25 is an electrical induction heater of the intermediate frequency type which is well known in the electrical heating art and which need not be described in detail. Its energy is applied to each successive blank 30 as the blanks are moved forwardly into the induction loops 38, 3 9 and 40. The potential supplied to these loops is of such magnitude and frequency that proper heating takes place in the encircled blank 30 in the allotted time during which it remains at rest. The first coil 38 and the rear coil 40 each heat an end of the blank for the subsequent heading operations while the center coil 39 heats the center portion of blank 30 so that the subsequent forging and stretching operations at this portion may be readily effected.

Switch 22 is energized to initiate a repetition of the feeding cycle outlined above and the blank 3.0 which has been last heated is sent axially forward down the roller feed conveyor 25 toward its next station in the cycle of operation of the machine. Attention is directed to Figures 3, 4 and 5 for a graphic showing of the steps which subsequently occur in operating on the previously heated blank 30.

Figure 3 shows the blank 30- after heads 42 have been forged upon. each end thereof. The designing of these heads is beyond the purview of the present invention, it being obvious that the configuration thereof, will depend largely upon the shape of forming dies used. It will be ap-. parent however, that such heads as the ones illustrated, wherein there is a marked thickening or upsetting as at 42, may be most advantageously fabricatedin the machineof; the present invention. Since considerableaxial thrust must be exerted by the heading dies. upon the square ends of the rough blank 33 in order toforce the parent metal back upon itself and thus to swell out and form the head 42 and the upset 42, it will be. apparent that quite stringent clamping action would have to be applied throughout the center portion of the blank 3Qif it were to be held securely enough to resist a single-ended blow, By applying the principles of the. present invention it is possible tohold the blank 30 witha less severe force since the opposite heads. are formed simultaneously by oppositely directed blows of the forging, dies.

Following the heading operation the machine of our inventionprogresses topartially form the points of and to partially sever the two spikes ap proximately as shown in Figure 4. The, two clefts 43 and 43 extend into the body of, the blank on opposite sides thereof, to such a depththat a web 43" of parent metal of the thickness. of, the orderof /32" is left joining the two halves. Immediately upon withdrawal of the severing dies the two halves of the bar are drawn apart as indicated and the joining web 43 is drawn out extremely thin before it finally ruptures. The sharp edge 44 thus produced constitutes a relatively sharp penetrating point uponthe finished spike.

In. further disclosing the mechanical details of the machine of the invention attention is directed to Figures 1 and 7 wherein it will be observed that the pulley 20 mentioned supra is carried upon a laterally extending driven shaft 45 which projects from a worm gear reducer unit 46. A continuation 45' of shaft 45- extends toward a second gear reducer 41 whose shaft 48 is in turn extended. toward shaft 49 of a third gear reducer 50. The several gear reducers mentioned are all secured to the underside of one of the upper. side beams l of the machine frame. Flexible couplings 5| are used at appropriate places to. make the shafts 45, 48 and 49 substantially continuous and thus to impart power to the. several gear reducers 46, 41 and 58 simultaneously. The output shafts 52-, 53 and 54 of the gear reducers 46, 41 and 58, respectively, are disposed transversely of the main machine assembly and perform various functions presently to be set forth. The said output shafts all operate at the same. speed but in several directions 1. e. as indicated in Figure. '1 the shafts 52 and 53 both rotate counter-clockwise while the shaft 54 rotates clockwise. The shaft 52 serves to drive only the spike heading mechanism and the electrical switch 2 2- and its action will be described in detail below. The shafts 53 and 54, provide power for the function of raising, gripping, severing, drawing and ejecting the products and their actions together with their associated mechanical elements, will presently be described in detail.

