US1717513A

US1717513A - larcher

Info

Publication number: US1717513A
Authority: US
Publication date: 1929-06-18
Anticipated expiration: 1946-06-18

Description

June-18, 1929. A. J. LACHER 1,717,513

POCESS AND APPARATUS FOR FORGING CRANK SHAFTS June 18, 1929. A. J. LARCHER PROCESS AND APPARATUS FOR FORGING CRANK SHAFTS Filed May 31, 1927 8 Sheets-Sheet 2 E N AN S,

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Jurie 18, 1929. A. J. LARCHER 1,717,513

PROCESS AND APPARATUS FOR FORGING CRANK SHAFTS Filed May 31, 1927 8 Sheets-Sheet 3 j f W M @da MM y uw x June 18, 1923. A. J. LARCHER PROCESS AND APPARATUS FOR FORGING CRANK SHAFTS Filed May 31, 1927 8 Sheets-Sheet 5 J3 embr- June 18, 1929. A, J, LARCHER 1,717,513

ING CRANK sHAFTs Filed May 31, 1927 8 Sheets-Sheet 6 I( 4 @i llLLN (//l/ (Ny (//l V s@ m .f2/C, QW ffm-W2 June 18, l1929. A, 1, LARCHER 1,717,513

PROCESS AND APPARATUS FOR FORGING CRANK SHAFTS Filed May 51, 1927 8 Sheets-Sheet 7 June 18, 1929. l A. J. LARCHER 1,717,513

PROCESS AND APPARATUS FOR FORGING CRANK SHAFTS l y y l/ i;

Patented June 18, 11929.

UNITED STATES PATENT OFFICE.

ALBERT J. LARCHER, OF CHICAGO, ILLINOIS, ASSIGNOR TO WYMAN-GORDON COM- PANY, OF WORCES'IEIEL,V MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PROCESS AND' APPARATUS FOR FORGING CRANK SHAFTS.

Application filed May 31,

The invention relates to the die-forging cranlesliafts and seeks to provide an im proved method and aj'iparatus for manufacturing the same, and particularly multithrow crank-shafts having integral counterweights.

Crank-shafts for the multi-cylinder engines of automobiles and the like, are forged from a rolled steel bar, usually of uniform cross-section and having the grain or liber of the metal extending lengthwise of the bar. In order that the grain or fiber in the finished shaft shall extend axially of the pins and journals and lengthwise of the crank arms or cheeks, the heated bar of stock is subjected to offsetting or so-called edging dies, by which it is bent back and forth at a number of longitudinally spaced points to form the offsets or throws and roughly outline the crank arms, journals and pins of the shaft, and the blank thus formed is then die-forged to bring its parts substantially to the desired contour. The usual bending or offsetting operation tendsI to stretch and 'weaken the meta-l, and this is particularly the case in forging a crank-shaft having a large number of single throws, i.. e., one having journals on opposite sides of each throw, since in suoli a shaftt-he pins and journals are usually quite short. Furthermore, it is difficult to provide such a bent or offset blankwith `suitable ae cumulations of metal for forming integral counterbalancing offsets or other projections. Indeed, it is believed to be quite impractical to do so by methods heretofore in use in the manufacture of automobile engine shafts having journals on opposite sides of each throw andcounteii'balancing projections on each cheek or cran t arm. While some automobile engines are equipped with such shafts to avoid vibration at different speeds, the counterweights are usually bolted 4or otherwise fastened in position and this method of manufacture is unsatisfactory. The present invention provides an improved forging method and apparatus for theformation of crankshafts for automobiles and like multi-cylinH der engines and especially of shafts having the. u'iaximuni number of journals and integral. counterweights.

In accordance with the present invention. the metal of the bar of stock is accumulated 1927. Serial No. 195,406.

into protuberances or enlargements, one for each throw, and preferably by turning or rotating the bar and subjecting it to transyerse pressure between relatively reciprocating die members. The enlarged portions of the blank are then indented on opposite sides to partially divide the same transversely, and preferably by subjecting the blank to the action of forging dies having pairs of opposed, wedge-shaped die elements, to thereby allocate metal for pairs of adjacent crank arms or cheeks. The blank is then brought substantially to the desired contour by shaping dies. In this way, one or more throws of a crank-shaft can be formed by the application of the pressure of the forming dies to the blank in a direction transverseto the plane of the formed throws, and at the saine time, if desired, the arms or cheeks of the throws can be provided with integral counterbalancing projections.

