US 1874158 A
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Description (OCR text may contain errors)
Aug. 3Q, 1932. A. 1 BAusMAN ET AL 1,874,158
FORGING MACHINE ATTORNEYS.
FORGING MACHINE 7)( ATTORNEYS.'
Au@ 30 1932-v A. 1 BAUSMAN ET AL 1,874,158
FORGING MACHINE Filed July 14, 1927 11 Sheena-Shea#I 3 ATTORNEYS.
lAUg- 30, 1932 A, L. BAusMAN ET AL 1,874,158
FORGING MACHINE Filed July 114. 1927 l1 Sheets-Sheet 4 INVENTR.
ug.' 30, 1932- A. l.. BAUSMAN ET AL 11 Sheets-Sheet 5 FORGING MACHINE Filed July 14. 1927 77.24,@ ATTORNEYS.
Allg. 30, 1932 u A. 1 BAusMAN ET AL 1,874,158
FORGING MACHINE Filed July 14. 1927 'll Sheets-Sheet 6 INI/ENTOR.
M BY 3 z &7,
Aug. 30, 1932. A, BAUSMAN ET AL 1,874,158
FORGING MACHINE .Filed July 14. 1927 11 Sheets-Sheet 7 fllzflll( IN VEN TOR.
www W ATTORNEYS.
Aug. 30, 1932.
A, L. BAUSMAN ETAL FORGING .MACHINE Filed July 14. 1927 11 sheets-sheet 8 A. L. BAUSMANv ET AL v FORGING MACHINE yFiled July 14, 1927 11 Sheets-Sheet 9 INVENTOR.
BY 7 7M ATTORNEYS.
Allg 30, 1932. A. L. BAUSMAN ET Al. 1,874,158
FORGING MACHINE Filed July 14, 1927 1l ShBtS-Sheb 10 @fg @ff A TTORN E YS.
Aug. 30, 1932. l A. L. BAUSMAN ET AL 1,874,153
FORGING MACHINE Filed July 14. 1927 11 Sheets-Sheet ll 2li I INVENTOR.
Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE ALONZO LINTON BAUSMAN, F SPRINGFIELD, AND EDWARD D. RAPISARDA, OF Y AGAwAM, MASSACHUSETTS, ASSIGNORS TO NATIONAL EQUIPMENT COMPANY, 0F `4-r SPRINGFIELD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS FOBGING y Application led July 14,
This invention relates to an automatic forging machine, of the class wherein articles may be successively heated and forged and the forged articles ejected.
The machine of this invention, while capable of other uses, is especially suitable for upsetting work, as for example, for forming heads on the blanks or stock fed into the machine. It will be disclosed, by way of illustrative example, as adapted to form cap Screws,-the upper end of a cylindrical blank of metal being first electrically heated and thenupset and shaped between cooperating dies to form the cap screw head.
i The general object of the invention-is to provide an improved machine for doing work of thea-beve described, or of an analogous character, with precision and at a rate high enough to meet practical production requirey ments and in an otherwise commercially satisfactory manner.
The invention also has for an object the provision of various features, capable of use independently or in conjunction, which are f directed to making the machine as nearly as possible fool-proof in operation. In particular, the machine, which involves electric heating means and a press for forging the heated articles, is sovarranged that thepress cannot be tripped to forge the articles unless and until the same have been Yheated to proper forging temperature. The control of the tripping of the press is made dependent on the operation of the electric heating means.
, Another feature is in the provision of means for automatically stopping the machine in thek event thata blank of more than the required length is fed into the machine or in the event that a blank, even if of proper length, is improperly positioned in its die, whereby damage to the machine, due to acts of carelessness in the feeding of blanks, is avoided. A further feature consists 1n provisions effective to stop the machine 1n case a forged article is not ejected from its die at the proper time. A still further feature lies in an arrangement for guarding against the possibility of the press being tripped and caused to strike articles which, while initially properly heated for forging,l have cooled below MACHINE 1927. Serial No. 205,815.
forging temperature by yreason of the stopping of the machine.
The invention also has for an object to provide an improved turret, having article holding dies, for carrying the articles successively into position for heating, forging and ejection and to provide improved means for intermit tently moving the same step by step and for locking it against movement while at rest.
Another object of the invention relates to the electric heat-ing means and especially to an improved construction and arrangement of those parts of the heating circuit which serve to couple the article to be heated to the latter, while the turret, or other intermittently operable carrier, is at rest.
fOther objects of the invention relate to improved provisions in connection with the forging dies,-especially to means for stripping the forged pieces therefrom and preventing them from sticking to the dies after the forging operation and to improved means for coolingV such dies after each forging operation.
