US2202016A - Manufacture of metal articles - Google Patents

Description

May 28, 1940. c. A. MccuTcHEON 2,202,016

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May 28, 1940. c. A. McCUTCHEON MANUFACTURE OF METAL ARTICLES 4 Sheets-Sheet 2 J INVENTOR. 6%;10 WW A TTORNEYS.

Filed lay 23, 1938 May 1940- c. A. M =CUTCHEON 2,202,016

MANUFACTURE OF METAL ARTIGLES In: m 23. 1938 4 Sheets-Sheet s A TTORNEYS.

May 28, 1940. c. A. McCUTCHEON MANUFACTURE OF METAL ARTICLES Filed lay 25, 1938 4 Sheets-Sheet 4 INVENTOR} 'ae d- W/c 624% 6%,)? walk/$142211 I ATTORNEYS.

Patented May 28, 1940 PATENT OFFWE MANUFACTURE OF METAL ARTICLES Clyde A. McCutcheon, Coraopolis, Pa., assignor to Pittsburgh Forgings Company, a corporation of Delaware Application May 23, 1938, Serial No. 209,403

5 Claims.

My invention relates to the manufacture of metal articles, particularly to articles that are shaped from bars or straps of steel. The invention consists in method.

In Letters Patent of the United States, No. 2,015,194, granted on September 24, 1935, to one Max Ruping, a resilient rail fastener is illustrated and described, and in exemplary way I shall describe the present invention as it has been practised in the manufacture of such rail fastener.

In the accompanying drawings Fig. I is a diagrammatic view in plan of apparatus in the operation of which the invention is realized. Fig. II is a fragmentary view in side elevation of a heating furnace and bending machine included in the apparatus. Fig. III is a view to larger scale, showing partly in side elevation and partly in vertical section the cooperating dies of a forming press included in the apparatus;'the dies are in open, work-receiving position, and a blank is shown in the matrix of the lower die, ready for the upper die to close upon it. Fig. IV is a view in front elevation of the parts shown in Fig. III, with the blank omitted. Fig. V is a view comparable with Fig. III, showing the upper die in course of descent upon the lower, and illustrat-' ing the blank partly formed into the ultimate article. Fig. VI is a view comparable with Figs. III and V, showing the dies completely closed and the article completely formed. And Fig. VII is a View in side elevation of the finished article.-

The resilient rail fastener, which in this case is the product of my method, is illustrated in Fig. VII of the drawings. It consists in a bipartite body that includes a shank portion I and a head portion 2, integrally formed of a medially folded strap of spring steel. The two limbs of the strap extend from the fold in face-to-face contact, and together are shaped into the rail fastener illustrated. The body of metal at the fold is externally tapered, as at 3, to provide a blunt point at one end of the shank I, and at the opposite end of the shank the bipartite body of the article extends laterally (reversely curved in its extent) and provides the head 2. The head is in effect a cantilever leaf-spring extending from the shank E. For further details in the matters of structure, use, and advantages of this rail spike, reference may be made to the Ruping patent, above noted.

I shall now turn to a consideration of the method in which the invention centers. In Fig. I the reference numeral 4 is applied to a heating furnace in which straps S of steel, cut to proper length, are heated to a temperature at which they may be worked and shaped in the manner presently to be described. In this case the steel of which the straps are formed is a spring steel, including from .90 to 1.05 percent. carbon, and

the straps are heated to a working temperature of 1700 F., more or less.

removed (either automatically or manually) from the furnace, and positioned one by one upon the table 5 of a bending machine 50.