The improvement is hereinafter further set forth. in detail, the apparatus employed is illustrated in its preferred forms in the accompanying drawings, and the invention is more particularly defined in the appended claims.

In the drawings:

Fig. l is a plan or face view of one of the die members having impressions for forming the blank from the bar of stock and for breaking down the blank and thereby roughly forming the journals and throws of an integral counterweighted, multi-throw crankshaft.

Figs. 2, 3 and 4, are longitudinal sections taken on the lines 2 2. SH3 and 4 4 respectively of Fig. l, and illustrating the impressions in both thel upper and lower dies.

Fig. 5 is an end view of the up per and lower dies.

Figs. 6 and 7 are cross-sections on the lines 6 6 and THT respectively of Fig. 1.

Fig. 8 is a plan or face view of one of the contour shaping dies.

Fig. 9 is a cross-section thereof on the line 9 of Fig. 8. y

Fig. 10 is a plan or face view of a die member in which the impressions for forming a. multi-throw crank-shaft are somewhat modified.

Figs. 11,12 and 13 are longitudinal sections taken on the lines 11-11, 12-12, and 13-13 'espeetively of Fig. 10, and illustrating both the upper and lower die members.

Fig. 14 'is an end view of the die members shown in Figs. 10, 11, 12 and l3.

Fig. 15 is a cross-section thereof taken on the line 15-15 of Fig. 10.

Fig. 16 is a longitudinal section, and Figs. 17. 18 and 19 are cross-sections, illust-rating the operation of the dies shown in Figs. to inclusive.

Fig. 2O is a plan view illustrating a modification of the initial impression or die cavity.

Fig. 21 is a longitudinal section on line 2i-21 of rig. 2e.

Fig. 22 is a cross-section on line 22-22 of Fig. 21.

Fig. 23 is a partial plan view and Fig. 24 is a section on line 24t-24 of Fig. 23, illustrating the operation of the die cavities shown in Figs. to 22 inclusive.

Fig. 25 is a plan view illust-rating a modilied form of die block.

Figs. 26, 27 and 28 are longitudinal sectiens taken on the lines 26-26, 27-27 and 28H28 respectively, of Fig. 25.

Figs. 29, 30 and 31 are cross-sections on the correspondingly numbered lines of Fig. 25.

Fig. 32 is a. plan view, and Fig. 33 is a cross-section illustrating the operation of the dies shown in Figs. 25 to 31 inclusive.

The die blocks or members are of the lusual type employed in steam hammers and presses and in which the upper die block is connected to the piston of the steam hammer and is thereby reciprocated to and from the lower die block. In the drawings, only the adjacent portions of the die blocks containing the cavity-forming impressions are shown. In the form shown in Figs. 1 to 7 inclusive, the upper and lower die blocks 10 and 10 are provided. with three impressions a, Z), and o, Which form three die cavities through which the blank is successively passed. Co-operating impressions in the upper and lower die blocks which form each of these cavities are counterparts. The impressions a have longitudinally spaced portions 1 of relatively small cross-section and intermediate recesses 2 of relatively large cross-section. rPhe contracted portions 1 and the enlarged recesses 2 are provided With gradually rounded surfaces Which are convex'and concave respectively, as most clearly shown in Fig. 2, and are oval in cross-section with rthe major axes of the oval sections lying in the plane of the parting line of the die members, as shown in Figs. 5, 6 and 7. ln the particular form shown, the central and end reduced .portions 1 which shape the corresponding journalforming portions of the blank are preferably somewhat longer than the other portions 1 Which shape the other journal-forming portions ofthe blank. The cavity a is also provided at its opposite ends With portions 3 and l for forming reduced and enlarged ends on the bar of stock, and with portions 5 forming a cavity into which the tongshold of the blank extends.

The impressions Z) are provided With portions 1, 2', 3, Il and 5, which are quite similar to the corresponding portions of the impressions a, except that the major axes of the oval cross-sections of the recesses 2 are vertically disposed instead of horizontally, as shown in Fig. 7, and these recesses are substantially rectangular in longitl'idinal section, as shown in Fig. 3, instead of oval. The impressions c are provided with opposed elements 6 for roughing out the journals of the crank-shaft, and with opposed portions or recesses 7 for outlining` the counterweighted throws. Each of these recesses is provided with a pair of opposed, wedge-shaped dieelements 8, one on each of the die members. These pairs of die-elements S are arranged in the central transverse portions of the recesses 7, and extend transversely from one side of each recess across the vertical plane of the longitudinal axis of the die cavity and merge into semi-circular recesses 9 (see Figs. 1 and 7), which roughly outline the crank pins.