We have provided, upon the base beams l8 and ll, 2. pair of upwardly extending supporting brackets 55 and upon these we mount a pair of pillow blocks 56 which are aligned to journal a transversely disposed lifter shaft 51. As viewed in Figure 8, shaft 51 will be seen to extend to the left beyond pillow block 56 and to this extension a crank 58 is attached. The free end of crank 58 pivotally engages the lower end of a linkage bar 59, the upper end of which is slotted to afford a lost-motion connection with a second crank 68. Crank 68 is secured to shaft 54 and at each rotation thereof imparts to shaft 51 a peculiar motion consisting of a rapid clockwise rotation, a rapid counter-clockwise return and a relatively long dwell which dwell occurs as crank 60 travels freely in the slot of linkage bar 59. A pair of depending arms 6| are secured to the central portion of shaft 51 and to the lower free end of arms 6| is pivotally secured the forward end of a conveyor supporting platform 62. Platform 62 has its rearward end pivoted to the lower free ends of a pair of equalizer bars 63 whose upper ends are in turn pivotally secured to upright corner beams 14 of the machine frame. Extending vertically from the forward end of conveyor supporting platform 62 and angularly braced thereupon there is provided a short length of roller conveyor 64 whose double flanged rollers 65 are adapted and aligned to receive the approaching blanks 38 as each is delivered by feed conveyor 26. An adjustable stop 66 is attached to one of the supporting brackets 55 and is positioned to bring the advancing bar 38 to a stop upon rollers 65. It will be apparent that as shaft 51 is rotated clockwise (as observed in Figure '1) the conveyor rolls 65 and the supported bar 30 will be swung to the left and raised in an arcuate path towards the next station within the machine.

To provide means for receiving and momentarily holding bar 30 as it is delivered from rollers 65, as described above a pair of electro-magnets 61 are rigidly suspended from a bridging member 68, which is in turn supported upon the upper cross beams 13 of the machine frame. Magnets 61 are provided with spaced, downwardly disposed pole pieces 69 which contact the blank 30 at two spaced points near its mid portion and thus the blank is held securely and in balanced horizontal position. energized by suitable contactors within sequencing switch 22 and they operate to. hold blank 30 while rolls 65 are quickly retracted and while a pair of working clamps referred to generally by the reference numeral 18 secure said blank.

Clamps 18 constitute means for holding blank 38 from this stage of the process until all opera-N tions are completed and a pair of finished spikes are delivered. Clamps 10 are basically constituted of a pair of clamp beams 18 which are freely journaled at their opposite ends upon transverse shafts 53 and 54 and which each bear a complement of parts now to be described. As both sets of clamps are alike except for the direction of their operation, the mechanism of but one set will here be described. Referring now to Figures 12 and 13 it will be clear that clamp beam 10 is an integral beam-like member and that it is freely journaled upon and supported by shafts 53 and 54. Anti-friction bushings 1| permit unrestrained rotation of both shafts and beam 10. is also free to slidev axially along both shafts. Suitably contoured cam wedges 12 are provided upon the inner face of beam 18' and are adapted to be engaged by complementary cam wedges 13 which are secured to cam discs 14. Cam discs 14 are keyed to shafts 53, and 54, respectively, and are located at the exact center of the complete machine.

Upon rotation of shafts 53 and 54 the wedges 12 and 13 react to move beam 18' outwardly from the center of the machine. Cam wedges 15, shaped similarly to cam wedges 12, are secured to opposite outer faces of beam 10' as shown. Return cam discs Hi4 and 16 are affixed to shafts 53 and 54, respectively, outwardly of the beams 18 and bear upon their inner faces cam wedges 11 which are complementary to wedges 15. Wedges 15 and 11 co-act, upon rotation of shafts 53 and 54 to return beam 18' toward the center of the machine. Thus it will be apparent that once upon each rotation of shafts 53 and 54 the two clamp beams 18' of the machine will move away from each other, i. e. outwardly from the center of the machine, and will return toward each other. The speed and distance of their travel may be regulated by the configuration of the mutually operating cam wedges 12-13 and 15-11.

Slideably attached to beam 18' and in depending relation thereto we provide a pair of clamp blocks and 8|. The clamping action of blocks 80 and 8| is initiated by the rotation of shafts 53 and 54 in the following manner. The cam discs 14, which are secured to shafts 53 and 54, each are provided with a toggle operating pin 82 which is located eccentrically upon said discs and extends on both sides thereof in a direction parallel to shafts 53 and 54. The location of pin 82 is clearly shown in Figures 9, 10 and 11. Each of the clamp beams 10' carry clamping mechanisms which must be operated and we therefore make pins 82 of sufficient length that they may always reach beams 10 whether said beams are closely or widely spaced from each other.

