US1755323A - Machine for forming hot metal - Google Patents

Description

April 22, 1930. A. 0. HERRON MACHINE FOR FORMING HOT METAL 2 Sheets-Sheet '1 Filed Sept. 14, 1928 Maw April 22, 1930. A. o. HERRON MACHINE FOR FORMING HOT METAL 2 Sheets-Sheet 2 Filed Sept. 14, 1928 Patented Apr. 22, 1930 UNITED STATES ALBERT O. HERRON, OF WATERB'URY, CONNECTICUT MACHINE FOR FORMING HOT METAL Application filed September 14, 1928.

This invention relates to an improvement inmachines for forming hot-metal of the type commonly referred to in some embodiments as headers, though my invention is ap plicable to other types of hot-metal forming machines, as will be hereinafter made apparent.

Heretofore in machines of the class to which my invention relates, the rod or wire stock operated upon has been heated before reaching the feed-rolls of the machine, with the result that if heated sufliciently to permit of a thorough forming operation when acted upon by the appropriate dies, it has been so softened as to be both markedly stretched and transversely deformed by the effort of the said feed-rolls in drawing the stock from a reel or other source of supply, and by the transverse gripping pressure of the said rolls.

The deformation above referred to, obviously would vary with the temperature of the stock (and hence its softness) and also with the resistance to be overcome by the feed-rolls in drawing the same from the source of supply. Thus, for example, if a 20-foot strip of preheated metal was to be pulled by the feed-rolls, its resistance to this pulling action would be greater than when, in the repeated actions of the machine, it has been reduced to, say a l-foot length.

It will be readily seen, therefore, that the factors of the temperature of the stock and its resistance to being fed are of such a variable nature as to be incapable, in a practical sense, of being foreseen and allowed for in setting the feed mechanism of the machine, which feed mechanism, to secure best results, must supply at each operation eX- actly the proper bulk of metal to the forming dies, no more and no less, within a very narrow tolerance range.

The object of this invention is to produce a simple and efficient machine for forming hot-metal, constructed with particular reference to securing a maximum forming action without reheating the stock.

lVith this object in view, my invention consists in a machine for forming hot-metal, characterized by having a heater interposed Serial No. 305,925.

between its feed-rolls or their equivalent, and its cut-off mechanism; whereby the stretching and deformation of the stock caused by the pull and pressure of the said feed-rolls is avoided.

My invention further consists in a machine for forming hot-metal, characterized as above, and having certain other details of construction and combinations of parts, as will be hereinafter described and particularly recited in the claims.

In the accompanying drawings:

Fig. 1 is a top or plan view of the hotmetal forming machine, embodying my invention;

Fig. 2 is abroken view in side elevation-of the feed-roll end of my improved machine;

Fig. 3 is an enlarged-scale broken sectional View taken on the line 33 of Fig. 1; and

Fig. 4 is a similar view taken on the line 44 of Fig. 1.

In the embodiment of my invention herein chosen for illustration, I employ a heading machine consisting of a rectangular frame 10 formed with a rectangular opening 11, the opposite side bars of which mount guideways 12 and 13, in which is adapted to reciprocate a ram 14 which is operated by a link 15 connected to it at one end by a pin 16, and at its opposite end attached in usual manner to a crank 17 offsetting from a driveshaft 18 carrying a fly-wheel 19 and having bearing at its respective opposite ends in the said frame 10.

The forward end of the ram 14 carries a forming-die 20 which co-acts with a complementary forming-die 21 mounted in the frame 10 to form various articles such as bolts, machine screws, tire-valve stems, etc. from short lengths 22 of rod or wire cut off from the end of a stock-strip 23 of random length.