For convenient, quick handling of the stock during the forging operation and in order that the ope ation may be completed with a single heating of each bar of stock, the im pressions, e, l5, and c are preferably formed in a single pair of die members. Preferably as shown, the impressions c and 7) are formed in the enter portions of the faces of 'the die members and which portions do not quite contact when the die members are engaged. The

impressions c are, as shown in Figs. 5, G, and

7, preferably formed in the central contacting portions of the faces of the die members.

lllhe rolled steel bar from which the crankshaft is forged is preferably of uniform crosssection that is larger than the cross-section of the reduced portions 1 of the impressions a, and is smaller than the cross-section of the recesses 2. It the stock is of square section. it is of sul'istantially the size indicated in dotted lilies in Figs. l and 2. The hvated 'oar o l* stock, having a tong-hold formed on one end, is first struck a number of blows While located between the die impressions c, the bar being rotated about its longitudinal axis after each blow and preferably through an angle of substantially degrees. In this way, the metal of the stock opposite the portions 1 is reduced in cross-section and the metal which is displaced by these portions is caused to flow into the enlarged portions or depressions 2. Thus, by the application of pressure of the die impressions a to the bar ol' stock transversely of its axis, longitudinally spaced portions of the bar are reduced in cross-section and the cross-section of the intermediate portions is increased to form a series of the enlargements of protuberances, the reduced portions preferably corresponding in number' to the journals oi' the finished crank-shaft, and the enlargements or protuberances corresponding in number to the throws. In this operation the metal is squeezed and compacted both in the reducedand enlarged portions of the die impressions and in such a manner that the grain or fiberoi the metal adjacent the axis and surface of the blank thus formed are respectively substantially parallel thereto. The blank thus formed is substantially a counterpart ot' these impressions although it may not quite fill their extreme horizontal dimensions, and it is substantially symmetrical with respect to a horizontal plane coinciding with the parting line ot' the. die members.

The blank is then transferred to the brealo ingr down7 impressions is .rotated about its axis through an angle of degrees and is struck a single blow while located in these impressions. As already noted, the impressions are provided with portions l', 2, 3', et and 5 which correspond to the portions l, 2, 3, t and 5 oit the impressions o, and en gage corresponding parts of the blank. By these die impressions the metal of the blank is compressed and the surfaces of the reduced portions are brought more nearly parallel to its axis, and the side faces and the peripheral portions et the protuberances or enlargements are brought more nearly at right angles and parallel respectively to 'the blank axis.

The blank is then rotated through an angle ot substantially 90 degrees and is struck a number of blows while located in the die impressions c. The portions 6 oit these die impressions, which engage the reduced portions, rough out the journals of the crankshaft and the opposed die elements 8 having wedgeshapedfaces partially divide or split each of the enlargements or protuberances of the blank to thereby allocate metal for pairs of adjacent counterweighted crank arms. ln the particular form shown, the die elements 8 also cooperate with the

portions

7 and 9 ot the die impressions c to rough out the counterweie'hted crank arms and pins of the throws'. It isnoted that in this dividing' or splitting operation, each protuberance of the blank is-iheld or locked between two of the reduced or journal-tformingportions G of the dies so that` the metal displaced by the die elements 8 is forced to flow transversely and compactly lills the portions 7 and 9ct the die cavity. When the die members are 1n engagement, the opposed wedge shaped edges ol the elements 8 are spacedv some distance apart so that they do not completely divide the portions ot the protuberances ot the blank engaged thereby, but the metal of the protuberances or enlargements of the blank is allocated and roughed out to form the crank pms and countervveighted cheeks of the throw by the application of pressure transversely to the plane of the formed throws and which plane is coincident with the partingl line ot the dies. TWhen operated upon by the die inipressions c, the metal of the blank substantially fills and becomes a counterpart of these die impressions, although, pra-iterably the stock and these impressionsA re so related that no excess metal is squeezed out of the impressions.