The table 5 is provided with a medial slot 6,

and upon the face of the table a pair of workshaping blocks 1, I and rolls 8, 8 are mounted, one block and one roll on each side of the slot 6, as shown in Fig. I. Beneath the table (Fig. II) an endless chain 9 is trained over sprocket wheels [0 and i100, and in known way an electric motor and driving connections (not shown) are provided for rotating the sprocket-wheels and driving the chain 9 in the direction of the arrows in Fig. II. The chain carries a plurality of dogs ll that are arranged at suitably spaced points in the peripheral extent of the chain, and in the operation of the machine these dogs, moving upward around the sprocket Wheel I00, enter the slot 6 in the table 5 and travel in left-to-right direction therein. As shown in Fig. II, the distal ends of the advancing dogs project above the surface of thetable 5, and as presently will appear, provide traveling abutments that cooperate with the blocks 1, I and rolls 8, 8 in shaping the Work.

on the table (Fig. I) and brought to position against the edges la, "la of the blocks; while the strap lies in such position one of the continuously traveling dogs II (the first dog to enter the slot 6 when the strap has been so positioned) moves into contact with the strap, and, while the opposite ends of the strap bear against stationary edges Ta, la, the advancing dog carries the medial body portion of the strap forward between the two convergent edges lb, "lb' of the blocks. As the center of the strap is thus carried inward be tween the blocks l, l, the opposite ends of the strap swing angularly from the edges la, la, and the body of the strap becomes V-shaped. In the continuous advance of the dogthe strap is carried, with the apex of the V in the lead, from the pass between the blocks l, 1 into and through the pass formed by and between the rolls 8, 8, with the consequence and. effect that the legs of the V are brought together, forming the strap into a narrow U-shaped blank B, as shown.

The heated straps'are 5 When the trailing end of the blank B emerges from the roll pass, the dog reaches the end of the horizontal course through which the chain 9 travels, and as the chain rounds the sprocketwheel ill in clockwise direction (Fig. II), the dog moves downward in circular course and is Withdrawn first from the folded end of the blank and then from the slot '5 in the table 5. The blank lies freely upon the surface of the table.

Before proceeding further, it is to be noted that the gauge-blocks i2, i2 are arranged at unequal intervals on opposite sides of the slot 6 in the table, to the end that one leg of the U-shaped blank shall be slightly longer than the other, as shown in Fig. I. The advantage of this refinement will presently appear.

At the delivery end of the table 5, two forming presses l3, B3 are arranged, and in these presses the U-shaped blanks B are formed into the article shown in Fig. VII. Ordinarily, one press only is operated, the other being held in readiness in case of a breakdown. In service the blanks B are removed (either mechanically or manually) from the table 5, and introduced one by one to the active forming press. In a single stroke of the press, each blank 13 is formed into a finished article (Fig. VII).

Upon leaving the forming dies of the press, the formed articles move down a slideway H30 to the surface of an endless conveyor i l, and on such conveyor are carried into an annealing or quenching furnace l5. Emerging from the annealing furnace, the articles are conveyed through a quenching bath 1%, and from the quenching bath the articles go to the usual draw furnace 59. If, as sometimes will be the case, the draw furnace is remote from the quenching bath, the articles are collected in a receptacle i! at the delivery end of the bath, and in such receptacle the articles are carried to and introduced to the remote draw furnace. If, on the other hand, available space permits the draw furnace 58 to be located adjacent to the discharge end of the quenching bath, the articles coming from the bath are conveyed immediately into the furnace.

It will be understood that the operation of the press l3 and the speed of the conveyor i 4 may be so regulated that the forged articles are delivered to quenching furnace 5 at temperature of from 1200 to 13% degrees F. the speeds of advance of the articles through each unit of the apparatus may be regulated so that the annealing, quenching, and drawing of the articles is accomplished in accordance with recognized good practice. Further detail in the matter of heat treatment is unnecessary to a full understanding of the invention.

Turning to a consideration of the structure and mode of operation of the dies in the forming presses I3, attention is directed to Figs. III to V1. Each press includes a female die and a male die. The female die consists in an anvil block l8 which is integrated with a base 20, and the male die consists in a block 59, held in assembly with a head 2i, by means of a plurality of vertical stemsin this case four stems 22. The female die assembly i8, is rigidly secured upon the bed of the press (not shown), while the male die assembly 59, 2| is carried by the vertically reciprocable cross-head of the press. I do not show the press structure proper, for the reason that there are many known makes of presses which may be used, and there is no radical departure from common practice in the manner in which I assemble the dies in the press.