A further object relates-to the provision of improved means for ejecting the forged articles, characterized by its ability to impart a quick sharp blow to dislodge the articles from and throw them out of their dies.
These and many other objects, which require for their understanding a consideration of considerable detail, will appear from the following description and will be pointed out in the appended claims.
The invention will be disclosed with reference to the one illustrative embodiment of it in the accompanying drawings, in'which Fig. 1 is a side elevational view of a machine embodying the invention,-the electrodes and associated clamping jaws together with their operating connections having been removed to avoid confusion and to clearly show the relationship between the turret and the press;
Fig. 2 is a sectional plan View, taken on the line 2 2 of Fig. 1 and drawn to a larger scale, showing the turret, its actuating mechanism. and the relationship between the turret and the electrodes, clamping aws and associated parts;
Fig. 3 is a fragmentary view, with parts in Y section, showing a detail of the turret operating mechanism;
Fig. 4 is a fragmentary elevational'view, taken .from Vthe opposite side; of the machine v from Fig. 1 and drawn to a larger scale,
showing the main driving mechanism, .its
controlling means andthe relationship loetween the latter vand the nism l. v Y Fig. 5 is a fragmentary view,partly in sece `safety' stopl mechation, showing the construction of the operate ing pawl for the turret and the manner in which'it engages in thepockets of the turret.;
Figo is a fragmentary plan view, with parts :broken away, of theturretpoperatmg pawl and Athe locking and unlocking "device therefor; -v f n V isa fragmentary elevational view taken lon the vline 7-7 of Fig. .6 showingthe operating `inea-.ns for the pawlY unlocking -device" r f L Fig. 8 isa frontelevationall view of the lower part ofthe machine,-the electrodes Yand clamping jaws having been removed for thesake of clearness andto, avoidne'edless confusion of parts ;V
"l Fig. i9 is laY sectional elevational view taken ion lthe Vline '9-'9 'ofF ig. 2v and showing the electrodes 'and jawsaiidl associated. mechal i nism;
f.' Fig...10 is a Vfragmentary elevational view v Fig.V 11 isa `fragmentary. plan View taken onrthe line ill-11 `of Fig. y9
i Y Fig. 12 isfa cross sectional view takenY on thel line 12-'12-of Fig. 11;
Fig. 17'is a Figs. 181and 1.9 Aare Y .tional views'of the upper .part of the machine icov vvin which the electric. heating equipment may f be .duplicatedmto provideffor two-stage Aheating of'thework .il .Y v
frontandlside elevashowing the reciprocable'ram ofV the press, Vthe upper dies and the stripper devices therefor Y 1' Fig. 19a is a sectional plan view. taken on V'the'.:line1 9a-V-119ca'of Fig. '18
,.Fig-s20 is abottom plan view of one. of the upper dies;
Fig.; 21 r is a fragmentaryV sectional view sho-wing'an upper and a lowerdie in thefrela-A tive positions which they occupy at the in- Y 'the iin@ as fesY of Fig. v27;
stant of completion of the forging ,operation Fig. 22 is .a longitudinal sectional view illustrative of the clutch of the press;
Fig. 23 is a cross sectional view taken on the 'line 23-23 of Fig. 22;. Y
Figs. 24 and 25 are fragmentary views, takenrsimilarly to Fig.V 23 but drawn to a larger: scale "and showing the clutch tripping device in its yinactive position `and in` its cocked position, respectively;V Y
Fig. 26v is a sectional View taken on the line 2(5-26Y of Fig. 24;
l Fig. 2'( is a-sectgional elevational view taken Von the line 27-27 of Fig. 2;
f lFig. 28 isa crosssectionalf viewtaken. on
Figs. 29l.and 30 fare fragmentary 'feleva- Y tional views, vtaken from the right hand Iend of Fig. 27 but drawn to a larger scale and .showing the cam for veffecting the trippingof the vclutch of the press in the respective positions vwhich it `occupies at the Ystart and. end, A
respectively, of the tripping interval;
Fig; 30a is a fragmentary elevational view showing the detail of the cliitchy elements shown in Fig. 27; V Y
Fig. 31 is a cross'sectional view takenonfthe line 31 of Fig. 2f; v
Fig. 32 is a view taken from the'right'hand end-of'Fig-r31; n Fig. 33 is a'sectionalview taken on the line 33-33 of 'Fig-32; v Fig. "34 is a sectionalelevationalj view taken 'on the line 34.-34 of Fig. 2; and
Y Fig.35 is a view takenon the line 35"-35 of Fig.;34. y y
The :machine shown in the drawings, while vcapalc'rle of other and various uses, willbe disclosed with reference to merely one'of its specific. uses, viz., the forming of -cap screws, such as shown at s in Fig. l5, from cylindrical blanks b. The blanks o are fedV by hand, or inV any other suitable manner, to dies el, carried by a turret T, (Figs. 1 and 2) which' is turned intermittently in step by step fashion. 'The dies `are preferably arranged in .pairs so that two blanks maybe treated simultaneously in each of -the'several stages of operations which ensue while the turret is atV rest. VAs shown,lthere are siX pairs of dies, eachpair of which successively comes to rest in sixpositions, during each revolution of' the turret.