The blank is then submitted to the action of counterpart die impressions (l formed in two die blocks or members ll. and ll (see Figs. 8 and 9). As is clear from these figures, these impre. `iions are provided with portions tor bringing3 the journals, crank-pins, counterweighted crank arms and other parts of the forging substantially to the desired contour, i. e., the contour or shape that the parts should have before the tinal iinishingj or machiningoperation. These die in'ipressiens are necessarily designed to torce out a small amount of surplus metal alongl a flash line l2. In the die forging; operation the throws are preferably formed all. in a com mon plane. Then, after removing' the tin oi surplus metal in a suita-lilc flashing die, the crank lthrows are indexed or broughtI to proper position by any suitable means and preferably by means ot indexingl dies such as set forth in my prior Patent No. lASLGQG, dated January* i7, 1922. After the indeKingg1 or throw-positioning operation, the crank is subjected to the action of scttiira` dies which bring,` all oit its parts to proper form and position tor the final. machiningn operation.

lVith the improved method and apparatus, the entire forging, throw-indiniing or positioning and setting can be accomplished with al single heating oi" the origina-l bar ot stock. It noted that the die-torging operations, including the roughingi' out ot the cra/nk throws, are effected by the application et the pressure o'lI the dies in a direction transif'erse of the axis oit the blank and sulistantially at right anales to the plane ot the throws formed by the dies, and that the metal at the axial portion of the blank is maintained substaiu tially straight throughout. In other words, there is no bending of the axial portion of the blank in an offsetting or edging die, and consequently there is no stretching ot' the metal. Instead, the entire forging operation is a. compactiug' or squeezing;` o'tl the metal oi the stock. Notwithstanding the tact that there no bending' of the blank in an edging; die, as in prior practice, the rgrain ofthe metal. in the iinished forged crank-shaft is properly disposed axially ot the journals and pins and sulistantially lengthwise and parallel to the surfaces of the crank arms. The iinproved method and apparatus also provides for the manufacture of a crank-shaft in which the throws have integral forged counterweights, and it is believed that the pres- Cir fil

ent invention is the first to provide a satisfactory method and means 'for die-torging an integral crank-shaft having the maximum number of journals and integral counterweighted crank arms. Although the throws ofthe crank-shaft are preferably rouglied out and brought to the desired contour by torging all ofthe throws iii a common plane, and then positioning the termed throws, the method could be inodilied by forging the throws at least partially in position. But in any event, in accordance with the presentimproved method, the throws are roughed out and brought to the desired contour by the application ot the pressure of the torging dies iii a direction transverse to the plane or planes of the formed throws. llfl'iilo, set forth, the present method and apparatus are particularly designed and adapted tor the manufacture oie. coiinterweighted crankshatts, they are believed to be applicable to the formation ot pairs oit closely adjacent transverse arms or projections on other like orgings.

In the modiication'shown in Figs. 1t) to 15 inclusive, the impressions l) and the second forging step above d scribed are omitted and the impressions a', 0 and d are all loi'iiied in a single pair-o1' die block.; or niembers 13 and 13. The blank ttoriiiiiig and roughing out impressions ci and 0 are formed in the outer portions oi the faces of the die blocks that are spaced slightly apart when the die. blocks are engaged and the shaping 4die cavity CZ is formed in the central meeting portions of these faces. rllhe impressions e are substantially similar to the impressions (i of the die blocks and 10, and the inipressions c and d areA quite similar to the impressions c and d, the slight diilierences in lorin being clearly indicated in the drawings.

Figs. 16, 17, 18 and 19 are drawn on the samescale as Figs. 10 to 15 inclusive, and illustrate the operation ot the die cavities a', o and 0. The original bar of stock of uniform square section except for the tong-hold at one end, is indicated in broken lines in Figs. 16 and 17. and in4 Vlull lines these tigiires show the blank formed by the die 'impressions a, the blank in this form having, as described, portions 1 of reduced section and portions 2 ot enlarged section. 1n the impressions e, the enlargements ot the blank are partially divided and the journals 6a, counterweighteiil crank arms 7a, and pins 9a are roughed out and these parts are brought to proper contour. as shown in Fig. 19, by the impressions CZ. rlhen, atter removing the lin 12, the throws are indexed or brought into their' proper relative angular positions. Preferably the impressions in the die blocks 13 and 13 are so arranged that the blank is rotated through 180 degrees as it is passed from the impressions c, to the impressions d'.