When the cross-head of the press is at the upper end of its stroke, the dies are separated, as shown in Figs. III and IV; and, alternately, when the cross-head is at the lower end of its stroke, the dies are powerfully closed, as shown in Fig. VI.

Within the upper face of the die block 23 a matrix 23 is formed, and this matrix is adapted when the press closes to receive a male portion 22 carried by the die block i9, and to cooperate with such male die portion in shaping the folded end of a blank B into the shank portion 1, 3 of the rail fastener. (Note Figs. VI and VII.) The matrix 23 is continued downward from the upper horizontal face of the die block it between two vertical flanges 25 on the side of the die clock, and the body of the block between these flanges is contoured, providing a matrix portion 23a in the form of the head 2 of the rail fastener. And it will be noted that the outer edges" of the flanges 25 are parallel with the contoured Wall of suc'n matrix portion.

In accordance with the invention, I provide means that cooperate with the matrix portion 23a, while the folded end of a blank B is by the male die held captive in matrix 23, in forming the bipartite end of the blank into the c 'ved head of the rail fastener. Advantageously, such means consist in a roll 26, arranged between, and trunnioned in, the lower ends of a pair of lever arms 2']. The lever arms 2? are pivoted, on a common axis 28, to the body of the upper diecarrying block 2|, and a tension spring 29 is secured between such block and the upper end of each arm 21. The block 2i carries abutments, in this case in the form of rigid pins 2'58, for preventing the arms 2'! from swinging counterclockwise from the vertical position in which they appear, one behind the other, in Fig. HI, but it will be understood that, opposed by spring tension, the arms may swing in unison through a limited range in clockwise direction. On the base 20 of the lower die assembly two vertical cam-bars 30 are rigidly mounted, and on the axle 33 of the roll 26 at the lower ends of lcvcr arms 2'! two cam rollers 32 are mounted for free rotation. In the operation of the press, when the upper die assembly closes upon the lower, the rollers 32 (moving downward with the upper die assembly) engage and roll upon the inwardly curved edges 3! of the cam-bars with the consequence and effect that the descending lever arms 27 are swung clockwise and the roll 28 caused accurately to shape the bipartite end of a blank B to the contour of the matrix portion 23a. Before describing the operation in greater rictail, there is another feature of construction that should be described.

As already mentioned, the upper die block 99 is assembled with the supporting block 2 i, by means of four stems 22. These stems consist. in this case, in bolts whose threaded ends are rigidly sccured in the body of the block 2%; the four bolts xtend in parallelism downward from th supporting block 2| and carry heads [52a at their lower ends, and between the heads 22a and the body of block 2i, the die block E9 is vertically movable on the shanks of the bolts. A helical. compression spring 36 is mounted on the shank of each bolt or stem 22. These springs are effective between the blocks 25 and i9, and tend to maintain the block H5 in a position spaced from the bottom of block 2|, with the bottom of the block 19 bearing against the heads 6f the bolts 22. (Note Fig. III.) And it is'to be noted that the bodies of the blocks l9 and 2i are recessed, as at 35, to receive the opposite ends of the springs 34. By virtue of such structure, the block 2i may, as presently will appear, be closed tightly upon the block 19, with the springs 34 compressed and nested entirely within the pockets 35.