-ln F ig; 15 the turret is shown diagrammatically in developed form and the six positions are designated Ito VI inclusive. VThesesame designations appear in Fig. 2 but the general work performed will be more clearly under- ;s'too'd from Fig. 15. "The blanks may be fed -to the dies when they occupy positions I orH,
' usually the latter.' Position III is provided Vto enable the use of a preliminary stage of heating, when necessary or desired. When the preliminary stage of heating is not used, blanks may be fed at this position also. vThe Vals final and often the only stage of heating is performed when the dies come to rest in position IV. In this position, the upper ends of both blanks are simultaneously and electrically heated. Two electrodes e, connected to the terminals of a suitable transformer as will appear, descend into Contact with the upper ends of the two blanks. At the same time the two blanks are electrically connected together at a lower level which is just above dies cl, by being clamped between a pair of copper jaws j, whereby the upper ends of the two blanks are included in series in the electric heatinfr circuit. Current is then supplied to the transformer and the blanks are heated to the desired degree. The blanks, having been suitably heated, are then ad* vanced by the next step of movement of the turret into position V. rThe dies (l, containing the heated blanks, are brought in under a pair of dies d carried by the vertically reciprocable ram o (Fig. l) of a well known type of press, the frame of which is designat'edV I). This press includes mechanism which when tripped, causes the ram to make one complete reciprocat-ion and then stop. Thereby the pair of dies d are moved rapidly downward from their upper and inactive position into engagement with the heated ends of the blanks in the dies al, whereby such ends are upset and forged between the mating dies to form the finished heads h of the cap screws. This forging operation, having been performed, the ram r returns to its upper position and dwells there until the press is again tripped. As the ram rises, the turret advances another step into position VI, in which the forged pieces are ejected,-this operation being performed by vertically reciprocable ejectors 7c.
The machine, in general, includes the following distinct mechanisms, viz., mechanism for actuating the turret in a step by step manner; mechanism for locking the turret against rotation while at rest and subsequently unlocking it; an optional and auxiliary mechanism for locking the turret while at rest and intended also for thefpurpose of resisting the vertically upward strains imposed on it when the dies d are stripped from the forged cap screw heads; the electrodes e and clamping aws nechanism for moving these electrodes into and out of contact with the. blanks and at the same time moving the jaws into and out of clamping relation with the blanks; mechanism for opening and closing the electrical heating circuit; th press P; m chanism for controlling the tripping of the press; the forging means comprising dies d; mechanism for stripping the heads of the forged pieces from dies d', and mechanism for actuating the ejectors lc. These several mechanisms function automatically in proper timed relation under the control, directly or indirectly, of a comm-on driving means. In addition, there are a number of important safeguards which are essential to insure proper operation of the machine and make it as nearly fool proof as possible. For example, means are provided for automatically stopping the machine in the event that a blank b projects more than a. certain distance above its die d, either because the blank is too long or because it is not properly seated in its die. Means are also provided to automatically stop the machine on failure of the ej ectors to completely eject the finished work. Another safety feature consists of mechanisms to prevent tripping of the press in the event of either of two conditions, viz., in the event that the blanks are not heated to the desired degree either from failure of current or because of poor contact between the blanks and electrodes or copper jaws and in the event that the machine is stopped for any reason so thatblanks, which were initially heated properly, have by the lapse of time become too cool to forge.
T tc turret The turret is mounted for rotation about a vertical axis and its lower face (Fig. 9) rests upon, and is turnable upon, a circular upper part of a bracket 34, which in turn rests upon and is secured to the vertically adjustable table 35 of the press as shown in Figs. `1 and 8. Said circular face is chamfcred, as shown in Fig. 9, and the turret has an interiorly bevelled, depending rim to engage the chamfered part,-the arrangement preventing the entrance of dust and dirt between the cooperating bearing surfaces of the turret and bracket 34:. The dies d consist of hardened cylindrical blocks which are set into the upper face of the turret, each pair being held in place by a single screw 3G, as shown in Fig. 2. The dies of each pair are equally spaced and the six pairs of dies are equally spaced and arranged in a circular series. Each die includes and has set into it, a hardened hollow cylindrical bushing 37 (Fig. 9) having a head and an extension of less diameter depending therefrom. The hole through the bushing is of the proper size to receive a blank b. Most of the wear on the die comes at its central portion wherefore such portion,-the bushing 87,-is made removable so that the replacement of only a small part of the die is necessary in the event of injury or wear.