To the overhanging end portions 83 of beams 18 there is pivotally secured a toggle operating yoke 84 which is best seen in Figure 14. Pivot bolt 85 provides a fixed point for the rotation of yoke 84, the opposite end of which is pivoted to a toggle link 86 by a pin 81. The opposite end of toggle link 86 is secured to clamp block 88 by a pivot pin 88. When the entire toggle assembly Magnets 61 are cycliclyv is arranged as shown in solid lines in Figure 14 the pin 81 is raised above the center of pin 88, the upper edge of link 86 is brought to rest against a stop surface 89 and the block 80 is moved to the extreme left limit of its travel where it co-acts with mating clamp block 8! to secure blank 30 in place. The operation of the present toggle clamping assembly will be seen to make full use of the advantages accruing from the employment of such over-centering devices. When toggle operating yoke 84 is depressed, allowing pin 81 to assume the position indicated in broken lines, clamp blocks 80 and 8I will be retracted from their clamping position. Power to move operating yoke 84 is supplied by toggle operating pin 82 described above. As shaft 54 rotates, in the direction of the arrow in Figure 14, pin 82 is caused to contact the upper inside surface 8 3 of yoke 84 and to urge it upwardly thus raising toggle pin 81 and moving clamp 80 to a closed position. The relative length of inside surface 84' provides an index of the length of time the clamp means will secure the blank 39. As shaft 54 rotates further to the right pin 82 leaves upper surface 8 2 and presses downwardly upon lower surface 84 at which time toggle pin 81 is depressed and clamps 89 and 8| are opened. The length and contours of surfaces 84' and 84 are calculated to cause clamping to endure long enough and releasing to occur quickly enough to suit the other features of the routine of operation being performed.

To more efficiently secure work blank 39 the clamp blocks 80 and 8! are both made in different manners. Block 8| is a rigid member which has a groove 90 formed in its forwardly disposed surface to receive blank 30. Groove 90 is slightly wider than blank 30 but is not so deep as to completely receive it. Thus a slight portion of blank 30 protrudes to be pressed by block 80. Block 80 is provided with a spring biased face member 91 which is urged outwardly by spring 92. An adjusting block 93 provides means for varying the compression of spring 92 and thus of the ultimate gripping force of the entire assembly.

Each of the clamp blocks 89 and 8| are so constructed that they embrace opposite ends of blank 30 over a substantial portion of the latters length and they are so formed that they mutually constitute a forging die which determines the final shape of the underside of the head 42 and of the upset portion 42 of the finished prodnot of the machine.

To provide positive means for ejecting the blank 30 from the groove 98 upon the opening of clamp blocks 80 and SI there is provided a spring biased knock-out assembly referred to generally by the numeral 95. A plate member 98 is slideably mounted upon the outer face of clamp beam 10' and is free to move upon bolts 91 which are embraced by a slot 98. A tension spring 99 biases plate 96 toward the center of the clamping area. Tension adjustment of spring 99 is possible by changing the position of a spring clip I upon bolts IOI. A pusher bar I02 is secured to plate 96, is disposed adjacent to the clamp block 8| and is capable of expelling the bar 30 under the urging of spring 99. A retracting extension I03 is formed upon the rearward end of plate 96. Cam I04 is contoured to engage the inner surface of extension I03 during a major portion of the machines operating cycle and thus to hold pusher bar I02 retracted, but it is provided with a sharp declivity which permits almost instantaneous action of the entire knock-out assembly at the proper point in the operating cycle.