In the operation of the press, a heated blank B is removed from the table 5 (Fig. I), and, while the continuously reciprocated upper die assembly is at the top of its stroke, the blank is positioned in the matrix 23 of the lower die block. It is important to note that the U-shaped blank is placed in the matrix, with the longer leg of the U above the shorter, and in order to facilitate the accurate positioning of the blank in the matrix, I provide a fixed, though adjustable, stop 36. (Conveniently, the stop 36 is carried by the cam-bars 3%), as shown.) The blank B is positioned in the die block it with the longer leg of the U abutting against the stop 36. (Note Fig. III.) Presently, the continuously reciprocated upper die assembly descends, and in the course of such positive movement the following operations are effected:

1. The male die portion 24 of the die block it enters the matrix 23 and engages the folded end of the blank B. The downwardly moving die block i9 is arrested, with the folded end of the blank securely clamped, under the tension of springs 33, between the die blocks l8 and I9..

2. While the two limbs at the folded end of the blank are thus held against longitudinal displacement in the matrix 23, the spring-resisted descent of the block 2i and lever arms 21 continues unabated; the interval between the blocks l9 and 2! decreases, the rollers 32 at the lower ends of the lever arms 2?, thus carried downward, make contact with the upper ends of the vertical cam-rails 3Q; the compression of springs 34 increases; and the pressure on the clamped end of the blank is correspondingly increased,

3. The roll 28, carried downward by the descending lever arms 21 moves into contact with the paired limbs of the blank extending from the closed dies. As the movement of the descending parts continues without interruption, the otherwise free limbs of the blank are by the roll pressed downward and rolled, from a medial point outward, limb against limb, into the crookshaped matrix portion 23a. (Note Fig. V.) The cam edges 3! are so contoured that, as the rollers 32 move downward in contact therewith, the paired lever arms 2?, holding at first to a straight vertical course, swing clockwise and move the descending roll 26 through such path that the bipartite end of the blank is formed to the exact curvature of the matrix portion 23a. The desired crook-shaped head is thus formed in the article. (Note Fig. IV.)

4. As the roll 26 approaches the end of its blank-forming sweep, the springs 34 are completely compressed within the pockets 35 and the descending block 2! closes upon the die block l9. While the bipartite end of the formed crook is by the roll 25 secured upon the contoured surface of the die block 58, the supporting block 2! abuts upon the die block is and presses it downward with great pressure. That is to say, the die block 89 is forced downward from the position shown in Fig. V, in which it primarily serves to clamp the folded end of the blank upon the block l8, to the position shown in Fig. VI, in which the male die portion 24 cooperates with the matrix 23 in tightly closing the folded end of the blank and pressing it to its ultimate shape. that the die portion 24 and matrix 23 are so particularly fashioned (at 24b and 231)) that the desired slight taper 3 is provided at the pointed end of the shank.

5. Simultaneously with such powerful closing of the die block l9 upon the block l8, the crookshaped head of the formed article is engaged by a portion of the block 2i. That is, a rigid die portion 2| a depends from the body of the block 2!, and the lower end of this portion Zia is shaped to the curvature of the formed article, in the region between the shank portion I and the head portion 2. As the die block l9 enters its ultimate shank-forming position (Fig. VI), the

die portion Zia closes tightly upon the shaped blank, as shown, with the effect that not only is relative movement between the two limbs of the formed article prevented, but a set is given to the metal in the region of greatest curvature.

The advantage of forming one leg of the U shaped blank longer than the other will now be manifest. Comparing Figs. III and VI, it will be understood that, while the folded end of the blank is held against longitudinal displacement and the roller 25 is shaping the bipartite end of the blank against the contoured die block, the outer ends of the two limbs of the blank are free for relative longitudinal movement. Thus, dur-. ing the rolling of the bipartite end of the blank against the convex face of the die block it, relative movement between the outer ends of the limbs is effected. The greater length of the upper limb of the U makes compensation for the radial difference in curvature between the inner and outer limbs of the blank, so that in the finished article the outer ends of the two limbs lie flush, or substantially so, as shown in Figs. VI and VII. In refinement of the apparatus described, I provide means for laterally aligning the two limbs in the shank portion of the formed article, it being noted that the two flanges 25, 25 on the side of block l8 serve to insure alignment of the limbs in the crook-shaped head portion. Such means consist in a die plate 38 (Fig. IV) arranged in a slideway 39 in the body of the lower die block H3. The upper die block i9 carries a cam block 40 which, when die block I 9 is powerfully closed upon block 18, moves downward upon an inclined face 38a on the outer edge of die plate 38, and effects the movement of the die plate inward, pressing its inner edge forcefully against the folded body of metal within the matrix 23. In such manner the two limbs of the article are die-pressed into precise alignment.