The several bushings open at their lower ends into a common annular groove 38 formed in the bottom face of the turret. Siidable in the lower part of the opening in each bushing is a hardened pin 39, having at its lower end a head which is adapted to slide at times ron the upper face of bracket (Fig. 3S) and at other times upon a trackway l() (Fig. 9) fixed to said face. The'trackway and its purpose are best illustrated in Fig. l5, wherein the .arcuate trackway has beenfs'hown diagrammaticallyas straightened out and Vin developed form. As there shown, the trackway Vstarts at the. level of the upper face of bracket 34 at stati-on I and extends upwardly on an incline, reaching its highest level just before it reachesastation Il, and continues at such level -through stations HI and IV, and between stations IV and V drops abruptly to the level of the upper faceof brackets 34. Each time the turret moves, a pair of pins 39 ,Y are caused to ride up the inclined partY of the Atrackw'ay, whereby they are forced upwardly in'their bushings to a predetermined level, and thereafter this set of pins is held at such level until the heating operation has been *completed As the turret swings to carry a pair of heated blanks from heating to forging position, the pins are allowed to drop until their heads engage the upper face of bracket 34. The blanks b are supported upon the upper ends of pins 39 and the latter thereby serveV to properly locate the blanks 5 vertically in their dies cl. Each pin 39, when Vriding on trackway 40, holds its blank so that a considerable portion of the upper end thereof Y is projected above thetop face of its die.
ley shown. able clutch 45 an alined shaft 46. The clutch Thus, the requisite amount of the upper end of a blank b can beheated while heldout of contact with its Vdiethercby saving the die from the deleterious effects of the intenseheat to which it would otherwise be subjected. After the heating, the `pins 39 drop, as described, and the blanks dropdown in their dies until just enough ofeach blank projects above the die l to form the finished head h.
Cap screws V,of other lengths may be made by removing the pins 39 and replacing them withv similar pins of otherlengths. VTo enable this to be done, removable sections are provided in thetrackway, asbest shown in Fig. 15. At station II, two plugs 41 are secured to bracket 34 in a manner to permit convenient removal from below the bracket. The upper ends of these plugs normally function as parts of the trackway 40. When, however, pins 39 are tobe removed, the plugs V41 are removed and V two openings are left through which the two pins 39 at station Il may drop out. By turning the lturret step by step, the other Vpairs of pins drop out successively as they-come in line with the aforesaid openings. Y
' l The dri/ving mechanism `The main drive shaft is shown in Figs.A 2 and 4 at 42. It is rotatably supported in brackets 43 and 44 secured to the base portion of the press Yframe P and may be driven from any suitable sourceofpower by the pul- Shaft 42 drives through any suithasfbeen indicated vonly in conventional form -asitsparticular construction is not important. As best shown in Fig. 4, it is operated by a lever 47 through'the medium of a clutch collar 48.V When the lever is positioned as shown in Fig. 4, the clutch is in and shafts 46 and 42 Yare connected and when it is posi-V tioned as shown in Fig. l2, the clutch is out and said shafts are disconnected. Lever 47 is pivoted to bracket 44.', It is also connected to the bracket by a spring 49, which tends to Vswing the lever to the left` and throw outthe Lever 47 carries a roll 50 which is lower end of rod 53 is bent at right angles, as
at 55, to underlie the free end of latch 51. l/Vhen bell crank'52 is moved toward lever 47, rod 53 is elevated and the part 55 lifts latch 51 high enough to release it from roll 50, whereupon the spring 49 then moves lever 47 to throw out the clutch. The bell crank 52 may be operated manually in the ordinary waywhenever the attendant desires to stop the machine.` However, certain safety'provisions are made for automatically stopping the machine and these provisions effect the result by automatically actuating the vbellcrank4 52, as will 4later appear. 1
. Referring again to the Vdrive shaft 46, the
ylatter extends into a gearbox 56 (Figs. 4
and 8) and is rotatably supported therein as indicated. The cover, or top wall of the gear boX, is formed as part of a bearing bracket 57 which is fixed to a depending flange 35 of the table 35 of the press P (Figs. l and 4).