Attention is now directed to Figures 10 and 11 for a consideration of the severing mechanism of the present invention. As was noted above a bridging member 68 is provided at the center of the work area in our machine to support a magnet 61. We prefer to utilize this member also to support our cutting assembly. Upon the underside of member 68, in an area not occupied by magnet 81, we provide a pair of shear guide blocks I05'whioh afford support for a pair of sliding shear blocks I06 and I91 which confront each other from opposite sides of the location of blank 39. One of a pair of shearing dies I08 is carried by each of the blocks I06 and I01 and these dies are contoured to form upon the blank 30, the tapered cleft portions 43 and as shown in Figure l. There are also provided upon blocks I08 and I91, respectively, a lower restraining bar I09 and an upper restraining bar I01 which mutually embrace the lower and upper sides respectively of the blank 30 to resist deformation thereof during the action of dies Hi8. Shear blocks I09 and It? with their attached shearing dies and restraining bars are caused to advance to and retract from the work blank 30 by the action of the peripheral cam surfaces of cams 14, mentioned above, upon suitable cam connecting rods I09. Wrist pins IIfi afford required flexibility in the linkage between blocks I06 and I91 and connecting rods I99 and removable bearing caps I II facilitate assembly and repair of the shearing mechanism.

For considerat on of the forging hammer elements of the present invention attention is directed to Figures 7 and 10. W e utilize the base beams Ill and II and the upper longitudinal beams I5 of our machine frame to ri idly secure the lower and upper ends respectively of a pair of hammer pivot rods H9 and 12!. Suitable angle brackets secure the lower ends of the rods while the upper ends are held in blocks I29. Surrounding rods I20 and I'll and freely journaled. thereupon by anti-frictic-n bearings I29 are elongated sleeves I25. Securely welded to each of the sleeves is an upper or die supporting arm I 26 and a lower or linkage pivot arm I21. A stiffening web I28 is interposed between arms I29 and I21, is welded to both, and adds materially to the rigidity of complete hammer arms units. Upon the outer free end of each of the arms I26 a die holder I29 is secured and it is adapted to receive a die block I39 which formed to suit the operation at hand.

To cause both of the die supporting arms I29 to act simultaneously we provide a common drive for both and both are therefore connected to the drive ass nibly by suitable draw links I3! each of which has an outward free end pivoted to a pivot arm I21 of a respective hammer assembly. The inner ends of links I35 are pivotally connected to a cross head I32 which is slideably restrained upon a raised slide rail I33. A suitable beam and plate structure I34 supports slide rail I33 above cross beams of the machine frame. A master drive link I35 has its one end pivoted to cross head I32 and its opposite end pivoted to the lower end of a pitman lever I39. The fixed end of pitman I36 is pivoted to the machine frame by a pivot pin I31 and its intermediate point has pivotal connection with one end of a connecting link I38 through pivot pin I39. Mo-

tion is imparted to the entire hammer assembly by a crank I40 which is formed in power shaft 52 mentioned above and which has one end of connecting link I38 journaled upon its crank pin MI. The several links I3I, I35, I36 and I38 have their respective pivots arranged in such manner that they co -act to move both die supporting arms I26 inwardly toward work blank 30 in a comparatively rapid motion during the first portion of their travel and to move more slowly but with much greater force during the final part of their travel. This arrangement will be more clear upon consideration of Figures 16 and 17 of the drawing wherein the motions of the several parts are illustrated in various positions. In Figure 17 it will be apparent that as cross head I32 moves to the left from position A to B to C the angular relation between the centerline of link I3I and the line of travel of cross head I32 becomes less acute and more nearly linear. This places the several parts in position for most efficient transmission of the greatest mechanical effort. Figure 16 illustrates the advantage of the leverage action taking place in the vicinity of crank I40 on shaft 52. As the crank I40 is rotated in the direction of the arrow and as it travels through the upper arcuate portion of its path at about the position indicated in broken lines the leftward linear component of its speed is considerable and the motion of pivot MI and link I38 is therefore proportionally rapid. As crank pin I4I approaches the position shown in solid lines a line passing through pivot pins I39 and MI and shaft 52 approaches a straight condition and constant torque applied to shaft 521s thereby converted into a lateral motion of pin I39 which motion decreases in magnitude but increases in intensity as this straight line condition is reached. Since this most forceful increment of motion in the drive linkage occurs as the hammer arms I26 bring dies I 30 into action upon the work blank 30, considerable advantage will be seen to accrue from the arrangement of the present device.