Positioned in the frame 10 adjacent to the forming-die 21 therein, is a stationary cutoff die 24: located in the enlarged inner end of a bore 25 extending through the end portion of the said frame. The said bore 25 also receives a heat-insulating tube 26 which abuts at one end against the cut-off die 24: aforesaid, and is formed with an axial passage 27 registering with a corresponding passage 28 in the said cut-off die; through both of which the stock-strip 23 is fed by a driven feed-roll 29 in conjunction with an idler feed-roll 30 of usual form, both of which are carried by a bracket 31 offsetting from the adjacent end of the frame.

(lo-acting with the stationary cut-off die 24 aforesaid, is a cut-off slide 32 provided at its inner end With the usual spring clip 33 for gripping the stock as the projecting end of the same is cut off by the cut-off slide in its inward travel across the cut-off die 24. The said cut-0E slide is, as is usual in this type of machine, adapted to transfer the short lengths ofrod or wire 22 into alignment with a socket 34 in the forming-die 21 and therefore into alignment with a socket 35 in the aligned forming-die 20.

The outer end fthe cut-0d slide 32 mounts a roller 36 projecting into a cam-groove 37 formedin a plate-cam 3 8 reciprocating in a guide-bracket 39 offsetting from the side of \l the frame 10. The said cam-plate is periodically moved to cause the inclined reach 40 of its camgroove, to move the cut-01f slide 32 inward forthe purpose of cutting ofi the leffgth 22 from the stock-strip 23 and to transfer the same into alignment with the dies 20 21, by a link 41 connected to said slide by a pin 42 and having its opposite end connected to an eccentric crank-pin 43 extending outward from the face of a head 44 carried by the drive shaft 18.

"The plate-cam 38 above referred to, carries at left-hand end, as viewed in Fig. 1, a ca 'm arm 45having an inclined cam-surface 46 c o acting with a spherically-contoured roller 47 at the outer end of an oscillating electrodedever 48 mounted for oscillation upon a short shaft 49 bearing at one end in the frame 10, and at its opposite end in a supplemental bracket 50 offsetting from the bracket 31 above referred to. The said shaft 49 passes through three corresponding inwardly-extending arms 51 of the lever 48, each of which carrles at its inner end an upper electrode '52 of usual form and each of which, as shown, is formed in its under face with a longitudinal semi-circular groove 53 adapted to 'engage the upper surface of the rod or wire stock 23 and press the lower surface thereof against a series of grooved lower. 7 electrodes 54 which are lnsulated from the bracket 31 by a strip of. insulation 55 in the manner customarily employed in electric welding or heating devices.

A As will be noted from the drawings, the electric heating apparatus comprising the complementary movable electrodes 52 and stationary electrodes 54 is located between the feed-rolls 29 and 30.one one hand, and the cut-off die 24 and cut-off slide 32 on the other hand, so that portion of the rod or wire stock gripped by the said feed- rolls 29 and 30, as

well as that portion lying outward beyond the same, are not appreciably heated so as to be softened and consequently stretched by the feeding effort of the said rolls, nor deformed by the transverse gripping pressure thereof.

The driven feed-roll 29 and its complementary idler feed-roll 30 may be rotated step-by-step to effect the corresponding feeding of the stock-strip 23 by any of the wellknown mechanism commonly employed in .iachines of the type to which my invention relates. As shown herein, the feed-roll 29 is mounted at the forward end of a feed-shaft 56 having bearing in the bracket 31, and provided at its opposite end with a ratchet-wheel 57, the teeth of which are engaged by a pawl 58 pivoted to the upper end of an arm 59, which is oscillated by a link 60 pivotally connecte'd at its opposite end to a rocking-lever 61, The said lever 61 is mounted for rocking movement upon a stud 62 in the machine frame 10 and carries intermediate its ends a roller 63 held in engagement with the periphery of disc-cam 64 mounted upon the drive-shaft 18, by a helical spring 65.

For the purpose of ejecting the formed article from the forming-die 31, I employ, as is the usual practice, a so-called knockoutplunger 66 carried by an arm 67 offsetting from a bar 68 attached to ram 14, and projecting inward through the bottom of the socket 34 of the said forming-die 21.