A second bearing bracket 58 is also Xed to said flange but at a point above the bracket V57 and these two brackets rotatably support a vertical shaft 59 (Fig. 8) the lower end of which enters gear boX 56 and carries a worm gear 60, which is driven by a worm 61V on shaft 46. Shaft 59 forms one section of aV lmaster or control shaft. A second section 62 (Figs. 2 and 4) is horizontally disposed and mounted to turn in bearings 63 provided on one sidewall Vof bracket 34. yThe forward endv of shaft 62 is connected by bevel gears 64 tothe upper end of shaft 59 and the'rear end of shaft 62 drives by bevel gears 65a third section 66 of t ie control shaft,-the latter section being located in back of the turret and-between bracket 34and the press Vand being rotatably supported in bearings 67 provided on bracket 34. The several sections 59, 62and 66 are geared together to turn at .equal speeds and vthey are the equivalent of a single masteror control shaft. .All of the various lme 3h2u1isn1s are driven or controlled, directly or indirectly, from this con- The turret operating mechanism The turret is intermittently moved step by stepgby a specially constructed oscillatin pawl 68 which moves successively into an out of a series of six notches 69 formed in the periphery of the turret T at equally spaced angular intervals. Pawl 68 is supported on the free end of a lever 7 0 and is pivotally connected thereto by a stud 7l which is fixed to lever 70. The stud 7l is recessed to receive a torsion spring 72, one end of which is fixed to the stud and the other to the pawl as best shown in Fig. 8. Spring 72 tends at all times to move pawl 68 toward the periphery of turret T. The lever 70, as best shown in Figs. 8. and 9, is mounted to turn on a centrally located hub 73 depending from the lower face of bracket 34, being held against axial movement thereon by a collar 7 4. Lever 70, at a point intermediate its ends, is connected by a link 75 (preferably adjustable as to length as indicated) to a crank 76 (Figs. 2 and 8), which is fixed to the upper end of a short vertical shaft 77. The latter is rotatably mounted in a bearing 78 formed as a part of the bearing bracket 58, heretofore described. The lower end of shaft 77 carries a pinion 8() (Figs. 2 and 8) which is adapted to be driven by an intermittent gear 81, fixed to the described section 59 of the control shaft. The arrangement is such that during one half revolution of the control shaft, the crank shaft 77 is turned one complete revolution and so that during the remaining half revolution of the control shaft, the crank shaft is held stationary in the position illustrated in Fig. That is, the pawl comes to rest in its advanced position and remains engaged in a notche69 of the turret during substantially ally of its interval of rest, being moved out of the notch at or about the end of said interval. The pawl is then drawn back to the position shown in Fig. 8 until it comes in line vwith another notch 69, whereupon spring 72 engages the pawl in the notch. The pawl then immediately starts forward to advance the turret by another step.
l The mechanism, as thus far described, of simple form but this ordinary type of mechanism is not sufficient in itself for present purposes. For one thing, the turret feeding mechanism must be capable of positioning the dies with close accuracy in relation to the several mechanisms which operate on the work contained in the dies and for another thing, it must repeatedly do this work with the same degree of accuracy even after the parts have become worn through long use. Also, it is desired to so construct the pawl that it may of itself serve as a. means for locking the turret against turning move-y ment during the interval of rest, although other means may be provided for this purpose as willjlater appear.
For the purpose of securing close accuracy in the throw of the pawl, which throw in the present case should be exactly sixty degrees, the connection between the link 75 and the pawl-carrying lever is made adjustable. The detail of this adjustment is shown in Fig. 3. The lever 7 0 is provided with a slot 82 in which a block 83 of square cross section is slidably received. To the lower end of this block the link is pivotally connected. The upper end of block 83 is threaded to receive a screw 84, which is mounted to turn in the lever 70 but is held against axial movement relatively thereto. By turning the screw 84, the block 83 may be moved in or out in its slot 82 and the throw of lever.70, and thus the throw of the pawl, may be varied in an obvious manner. Vith the turret held accurately in any one of its six positions of rest, crank 76 is turned to that one of its dead center positions in which the lever 70 and pawl 68 are retracted as in Fig. 8. Link 75 is then adjusted until pawl 68 accurately tits into the adjacent notch 69. rlhe crank 76 is then turned to its other dead center position, thereby advancing the turret, and screw 84 is adjusted until the throw of the pawl is exactly right to advance the turret into eX- actly the desired position.