It will be observed that the structural mem bers 68, I and I26 are all disposed about the working area of the machine in such manner that scale or other foreign matter which may drop from the blanks 30 can in no way interfere with any of the moving parts of our device.

In operation the machine of the present invention will carry out the several steps of the spike forging process in an entirely automatic manner. When the supply hopper, mentioned earlier, is filled with suitably cut square bars of I steel and the motor 32 is energized to operate walking beam conveyor 3I, the machine is in condition to function and the main drive motor I8 may be started to initiate the following cycle of automatically sequenced operations.

As blanks 30 move in lateral procession along conveyor 3| and the leading blank of the group is brought to rest against stop 33 the solenoid 34 will be energized by switch 22 to actuate linkage 35 and pusher 36 and to advance said leading blank into position within heating coils 38, 39 and 40. Energization of solenoid 31 by switch 22 will return pusher 35 thus allowing another bar 30 to move against stop 33. The next subsequent stroke of pusher 36 will cause a new blank 30 to advance and eject the preceding heated blank from the heating coils and onto feed conveyor 26. As the heated blank comes the rest upon rolls ,65 and against stop 66 the rotation of shaft 54 will furnish power via crank 60, bar '59, shaft 51 and arms 6| to swing conveyor 64 upwardly into the work area of the machine where magnets 61, energized momentarily through switch 22, will attract and hold blank 30. Conveyor 64 will next be retracted to its lower position and further rotation of shafts 53 and 54 will cause cam discs '14 to rotate and bring pins s2 to bear upon closing surfaces 84' of clamp operating yokes 84. The raising of yokes 84 will act through toggle links 86 to advance clamp blocks 60 and SI to securely grip blank 36 and at this time magnets 6'! will be deenergized. During the time that the clamp blocks and 8| have been moving toward their clamping position the rotation of shaft 52 has been causing crank I40 to move levers I38, I35 and I35 to the left, or outwardly of the machine, and to thus draw cross head I32 back and to apply tension upon draw links I3I. The attendant swinging of pivot arms I21 causes sleeves I25 to rotate and to bring die supporting arms I26 inwardly toward the opposite exposed ends of blank 30. Die blocks I30 upon the free ends of arms I26 are now forcibly pressed against clamp blocks 80 and ill to mutually effect the heading and upsetting operation upon the ends of the heated blank 30 and thus to simultaneously form the two heads 42 and the upset shank portion 42 as shown in Figure 3.

Upon completion of the heading operation die blocks I30 are swung outwardly of the machine and continued rotation of shafts 53 and 54 rotate cams '14 to energize the severing mechanism for forming the points of the spikes. As cams l4 rotate they force the shear blocks I06 and I 01 toward each other from opposite sides of blank 30 and partially sever it, forming therein the clefts 43 and 43 of Figure 4 and leaving only the relatively thin web 43 between their advancing faces. As cam discs I4 further rotate and begin to retract shear blocks I05 and ill! the cam wedges 12 carried upon discs 14 commence to engage cam wedges 13 which are secured to the inner faces of clamp beams 10' and to force both of the beams 10' away from each other along the shafts 53 and 54. Since clamps 80 and BI still retain their grip upon blank 3!! and since a set of clamps are rigidly carried by each of the beams 10' it will be understood that the motion imparted by cam wedges I2 and 13 results in a drawing operation in the unsevered web 43 which drawing breaks the web and completely separates the two spikes from each other.

Further rotation of disc 14 causes pin 82 to engage the lower surfaces 84 of yokes 84 and to break the toggle by depressing pivot 81 and thus to release the clamps 80 and 8| and. return them out of the work area of the machine. The two spikes are now each frictionally held within the grooves of their respective dies BI and it remains for the retracting cams I04 to be turned by shaft 53 to the position where they will cease their restraint upon the knock-out assemblies 95. When this occurs the extension I03 of plates 96 ride free of the cams I04 and springs 99 are free to quickly draw plates 96 and their attached pusher bars I 02 toward the right where bars I02 strike sharply against the finished spikes to expel them from die blocks 8!. Continued rotation of shafts 53 and 54 brings return cam wedges 'I'I into co-action with cam wedges 15 upon the outer faces of beams I0 and causes the latter to return toward the center of the machine where they may begin a repetition of their operating cycle.