instead, oit initially subjecting the bar et' stock to a bla-nk forming operation between dies having impressions (a and fr as described, it may be tirst subjected to breaking down7 or edging dies to 'torni the blank having alternately reduced and enlarged portions. Thus the die blocks 11 and 14.- (see Figs. 2O 21 and 252) which are designed to form the same crank-shaft as the dies 13 and 13', are similar to the latter dies in all respects except that the iii'ipressions ZJ- are substituted tor the impressions a. These impressions have large opposed cavities 15 and pairs oit opposed projecting transverse ribs 16 which are preferably pri'ivide'd with rounded edges that are concave `in transverse direction as shown in Fig. 22. In this case the bar ot stock, while containing the same amount of metal, is rectangular in section and it is subu jected to the operation ot the impressions e2 with its wide faces vertically disposed as indicated in broken lines iii Fig. 2Q. The pairs ot opposed transverse projections 1G of the die cavity will forni the portions 16a of reduced cross section. (see Figs. 23 and and the displaced metal and that in the remaining portions ol tliebar oi stock will form the enlargements 152 In this operation the metal contacts only with the central portions ot the walls o1" the die cavity. lt is noted that in this breaking down operation, the metal ot the stock is compacted and is not stretched and the axial portion ot the bar is not bent or oiiset. jitter this initial operation the blank is rotated about its axis through an angle of degrees and is then subjected to die impressions like the iinpressions c and Z oit' the die blocks 13 and 3, and is successively brought to the forms shown in Figs. 18 and 19.

The dies previously described are particulai-ly designed tor forming six-throw, sevenbearing crank-shafts having a counterweight on each cran1r arm. rlhe improved process and apparatus are also adapted for forging cranksliai'ts having uiicounterweighted singlel throws, or in which only some of the throws are counterweiglited. Thus the dies shown in Fi 25 to 31 inclusive are designed. to form an eight-throw, nine-beariiig shaft with counterwc-,ights on the two end and the two central crank arms. ln the drawings. only the portions of the dies toi' Forming the two central throws and the three throws on the one side of' the central throws are shown, but the parts for forming the throws on the other side of the central throws are of similar form.

The die blocks 17 and 1'7, like the dies 153 and 13 previously described, are provided with blank `forming, roughing out and tiii ishiiig die cavities a2, .2 and d2. Similarly, also, the impressions for forming the cavity a2 are provided with

portions

21 and 22 oli oval and of relatively small and large cross section respectively for shaping the correspending portions el? the blank. But the impressions in the upper and lower dies are not symmetrical counterparts and the portions or cavities 22 which receive and shape they enlargements or protuberances of the blank are not opposed in the upper and lower die blocks. instead they are alternated or staggered most clearly shown in Fig. 26, and the enlargements 22l of the blank (see Figs. 32 and 33), which are subsequently formed into the crank arms and pins, are similarly disposed and are eccentric with respect to the axis ot' the blank. Also, the upper die block is provided at each end with a narrow cavity Q3 and as the stock is rotated between the reciprocating die blocks, met-al is forced upwardly into these cavities and thereby allocated tor forming counterweights on the crank arms at the opposite ends of the shaft. lit is noted that, while quite narrow, the cavities 23 are ot such size (see Fig. 29) that the metal does not contact with and is not conlined by the edge walls thereof. The impression a2 is also provided in the lower die block with a central cavity 24 into which metal is toi-eed to provide an enlargement which is later formed into integral counterweights i'or thetwo central crank arms. A portion ot the blank as it is formed in the die cavity a2 is indicated in broken lines in Figs. 32 and 33, and the relative location of the parting line oit the die blocks indicated by the line fi2-a2 in Fig. 33.

Upon the transfer of the blank from the impression a2 to the impression c2, it is rotated about its axis through an angle of 90 degli-ies. Here as betore the reduced portions ot the blank are engaged by journal forming parts 6 and the enlargements of' the blank by portions or cavities 7 having oppositely disposed pairs of wedge-shaped elements 8', that partly divide or split the enlargements, and also having portions 9. The

parts

7', 8 and 9 serve in the manner previously described to rough out the crank arms and pins. But in the torm shown, only the throwforming cavities at the center' and ends of the impressions c2 are provided withV portions 25 for roughing out the counterweights for the two central and the tworend crank arms. A portion of the blank shaped by the impressions 02 is shown in full lines in Figs. 32 and 33 and the relative location of the parting line ot the dies is indicated by the [line i2-c2 in Fig. 33. It should also be noted that the portions 26 of the die blocks on opposite sides of the cavities 6 that form the central journal, engage and divide the enlargement. of the blank that is formed in the cavity 24 of the impressions a2, and so aid in roughing out or allocating metal for the counter-weights on the two central crank arms. The parts are finally brought to the desired contour in the die impressions d2.

Throughout the forging operations with the diiierent forms shown, the metal is compacted between opposed die elements, there is little or no `stretching of the ,tiber of the metal and no overlapping or folding of the grain, and the grain or fiber is properly disposed in the iinished forging. Other modiiications may be made and the details set iorth varied without departure Vtrom the scope of the appended claims.