In order to minimize wear, the end 85 (Fig. 5) of the pawl is hardened and the notches in which such end engages are formed in hardened blocks 86 which are set into re-. cesses n the periphery of the turret. Each such block is held in place by a screw 87. Viewing the pawl in plan, the center line 85 of part 85 is an arc struck from the center of stud 71 and thus from the center of oscillation of the pawl. The sides of the part 85 are likewise curved but not from the aforesaid center. These curved sides are made to converge inwardly, with respect to the center line referred to, and the sides of the openings 69 are correspondingly formed, converging inwardly. The end 85 of the pawl lits like a tapered plug into each socket 69. In this case, however, the center line of the socket and plug, instead of being straight, is curved from the pawls pivot point, whereby the plug end 85 may swing clear of its socket when withdrawn from the same. Due to this arrangement, when the sides of the pawl or the sides of the sockets wear, the pawl is simply thrust more deeply into its socket and thus compensation for such wear is effected without affecting the accuracy of positioning of the turret.
V(itV The mecwam'smV for locking and zmloccz'ag- .the turret c. Y
'With a pawl of. this type, means are required for withdrawingit from a socket prior to the start of itsreturn stroke; Such means comprises a short lever 88k (Figs. 5 to 8) with which the forward .part of the pawl moves into overlying relation when it nears the forward endY of its stroke. `Lever88 is provided with-an upstanding flange .89. Depending from the lower face of the pawl is a roll 90, which lies inthepath. of flange 89 and, when the lever 88 is swung outwardly from the tur- Y andthereafter the end face of part 85 eniss gages theperiphery Vof the turret and rides thereon until it reaches and enters `another socket 69. V I Y The lever 88 is fixed to the upper end of a short vertical shaft 91 (Figs. 6 and 7), rotatably mountedV in a hub` depending from a flange 92, which projects horizontally outward from bracket 34 beyondr its turret-supporting part. .The lower end of shaft 91 has liXed thereto a lever 93,I which is connected by a link 94 (preferably adjustable as to length as indicated) to the lower end of a lever 95.l VThe latter, at its .upper end is pivotcd to bracket 84 and intermediate its ends carries a roll to ride on the periphery of a cam 96, fixed to the section 62 of the control shaft and disposed between one of the Vbevel gears 64 and the adjacent bearing 63 (Figs. 2 and 4). A relatively strong spring 97 connects the lever 93 to bracket 34 and serves to hold the roll on lever 95 against cam 96 as well as to resist easy outward displacement ofthe lever 88, the latter actionV being necessary, as will shortly appear, because lever 88 is also made to perform'the vfunction of causingV the tapered pawl end 85 tobe thrust tightly'into its socket 69. The cam 96 is constructed so as to cause lever 88 to be swung outwardly away from the turret at almost the very end of the interval of rest thereof. This motion of lever4 88,.l which withdraws the pawl and .unlocks the turret, is very rapid as "will beseen from an inspection of the contour of the'cam. Following this motion, the
cam'neXt, causes the lever 88-to dwell in its outer position during theinitial part of the return stroke of pawl68, after which the cam allows lever 88 to be 'rapidly vmoved back by nsmfisi flangeis utilized-as astationary cam whichv is adapted to be engaged by roll 90 near-the end of the advance stroke of `pawl. 68, whereby to force the tapered end `thereof into close engagement in its socket 69; While the crank motion by which pawl 68 is recipro-V cated providesfora gradual Vacceleration and a gradual retardation of the pawl, the heavy turret acquires appreciable momentum, .tending to keep it in motion.l As ytherpawl is retarded near the end of its advance stroke, the turret tends to continue in motionk and there is a tendency for the pawlY end 85-to kbe moved outwardly in its socket. However, the cam ange 98 being held stationary by the strong spring 97, will force roll and thus the tapered end 85 inwardly; Thus, the tendency for the part 85 to move outwardly in its socket is overcome by the cam 98 and, not only this, but the part 85 is forced tightly into its. tapered socket in the turret, thereby accurately positioning the turret when yit comesto rest. The spring 97 enables the lever 88 to yield, if and when necessary, but it is so strong as not to yield until the end 85 Vis thrust tightly home. This spring .97 supplies a heavy tension to hold the pawl end85 in its socket and to securely lock the turret in position while at rest. It would not be feasible to provide enough tension inthe spring 72 for this purpose. "Thus, the latter can be made relatively light and yet function properly at all times, except at the end of the advance stroke of the pawl and at such time the necessary heavy tension is automatically brought into play and only at the time when it is needed.