The several steps of the complete cycle of operation thus far described obviously need not all occur as independently timed actions but are timed to overlap each other in a manner best calculated to result in the greatest overall efliciency of the machine and the process of the invention. By referring to Figure 15 of the draw ing one may see a graphic plotting of the relative time cycles required for the completion of the various motions. The abscissae of the graph are arranged in increments of degrees of rotation a fixed reference point upon the shafts 52. The zero condition is taken to exist when the shaft 52 is in the position illustrated in Figure 7, i. e. with the centers of shaft 52, the crank pin MI and the pivot pin I39 lying in a straight line. At this time the heading die blocks l3 are in their innermost position and are about to move outwardly, severing dies I05 and Hi! are about midway in their closing cycle, clamps 8D and ti are closed and cam wedges l2 and 13 yet have about 20 to travel before they engage. The ordinates of the graph are arranged in increments of distance traveled. These increments are not drawn to scale but rather show the proportional movement occurring in the several elements. The kinds of lines representing the motions of the several elements will be clear in the key accompanying Figure 15.

It should now be apparent that the machine and the process of our invention accomplish the objects initially set forth. Doubling of the production rate of the machine is achieved with an attendant economy in the size and strength of machine parts required. The heating of work blanks is accomplished in an efficient and economical manner by the use of induction heating coils 38, 39 and 4G. The reduction in scale which results from this method of heating permits more trouble-free operation by excluding excessive foreign material from the working parts of the machine. The shearing and forging action performed by our severing dies I08 and the drawing action performed by our clamps 80 and 8! combine to produce an extremely efficient and novel pointing assembly and method. The driving shafts 52, 53 and 54 and the various operating cams and cranks l2, l3, I4, 15, l! and M0, of our machine all operate in positive synchronism and are driven from a common source of power, motor l8, and thus are prevented from becoming misadjusted in any manner. Their operation is at all times positive, accurate and unified. The design and arrangement of the moving parts of our machine is such that any scale or foreign debris which may adhere to the stock blanks being fed thereto is allowed to fall free of the machine and can in no way incapacitate moving parts.

An important aspect of our invention is the heating of the stock material only at the locations where forming or working of the material will take place in the produtcion of the article. This arrangement is particularly advantageous in that it effects definite economies in the heating of the stock and in the reduction of scale loss, and in that it facilitates the operation of the clamping means of the heading and severing mechanism. As to the latter feature, it should be noted that the stock is clamped at a cold portion or portions which makes the tight gripping of the stock possible.

In the embodiment of the invention shown in Figures 18, 19 and 20, the stock is fed from a suitable source (a coil, for example) through the heating station 225 and through the heading and severing machine in a continuous step-by-step manner. At each pause in the movement of the stock a localized portion of the stock is heated by the induction heating coil 225, and it will be observed that the distance between the center of the heating coil and the center of the pointing and severing mechanism 208 is substantially equal to the distance between the pointing and severing mechanism and the heading or upsetting station. Thus, each spot or zone of heating of the stock serves both for facilitating the forming of the pointed end of a spike or the like and the forming of the head of the next succeeding spike or the like. The advantage of having a cold center portion of each spike is retained.

More specifically, the apparatus of Figures l8-20 comprises clamping means 300, 30!, carrying arms 205, and the severing tools 298, clamping dies 28%] carried by the slides 21!), and a head ing die 230' carried by the arm 229. The machine incorporating these various elements may be similar to the machine described above for it will be clear that with the parts opened as in Figure 18 the stock 238 may be advanced longitudinally to the position shown in the figure. Now the clamps 300, 38! and the dies 280 may be closed and the forging die 230 applied to form the head of the spike, all as shown in Figure 19. The next step is the closing of the cut-off dies 208 and the pullin away of the dies 28!] in the direction shown by the arrow in Figure 20 to sever the formed spike from the stock. During all these clamping and forming operations the stock is heated locally by the coil 225 so that the duty cycle of the heating means will be quite high. Immediately upon opening of the parts the stock can be advanced another spike length. If desired, we can employ other means, as electric resistance heating, for example, in place of the induction heating coil 225.