I claim as my invention:

1. The method ot' making multi-throw crank-shafts which comprises forming a. plurality of enlargements on a rolled steel bar, then, while maintaining the axial portion of the bar substantially straight, breaking down the enlarged portions ol' the blank to allocate metal to Jform the throws, and then shaping the throws and journals substantially to the desired contour.

2. The method of making die-forged, multi-throw crank-shafts which comprises forming a substantially straight blank having longitudinal portions oll relatively large and small cross-section, then die-forging the blank to form the smaller portions into journals and the larger portions into throws by applying the pressure. of forming dies in a direction transverse to the plane or planes oit' the formed throws.

3. The method of niaking die-ttorged multi-throw crank-shafts having integral counter weights, which comprises tirst tormingy a substantially straight blank having longitudinally spaced portions oi enlarged cross-section, then, while maintaining the axial portion of the blank substantially st aight, breaking down the enlarged poi'- tions to allocate metal for the counterweighted throws, and, Vthen shaping the throws and journals substantially to the desired contour. j

4. The `method of making die-forged, multi-throw crank-shafts having integral counter' weights, which comprises iirst torming a substantially straight blank having longitudinally spaced portions of relatively large and small cross sections, and, while maintaining the central. portion ot the blank substantially straight, die-forging the same to form the small portions into journals and the enlarged portions into counterweighted throws by successively applying the pressure of roughing-out and shaping dies transversely to the blank and substantially at right angles to the plane ot' the formed throws.

5. The method of making die-forged, multi-throw crank-shafts having integral counterweights and journals on both ot the arms of each throw, which comprises forining a substantially straight blank having longitudinally spaced protuberances or eny largements of substantially the dimensions and positions of the counterweigh'ted throws, and then forming and shaping the journals and throws by applying the pressure of forging dies ina direction transverse to the plane or planes of the formed throws.

6. The method of making die-forged, multi-throw crank-shafts having integral counterweights and journals on both of the arms of each throw, which comprises forming a substantially straight blank having longitudinally spaced protuberances or enlargements of substantially the dimensions and positions of the counterweighted throws, and then, and while maintaining the central portion of the blank substantially straight, die-forging the enlargements of the blank into counterweighted throws and the other portions into journals by subjecting the blank successively to roughing-out and contour-shaping die impressions both adapted to apply pressure to the blank in a direction substantially at right angles to the plane of the formed throws.

7. The process of forging multi-throw crank-shafts which comprises enlarging the cross-section of a plurality of spaced portions of a bar to form a blank, then, while maintaining the axial portion of the blank substantially straight, `aartially dividing the enlargements transversely to allocate metal for th-e crank arms and pins, and then shaping the blank to substantially the desired contour.

' 8. The process of forging multi-throw crank-shafts which comprises enlarging the cross-section of a bar at a plurality of spaced portions corresponding in number to the throws, then partially dividing each enlargenient by indent-ing opposite sides thereof between opposed elements of breaking down die-impressions and then die-shaping th-e journals and throws substantially to the desired contour.

9. The process of making die-forged, multi-throw crank-shafts having counterweights forged integrally therewith, which comprises reducing the cross-section of a plurality of longitudinally spaced portions of a bar to thereby enlarge the intermediate portions, then transversely indenting the opposite sides of kcertain of the enlargements to partially divide the same and allocate metal for counterweighted crank arms, and then shaping the parts substantially to the desired contour.

l0. The process of making die-forged, multi-throw crank-shafts having counterweights forged integrally therewith, which comprises reducing the cross-section of a plurality of longitudinally spaced portions of a bar to form a plurality of enlargements, onel for each throw, then, while maintaining the central portion of the blank ysubstantially straight, transversely indenting the opposite sides of each enlargement between opposed elements of a roughing-out die-iinpression to partially divide the saine and allocate metal for the Countcrweightcd arms and pin of the corresponding throws and then die-shaping the journals and counterweighted throws substantially to the desired contour.