'Auxiliary locking mechanism for the turret Tf necessary or desirable, yan .auxiliary mechanism may be provided for locking the turret in position while at rest Vand such mechanism may be used as analternative .to that above disclosed or as supplementary thereto or merely for the purpose of resisting the upward strains imposed upon the rvturret at the time when dies cl. move'upwardly at Vthe end of the forging operation. Experience,
thus far, has shown that the auxiliary locking radially in and out with respect to turret T. A series of holes 101, corresponding in number and angular location to the pawl receiving recesses 69, are provided in the periphery of turret T and these holes are located above the recesses 69. As shown, the holes 101 are frustoconical in shape, 4tapering inwardly, and the free end'of plunger 100 is correspondingly formed. The other end of the plunger has a pinrand slot connection with the upper end of a lever 102, which is pivotally mounted at a point intermediate its ends on a stud 103, fixed to the part 99 of bracket .34. The lower end of lever 102 carries a roll to ride in a path cam 104, which is fixed to section 66 of the control shaft. Cam 104 is so constructed as to move plunger 100 radially inward as soon as turret T comes to rest and to cause the plunger to dwell in such position during the interval necessary for the forging operation and to .retract the plunger shortly before the turret starts to move. The tapered end of the plunger enters the adjacent hole 101 and resists upward displacement of the turret. The plunger may also serve to lock the turret against rotation although the means heretofore described for the latter purpose are ordinarily sufficient. Plunger 100, however, is capable of use in place of said means or as supplementary thereto. For the vertical locking function the plunger would not have to closely fit all parts of the hole 101 as shown, and would merely have to closely overlie some substantially horizontal part of the turret.
The electrodes The electrodes e and associated clamping jaws are best shown in Figs. 9 to 13. Each of the electrodes e consists of a copper block mounted on the end of a copper shank 105. The latter, in practice, is arranged to be cooled and the water pipes 106 are indicative of means provided for this purpose. The shank 105 is clamped in a heavy copper lug 107 in which the conducting cable 108 is soldered. Each lug 107 is secured to one end of a lever 109 and the two levers 109 are pivotally supported intermediate their ends on a commonstud 110. The latter is mounted at its ends in a pair of brackets 111 secured to a pedestal 112, which rests upon and is secured to the flange 92 of bracket 34. The levers 109 are suitably insulated from stud 110, as by a fiber bushing 110 (Fig. 9) ,and the levers are also suitably insulated from each other and from brackets 111 as by fiber washers 111 (Fig. 10). The electrodes e are adapted to swing up and down about the pivot 110 and are illustrated in their vdown position. When thus positioned, the lower end face of each electrode e is exactly horizontal and squarely engages the upper end of a blank Z). The electrodes start to swing into the illustrated position just before the turret T comes to rest but do not actually contact with the blanks I) until the turret has come to rest. So also, the electrodes, at the end of the heating interval, break contact with the blanks b just before the turret starts to move but do not complete their upward movement until the turret gets in motion. In this way, as much as possible of the interval of rest of the turret is utilized for heating.
The clamping jaws j are mounted to slide radially in and out with respect to blanks b from opposite sides thereof. Each jaw j is wide enough so as to engage both blanks b of a pair, as clearly shown in Fig. 11, and the two blanks, being clamped between the two jaws, aie electrically connected together at points ust above the level of the upper faces of dies d. The current then flows down one electrode e, through the upper end of one blank b, across through jaws j to the other blank b and up through the upper portion of the latter to the other electrode e. The jaws j, which are preferably of copper, are preferably recessed, as shown to conform to the curvature of the blanks and assure close contact as well as contact of adequate area, with the blanks. Each jaw is mounted in a head 113, preferably in ak manner to permit convenient removal in order to facilitate repair and renewal, when necessary. Each head 113 has a slide 114 formed thereon which is received in ways 115 (Fig. 12). The sides of the latter are formed by adjustable side pieces 116 which not only permit adjustment to compensate for wear but enable the jaws to be accurately lined up with blanks The slide 114 is held in place in ways 115 by gibs 117. One set of ways 115 is formed in the flanged upper end of a post 118 (Fig. 9), which extends downwardly through a central hole in turret T and through the described centrally depending hollow hub 73 on bracket 34. The flanged upper end of post 118 rests on the upper face of the central recessed portions of turret T and .both the face of this flange and the periphery of the post have bearing engagement with turret T. Post 118 is held stationary by a set screw 119 and it functions as a central guiding bearing for turret T. The other set of ways are formed in the upper end of the described bracket 112.