While we have limited the above specification to a detailed showing of the construction and operation of assemblies and machines for making railroad spikes it should be understood that the principles of the invention are equally applicable in the manufacture of headed nails and bolts and similar articles. The specifically illustrated and described embodiments of our invention therefore should be considered as illustrative only as obviously many changes may be mad 2 therein without departing from the spirit or scope of the invention. Reference should therefore be had to the appended claims in determining the scope of the invention.

What we claim is:

1. The method of producing spikes or the like each having an upset end which consists of heating a length of stock only at both end and at the center portion thereof, upsetting the heated ends of said stock length, and severing said length of stock at said center portion to provide a pair of headed spikes or the like.

2. The method of producing spikes or the like each having an upset head and a pointed end which consists of heating a length of stock only at both ends and at its center portion, upsetting the ends of said stock length, reducin the crosssectional area of said stock length at said centrally heated location, and thereafter pulling the two opposite end portions of said stock length apart to provide two spikes or the like each having a headed end and a pointed end.

3. The method of producing spikes or the like each having a headed end which consists of applying induction heating only to th two end portions and to the center portion of a stock length, thereafter simultaneously upsetting both ends of said stock length, and dividing said stock length at the centrally heated portion to provide two separate headed spikes or the like.

4. The method of producing spikes or the like which consists of applying induction heating only to the two end portions and to the center portion of a length of stock, simultaneously upsetting both ends of said stock length, reducing the crosssectional area of said centrally heated portion of said stock length, and thereafter pulling said stock length apart with the line of severance cor:- responding with said heated and reduced center portion to provide a pair of spikes or the like each having an upset head and a pointed end.

5. The method of producing spikes or the like each having an upset head which consists of heating only the end portions and the center portion of a length of stock, gripping said stock length at points intermediate said center portion and each end thereof, upsetting the ends of said stock length while the length is so gripped and thereafter pulling said grip portions apart with the line of severance coinciding with said centrally heated portion to provide a pair of spikes or the like each having an upset head.

6. The method of claim including the further step of swaging the centrally heated portion of said stock length preparatory to said pulling apart operation whereby said spikes or the like are provided with tapering pointed ends.

'7. In apparatus for producing spikes or the like the combination of three axially spaced induction heating coils to heat the end portions and the center portion of a length of stock, means to grip said stock length at points intermediate the centrally heated portion thereof and the heated end portions thereof, means to upset the ends of said stock length, and means to move said gripping means away from each other whereby said stock length will be pulled apart at said centrally heated portion.

8. In apparatus for producing spikes or the like each having an upset head the combination of means to feed predetermined and uniform lengths of stock in step-by-step progression and axially along a predetermined path, means adjacent said path to heat said stock lengths only at their end portions and at their center portions upon said stock pieces reaching a predetermined advanced position along said path, and means at the end of said path to simultaneously upset both ends of each succeeding stock length and to thereafter sever each succeeding stock length at the centrally heated portions thereof thus producing two complete spikes or the like from each length of stock.

9. In apparatus for producing spikes or the like the combination of means to feed successive lengths of stock in step-by-step axial progression, three induction heating coils mounted to encompass the end portions and the center portion of each succeeding length of stock as the same reaches a predetermined station alon its path of travel, and means spaced further along the path of travel of said stock lengths to upset the ends of said lengths and to sever said lengths at said centrally heated portions to produce two headed spikes or the like from each length of stock.

10. In apparatus for producing spikes or the like from an elongated blank heated at its end and center portions the combination of means to elevate said blank from a lower horizontal position to an upper horizontal position, means to grip said blank at its cooler portions intermediateits center and end portions when in said upper position, means to upset the ends of said blank while the blank is so gripped to form spike heads, and means to swage the centrally heated portion of said blank and to move said gripping means apart whereby said blank is severed to produce two spikes each having a headed end and a pointed end.