1l. The process of making die-forged, multi-throw crank-shafts having integral journals and counterweiglits on both olf lthe arms of each throw, which comprises redneing the cross-section oi a bar at a plurality of longitudinally spaced portions, ono for each journal, and thereby form a plurality of intermediate protuberances or enlargements, one for each throw, then, while maintaining the axial portion of the blank substantially straight, subjecting it. to the aetion of roughing-out die-impressimis having opposed elements for partially dividing each enlargement transversely and then to the action of shaping die-impressions to bring the journals and connterweighted throws suhstantial'ly to the desired contour.

l2. The process of making die-forged, multi-throw crank-shal'ts having integral journals and counterweights on both of the arms of each throw, which comprises reducine the cross-section of a bar at a plurality ot longitudinally spaced portions, one for each journal, and thereby forming a plurality of intermediate protuberances or enlargements, one for each throw, then subjecting the blank to the action of roughing-out dieinipressions adapted to apply pressure to the blank substantially at right angles to the plane ot' the formed throws and having opposed transverse, wedge-sluiped, die-elements for partially dividing each enlargement and thereby allocate metaly for the corresponding counterweighted crank arms and pins, and then subjecting the rough-out blank to the action of contour-shaping die-in'ipressions.

13. The method of 'forging crank-shafts and the like, whichl comprises die-forging a heated bar to enlarge the cross-sectionbf portions thereof, then subjecting the blank to a second die-forging operation'to partially transversely divide certain of the enlarged portions while preventing the axial elongation of such` portion or portions. and then die-forging the blank to the desired contour.

11i. rEhe method of forging an integral crank-shaft or the like, which comprises dieforging a bar blank to enlarge the cross-section of a portion oi" the blank and reduce the cross-section of the adjacent pintions, then, and while preventing the axial elongation of the enlarged portion, transversely indenting the opposite sides thereof to partially divide the same and allocate metal .for a pair of adjacent transverse arms or projections, and then die-shaping the blank to the desired contour.

l5. The method of forging crank-shafts and the likev` which comprises turning a heated bar between dies to reduce the crossloo section of spaced portions of the bar and enlarge the cross-section of the intern'iediate portion, then forging the blank between die-v impressions lia'ving pairs ot' opposed elements :for engaging 'the reduced portions of the blank and a pair oi opposed wedge-shaped die-elements for partially transversely dividing 'the enlarged portion thereof to thereby vallocate metal for two adjacenttransverse arms or projections, and then die-torging the blank to the desired contour.

lo. The method ot 'forging an integral crank-shalt, which comprises turning a bar ol substantially unitorm cross-section between dies having an ovoidal recess to thereby enlarge the cross-section ol a portion ot the blank and reduce the taboes-section ot the adjacent portions then subjecting the blank to die-impressions having opposed. wedgeshaped die elements to partially transwersely divide the enlarged portion, and then diefashioning the blank to shape the partially divided enlarged portion into the cheeks and pins of a crank and the reduced portions into journals, all oil substantially the desired contour.

1,7. The method ot forging an integral crank-shaft, which comprises tirst turning a bar between 'forging dies having iniliressions provided with rounded surfaces to reduce longitudinally spaced sections oit the blank and torni journal portions, and also enlarge an, .intermediate section, then sulijecting the blank to impressions having opposed elements lor engaging and ronghing out the journal portions and opposed, transverse, die-elements for partiallyr dividing the enlarged portions to thereby allocate metal 'for a pair ot counterweighted crank arms and an intermediate `pin and then dieshaping the counterweighted crank arm, pin and journal portions ot the blank substantially to the desired contour.

18. The method of forging an integral crank-shaft, which coniprises turnin a bar ot' substantially uniform cross-section between forging dies having channels provided with one or more oval-shaped recesses to reduce the cross-section of longitudinally spaced portions oit the blank and enlarge the cross-section of one or more intermediate portions, and then, and while maintaining the axial portion of the blank substantially straight, die-'forging the blank to Jform the reduced portion into journals and enlarged portions or portion each into a throw comprising a crank pin and a pair of crank arms or cheeks having integral counterweights.

19. The method of forging an integral crank-shaft, which comprises turning a bar of substantially uniform cross-section between forging dies having channels provided with one or more oval-shaped recesses to reduce the cross-section ot longitudinally spaced portions oi the blank and enlarge the cross-section of one or more intermediate portions, and then die-forging the blank to torni the reduced portions into journals and the eiilarged portions each into a throw comprising a crank-pin and a pair of crank arms or cheeks having integral counterweights, by subjecting the blank to die-iinpi'es:-;ions adapted to apply press ire lo the blank transversely of the plane or planes ot the termed throws.