In still further refinement of the apparatus described, I provide means for dislodging the formed article from the matrix in die block 18. Specifically, I provide an orifice 6| in the wall of the matrix, preferably in the contoured floor of the matrix and at the point where the convexity of the contour is greatest. (Note Figs. III to VI.) Fluid under pressure is supplied to this orifice, and preferably compressed air is the fluid used. In this case a tank 62 of compressed air is connected to the orifice, by means of a lead 63 and a passage 64 formed in the body of the die block. Advantageously, if not essentially, communication between the tank and the orifice remains open, and so long as the orifice BI is uncovered a jet of air plays into the open atmosphere.

When in service the upper die assembly of the machine descends and presses thebipartite end It will be noted of a blank into the matrix portion 23a, the orifice SE is closed by the body of the metal being worked. The flow of air from the orifice is thus interrupted, but it wili be understood that air at supply pressure is eifective upon the inner surface of the crook-shaped head of the formed article. When in due course the upper die assembly rises, this air pressure is eiiective to dislodge the formed article from the die l8, and the blast of air thus released blows the article longitudinally away from the die and directs it to the slideway 133 (Fig I), whence the article moves under gravity to the conveyor 54. It may additionally be men tioned that the streaming air, impinging upon and deflected by the body of the article leaving the die, serves to cleanse the matrix of scale.

In the operation of the apparatus above described the method of this invention is practised, and it will be understood that the invention is not limited to the manufacture of rail fasteners of the sort herein described.

In the foregoing specification the dies have been described as they operate in a vertically reciprocable press, but it will be understood that they may be embodied in a horizontally reciprocated press or bulldozer. And it goes without saying that other departures from the description may be made within the terms and intent of the appended clahns. And as an example of a variation contemplated, I mention that the limbs of the U-shaped blanks need not be spaced apart, as described; that is to say, the limbs may be tightly closed in surface-to-surface contact be fore the blanks are introduced to the dies of the forming press.

I claim as my invention:

1. herein described method which consists in folding a strap of steel into a U-shaped blank, clamping the blank at its folded end upon a contoured die block and rolling a crook in the opposite otherwise free end of the blank against the contoured face of the block, and, while the formed crook is secured between the rolling instrumentality and the die block, pressing the two limbs of the blank extending between the crook and the folded end into the form of a shank.

2. The herein described method which includes folding a strap of steel into a U-shaped blank, clamping the blank at its folded end upon a contoured die block and forming the opposite otherwise free end of the blank against the con toured face of the block, and, while the so formed end continues secured beneath the forming instrumentality and the die block, die-shaping the folded end of the blank.

3. The herein described method which includes folding a strap of steel into a U-shaped blank, with one limb of the U of greater length than the other, clamping the blank at its folded end upon a contoured die block and forming the opposite otherwise free end of the blank, limb against limb, against the contoured face of the block and with the shorter limb of the U positioned between the face of the block and the longer limb, and, while the so formed bipartite end of the blank is secured between the forming instrunientality and the die block, die-shaping the folded end of the blank.

4. The herein described method which includes forming metal into a U-shaped blank, with one leg of the U longer than the other, and, while admitting of relative longitudinal movement between the distal end portions of said legs, shaping the bipartite end of the blank into a crook and bringing the ends of the legs into juxtaposition at the tip of the crook, and, while securing the constituent portions of such bipartite crool: against relative movement, pressing the portions of the legs between said crook and the bend in the U into the form of a shank.

5. The herein described method which consists CLYDE A. MCCUTCHEON.

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