In the operation of my improved machine, the feed-rolls are periodically actuated to project a predetermined length of'stock beyond the cut-off die 24, after which, in the timing of the machine, the plate-cam 38 is moved to effect the inward movement of the cut-ofi slide 32, the inner end of which coacts with cut-off die 24 to sever the extended portion of the stock and carry the same into alignment with the sockets 34 and 35 of the forming-dies 21 and 20, respectively. During this transferring movement, the section 22 of rod or wire just severed from the strip 23, is gripped by the yielding-finger 33 of the cut-off slide 32 in the usual manner of cut-off mechanisms.

After the section 22 of rod or wire has been positioned in line with the dies 20 and 21, as above described, the ram 14 moves forward and causes the die 20 to engage the said section of stock and force the same into the socket 34 of the stationary forming-die 21, thereby seating it therein, and headed or othewise formed.

Concurrently with the inward cut-off and transfer movement of the cut-off slide 32, the cam-surface 46 on the cam-arm 45 acts upon the roller 47 of the electrode-lever 48 and moves the electrodes 52 downward into engagement with the upper surface of the stock-strip 23, thereby completing the electrical circuit through the said stock between the said movable electrodes '52 and the stationary electrodes 54, which latter, as indicated, are fed with a low-potential high-ampere electric current through wires 69, with the effect of heating that portion of the stockstrip now gripped between the said electrodes.

It may be explained in this connection that shortly after the forming-die 20 has engaged the cut-off length of wire 22, the cut-off slide is retired out of the path of the said die.

The machine is so timed that before the feed- rolls 29 and 30 are again actuated to feed the stock-strip 23, the movable electrodes 52 will have been swung out of engagement with the said strip by the action of the cam-arm 45. In the retiring motion of the ram 14 the knockout-plunger 66 is brought into action in the usual way to eject the formed article from the die 21.

From the foregoing it will be seen that by means of my improved machine, not only is the stretching and transverse deformation of the stock-strip 23 avoided, but the heat in the heated portion of the said stock-strip is conserved by the insulating tube 26 and its closeness to the cut-oif mechanism, which comesinto action to present it to the action of the forming-dies very soon after it has been heated by the electrical current passing through it between the electrodes 52 and 54.

Furthermore, by means of my invention, I am enabled to heat the stock-strip to a sufficiently high temperature to efi'ect maximum forming at a single action of the dies 20 and 21 without affecting the accuracy of the feed which ordinarily, due to the deformation and stretching of the said strip, is a variable factor. This accuracy of feed, as has been hereinbefore pointed out, is essential to the accurate forming of various articles, as is well understood in the art.

It is obvious that even after the feed-mechanism has been set to feed a predetermined length of material, the bulk or volume of the material may have been changed by stretching or deformation, so that accuracy in the resultant formed article is more or less a matter of chance.

I claim:

1. In a hot-metal forming machine, the combination with the feed-mechanism and cut-off mechanism thereof; of an electric heater positioned to heat a portion of the stock extending between the said mechanisms and including two electrodes one of which is movable with respect to the other; and automatic means for periodically moving the said movable electrode into and out of engagement with the stock; whereby the said stock may be heated to a sufiiciently high temperature to permit maximum forming without subjecting it to stretching and deformation before being cut off.

2. In a hot-metal forming machine, the combination with the feed-mechanism including stock-gripping members, and the cut-off mechanism including stationary and movable members; of an electric heater including two electrodes one of which is movable with respect to the other and positioned to heat a portion of the stock extending between the said stock-gripping members of the feedmechanism, and the said stationary cut-off member of the cut-off mechanism; and automatic means for periodically moving the said movable electrode into and out of engagement with the stock; whereby the said stock may be heated to a sufficiently high temperature to permit maximum forming without subjecting it to stretching and deformation before being cut off.

In testimony whereof, I have signed this specification.

ALBERT O. HERRON.

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