20. The method oi' forging an integral crank-shaft, which comprises turning ay bar ot substantially uniform cross-section between 'forging dies having c iannels provided with one or more oval-shapal recesses to reduce the cross-section ot longitniilimfilly spaced portions t the blank and enlarge the cross-section ot one or more intermediate portions, and then die-forging the blank to Atorni the reduced portions .into journz-ils and the enlarged portions each into a irow having a pair olf integrally countcrwcightcd crank arms or cheeks, by subjecting the blank lirst to the action o'l roughing-out die impressions adapted to apply pressure substantially a@ right angles tothe plane of the Yformed tl1ro;vs and having opposed wedge-shaped elements tor partially dividing each enlargement transversely, and 'then to the action ot contour-shaping die-iinpressions.

Q1. The method ot .torming die-forged, multi -throw crank-sbatte. which comprises first forming a substantially straight blank having substantially synnnetrical, longitudinal portions alternately ot reduced and enlarged cross-section with the grain or liber ot the metal adjacent the surface and axes ot the blank substantially parallel thereto respectively, then die-forging the reduced portions into journals and the enlarged portions each. into a connier-weighted throw by subjecting the blank successively to roughing-out and contorni-shaping impressions both adapted to apply pressure to the blank transversely to the plane or planes ot the formed th rows and having opposed wedge-shaped and sul stantially abutting die-elements respectively ttor transversely dividing the enlarged portions o't the blank to thereby form the spaces between the counterweighted arms or cheeks ot the throws.

22. Apparatus `lor forging multi-throw crank-shafts comprisingrelatively reciprocating die members having breaking down or roughing out impressions arranged to apply pressure to the blank transversely to the plane or planes ot. the throws formed thereby and having` pairs oi transverse, op-

ing relatively reciprocating die-members having impressions for 'forming the throws in a common plane by the application of pressure to a blank in a direction substantially at right angles to the plane ot the formed throws, the impressions ot the die-members having pairs ot opposed elements extending t 'ansversely ot the die-cavity and on opposite sides ot the axis of the cavity and arranged to divide the protuberances ot the blank and torni the spaces between the counterweighted crank arms or cheeks of the throws.

24. Apparatus for forging a multi-throw, counterweighted crankshaft from a blank having a plurality ot protuberances, comprising relatively reciprocating die-members havingimpressions for toi-ming the throws by the application ot pressure to the blank in a direction transverse to the plane or planes oi the termed throws, the impressions of the die-meinbers having pairs ot' opposed wedge-shaped elements ttor partially dividing the protuberances ot the blank transversely and allocating metal for integral coimterweights.

25. i"\1.)paratus for forging a multi-throw crankshaft from aI substantially straight blank having a plurality ot protuberances, one for each throw, which comprises rela tively reciprocating die-members having substantially symmetrical impressions tor roughing out the ournals and counterweighted throws by the application ot' pressure to the blank substantially at right angles to the common plane ot the formed throws,`the impressions of the die-members having pairs of opposed, transverse, wedge-shaped die-elements for partially dividing the protuberances of the blank ann allocating metal to term the spaced counterweighted crank arms or cheeks of the throws.

26. Apparatus lor :forging counterweighted, n'iulti-throw crank-shafts rom a rolled bar of substantially uniform cross-section, comprising relatively reciprocating diemembers having impressions for forming the bar into a substantially symmetrical blank having alternate, convexly and concavely roundedlongitudinal portions ot enlarged and reduced cross-section respectively, and impressions for forming the reduced portions into ournals and the enlarged portions each into counterweighted throws by thel application ot pressure to the blank transversely ot' the plane or planes of the tormed throws.

27. The method of making multi-throw, counterweiglited crank-shafts comprising the following die-forging operations: (l) forming a bar into a substantially straight blank having longitudinal spaced protuberances or enlargements having convexly rounded surfaces, (2) re-shaping the blank to bring the longitudinal sections ot the protuberances into substantially rectangular form, (3) forming the counterweighted throws, one from each ot the protuberances` by the apiilication ot pressure to the blank transver; yly ot the formed throws, and (el) bringing the journals and throws substantially to the desired contour.

2Q. Apparatus for forging a n'iulti-throw crank-*shaft 'trom a substantially straight blank having a series ot reduced portions and intermediate enlargements, one ilor lach throw, comprising relatively reciprocating die members having impressions tor roughing out the journals and throws by application of pressure in a direction transverse to the plane or planes oit' the formed throws, the, opposed journal formin elements ot the impressions being arranged to engage reduced portions oi the blank on opposite sides oi each enla gement and prevent the axial elon` gation thereof and the tlnow-tornring cavities having pairs ot opposed, wedge-shapelil die-elements for partially transversely dividing each enlargement of the blank and thereby allevate metal for the crank arms and pins.

ALBERT J. LARCHER.

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