Each of the jaw carrying heads 113 is moved in and out by a toggle mechanism, actuated by a vertically reciprocable plunger 120. One of these plungers extends centrally through post 118 and the other through bracket 112. The outer end of each head 113 is pivotally connected to one end of a link 121 and to the other end of the latter is pivotally connected a substantially vertical link 122 and a substantially horizontal link 123. The link 122 is pivotally connected to the upper end of plunger 120 and the link 123 is pivotally connected to a plunger 124, which is slidable in. an upstanding lug 125, formed that firm contact will be made with the work before the current is turned on. This avoids any arcing and consequent burning of the blanks and electrodes and jaws, which might otherwise occur but for the provisions described. It will also be apparent that the contacts 145 and 146 will be separated, and the heating current thereby out off, before the electrodes and jaws are disengaged from the work, which is important for the same reason as just above set forth.
The heating circuit The heating circuit is shown merely in diagrammatical form in Fig. 16. The two electrodes e, the two blanks 5, and the copper jaws y' are included in a series circuit with the secondary 152 of a heating transformer, the primary of which is designated 153. The primary 153, as shown, is connected to a 440 volt supply circuit, which is controlled by a magnetic switch 154. The latter is operated from a 110 volt circuit, which is controlled by the switch comprising the contacts 145 and 146, above described. The opening and closing of these contacts causes the opening and closing of switch 154.` A manually operable switch 155 may also be included in the 11() volt circuit to enable one f to shut off the Yheat independently of the automatic mechanism, when desired. The supply to the primary 153 is preferably through the intermediary of an auto transformer 156, by means of which the voltage supplied to the primary may be varied as desired. Included in the primary circuit is a solenoid 157, the piunger 158 of which is moved upwardly against the restraining action of a dash pot 159 and, when lifted, causes a contact 160 to move into engagement with a contact 161. Contacts 160 and 161 constitute a switch which controls a 110-volt supply circuit to a solenoid 162. A' manually operated switch 168 is preferably also included in the circuit to solenoid 162. The solenoid 162 has a function in controlling the tripping of the press, as will later appear. For the present, it will snllice to state that solenoid 162 cannot be energized until current fiows in the heating circuit and not then unless and until sufficient current flows to effect the desired deof heating of the blanks within the time interval available for the heating function. The laosition of the plunger 158 and the area of the leak 159 in the dashpot 159 determine the amount of current necessary to flow in solenoid 157 (and thus in the heating circuit) to cause a closing of the contacts 160 and 161.
T he press The press may be of any suitable type which will function when tripped, to cause the ram r to make one complete reciprocation, and then come to rest. As shown in Figs. 18
and 19, the ram 1 is, for convenience, made in upper and lower sections 164 and 165, which are interconnected by a screw 166 in such a manner that the sections 164 and 165 may be moved the one relatively to the other l to vary the vertical position of dies d and vadj ust them relatively to dies 4Z. The screw is threaded into the upper and vertically split part of the lower section 165 and its upper end is provided with a circular flanged head i' 167 adapted to turn and to slide laterally in a T-slot 168 formed in the lower part of section164. The screw may be turned from its upper end to effect the adjustment and, once the adjustment is made, it is preserved by al i check nut 169 and the clamping bolt 170. The section 165 has V-shaped edges (Fig. 19a) vwhich are slidably mounted yin correspondingly shaped grooves in a pair of gibs 171.
The latter are fixed to frame P by cap screws A 172 which pass through slotted holes inthe gibs, whereby the same may be adjusted laterally, as by screws 178, which thread into frame P and bear against the sides of the gibs. B means of this adjustment the dies d may e exactly alined with dies d, the head 167 of screw 166 sliding in T-slot 168 to permit the lateral adjustment of section 164 relatively to section 165. The latter is mounted for vertical sliding movement in a n pair of similar gibs 174 both of which are fixed to frame P but only one of which (the right hand one as viewed in Fig. 18) is adjustable. The adjustable gib 174 is mov- Vper section 164 of the ram and is received in a recess in such section as shown in Fig. 18.
The rear end of lever 17 6 is connected by a link 178 to a crank 179 (Fig. 1) on a crankshaft 180. The latter is rotatably supported in frame P and extends beyond one side of the latter, its outer end being supported in a bracket 181 secured to the frame. Disposed between said side and the bracket is the driving gear and clutch for the crankshaft. The driving gear, which is shown at 182 and which is driven by a pinion 188 from the main drive shaft 184 of the press, is free to turn on crankshaft 180.
The clutch is of a well known standard type and is best shown in Figs. 22 and 23. It includes a key 185 which is slidably mounted in a collar 186, fixed to the crankshaft 180 and which is adapted for movement in a direction parallel to the axis of the latter. A spring (conventionally indicated at 187) tends to move key 185 to the left (as viewed in Fig. 22) and, when permitted, to project the left hand end of the key into the path