11. In apparatus for producing spikes or the like the combination of means to elevate an elongated blank heated at its end and center portions from a lower horizontal position to an upper horizontal position, an electromagnet having spaced pole pieces to engage said blank at its cooler portions to retain said blank in upper position upon retraction of said elevating means, means to grip the opposite end portions of said blank when in upper position, a pair of swaging dies for upsetting the ends of said blank while the blank is so gripped, and means to swage the centrally heated portion of said blank and to move said gripping means apart whereby said blank is formed and severed into two spikes each having an upset head and a pointed end.

12. In apparatus of the character described a pair of spaced parallel shafts coupled for simultaneous driven rotation, a pair-of spaced parallel struts mounted on said shafts andslideable axially along said shafts for movement toward and away from each other, cam means on said shafts for moving said struts toward and away from each other, and clamping means on said struts operative upon rotation of said shafts to clamp the opposite ends of an elongated work blank, the arrangements being such that said cam means is operative to move said struts apart while said clamping means grips the opposite ends of said blank.

13. Apparatus according to claim 12 further including swaging means to upset the ends of said blank while the same is secured in said clamps, and timing means to actuate said swaging means before said cam means is operative to move said struts apart.

14. In apparatus of the character described the combination of a crank shaft and two cam shafts mounted for rotation about spaced parallel axes, power means to rotate said shafts in unison, means to feed an elongated blank into a position substantially between and parellel with said cam shafts, a pair of struts spanning said cam shafts and slideable thereon axially of said shafts, clamping means on said struts for gripping opposite ends of said blank upon predetermined rotation of said cam shafts, swaging means coupled with said crank shaft to upset the ends of said blank while the same is held in said clamping means, swaging means operated by said cam shafts to flatten the center portion of said blank while the blank is held in said clamping means, and cam means on said cam shafts to move said sturts apart after actuation of said first and second mentioned swagin means.

15. Apparatus according to claim 14 further including means operative upon continued rotation of said cam shafts to open said clamping means following actuation of said means to move said struts apart and to thereafter move said struts to their initial adjacent starting positions.

16. Apparatus according to claim 15 further including automatic means to elevate a horizontally disposed blank into position between said opened clamping means when said struts are in their initial adjacent positions.

17. In apparatus of the character described the combination of a frame, a pair of spaced parallel shafts journaled on said frame, a saddle mounted on said frame and extending transversely above said shafts, a pair of spaced parallel struts mounted on said shafts in spanning relation therewith and slideable axially along said shafts for movement toward and away from each other, 10

said saddle being disposed intermediate and above said struts, means on said struts operative upon rotation of said shafts to clamp the end portions of an elongated blank, cam means on said shafts cooperating with cam following means on said struts to move said struts toward and away from each other upon continued rotation of said shafts, swage blocks slideably mounted on the underside of said saddle for movement toward and away from each other to reduce the thickness of a blank held in said clamping means, and cam means on said shafts coupled with said swage blocks to move said swage blocks toward and away from each other.

18. Apparatus accordin to claim 17 further 16 including means operative synchronously with said shafts to upset the ends of said blank while the same is held in said clamping means.

IRWIN ROPP. WILBERT S. BLACKSTONE.

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

UNITED STATES PATENTS Number Name Date 396,014 Thomson Jan. 8, 1889 483,424 Coffin Sept. 27, 1892 1,341,626 Kobert May 25, 1920 1,341,808 La Potterie June 1, 1920 1,344,961 Remington June 29, 1920 1,417,806 La Potterie May 30, 1922 1,755,323 Herron Apr. 22, 1930 1,867,936 Benedetto July 19, 1932 1,873,619 Mojonnier Aug. 23, 1932 1,998,363 Frost Apr. 16, 1935 2,195,775 Gaspar Apr. 2, 1940 2,275,763 Howard Mar. 10, 1942

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