US3105399A

US3105399A - Forging press

Info

Publication number: US3105399A
Application number: US856415A
Authority: US
Inventors: Strugala Alfred; Sporenberg Willi; Schmidt Heinz
Original assignee: Wagner and Co Werkzeugmaschinenfabrik Mbh
Current assignee: Wagner and Co Werkzeugmaschinenfabrik Mbh
Priority date: 1958-12-02
Filing date: 1959-12-01
Publication date: 1963-10-01
Anticipated expiration: 1980-10-01

Description

Oct. 1, 1963 A. STRUGALA ETAL.

FORGING' PRESS 5 Sheets-Sheet 1 Filed Dec. 1, 1959 Oct. 1, 1963 A. STRUGALA ETAL 3,105,399

FORGING PRESS Filed D80. 1. 1959 5 Sheets-Sheet 2 Def. 1, 1963 STRUGYALA ETAL 3,105,399

FORGING PRESS Filed Dec. 1, 1959 S'Sheets-Sheet 5 United States Patent 3,1055% FGRGE'JG PRESS Alfred Strngala, Dortmund, Willi Sporenberg, Dortmund- Aplerhecir, and Heinz Schmidt, Dortmund, Germany, assr'gnors to Wagner 8; (30., Werkzeugmaschinen m.b.H., Leann-and, Germany Filed Dec. 1, 15, Ser- No. 856,415 Claims priority, application Ge many Dec. 2, E58 1 Claim. {f1 78%) The present invention relates to forging presses in general, and more particularly to an assembly-line type forging press for the manufacture of various forgings, such as the races for anti-friction bearings and the like. When the press is utilized for transforming a blank which is heated to forging temperature into the annular shape of a race for ball bearings, the transformation occurs intermittently in a series of successive steps during which the progressively treated blank is automatically advanced between the treating stations and need not be reheated during the treatment.

For example, a blank which is cut from a rectangular or otherwise shaped billet may be flattened into a discoid shape, formed with a bore, calibrated by increasing one or more of its dimensions, and finally transferred to a rolling mill or the like. The novel forging press may also embody means for loading fresh blanks onto a conveying device, an oven for heating the blanks to temperatures required for the forging operation, as well as means for automatically removing the shaped articles from the conveying device. The treatment of workpieces which need not be subjected to a rolling action may be terminated right in the forging press. The presses of the type to which the present invention pertains normally embody a series of shaping tools each of which may perform one, two or more operations upon a workpiece. For example, the tools may form a blind bore or a through bore in a blank, remove the burrs from a workpiece, deform the workpiece into a desired shape, and so forth. Sinular types of forging presses may be utilized in the manufacture of drawn sheet metal parts and the like, and their shaping tools are preferably reciprocable by a single ram or the like.

The present invention has for one of its objects to solve an extremely difiicult problem which constantly arises in forging presses of the assembly-line type, namely, how to arrange the blanks and the conveying means therefor on the workbench of the forging press in order that the successive action of several shaping tools upon the blanks may be performed within a very short period of time without requiring a reheating of blanks during their transformation into shaped articles. This is particularly important when the blanks must be subjected to the action of many shaping tools because the advance of blanks between the successive stations must occur with very little loss in time if an excessive cooling is to be avoided before the operation is completed.

Another object of the invention is to provide an assembly-line type forging press with a novel arrangement of synchronized actuating means for automatically advancin g, rotating, lifting or otherwise moving a series of blanks or workpieces between the successive treating stations not only with little loss in time but also in such a way that the apparatus requires very little supervision and that its moving parts are subjected to lesser wear and tear.

A further object of the invention is to provide a forgaliases Patented Get. 1, 1963 ing press of the above outlined characteristics which may be utilized in connection with the manufacture of a wide variety of shaped articles and which is constructed and assembled in such a way that the various shaping tools, either alone or in pairs, may be mounted very close to each other.

A concomitant object of the invention is to provide a novel system of conveyors for the gripping members which transport the workpieces bet-ween the treating stations of an assembly-line type forging press.

A further object of the instant invention is .to provide an improved actuating assembly for the conveying elements which move the workpieces and the gripping mem bers therefor between the successive treating stations of a forging press, the construction and operation of the actuating assembly being such that it is capable of imparting two or more difierent movements to one or more sets of grippers, the number of such movements depending upon the type of shaping tools and also upon the nature of treatment to which the workpieces must be subjected.

It is also an object of the present invention to provide a forging press which may be readily adapted and modified for use in connection with the manufacture of different shaped articles, wherein one or more treating stations may be added or eliminated without requiring substantial modifications in the arrangement of its parts, and whose workbench is constructed in such a way as to permit access to all component parts as Well as to permit convenient observation of the forging operation.

An additional object of the invention is to provide a forging press which requires a single source of power for its operation and wherein the movements of various shaping tools as well as of the workpieces and of their grippers may be brought about with simple and very rugged actuating and motion-transmitting assemblies.

The above and certain other objects of the invention are retained by the provision of a forging press whose workbench supports a pair of elongated preferably parallel conveying elements located below a series of vertically reciprocable overhead shaping tools which receive motion from the press ram to travel in a given working rhythm into and away from engagement with the workpieces located on the workbench between the conveying elements. The conveying elements are provided with or connected to grippers which are adapted to engage or release the Workpieces therebetween and to convey the workpieces in the working rhythm of the press into requisite position below the aligned shaping tools. Means is provided for moving the conveying elements, the grippers and the workpieces in a first direction, and for returning the conveying elements with the grippers but without the workpieces in a second direction counter to the first direction. The press also embodies means for moving the conveying elements with the grippers toward and away from each other, thus enabling the grippers to alternately engage and release the respective workpieces, again in synchronism with other movements of various component parts of which the forging press consists.

In certain instances, e.g. when the workpieces must be caused to perform other than purely linear movements in order to advance into requisite position with respect to the serially arranged overhead shaping tools, the press also embodies means for rotating and/ or reciprocating selected pairs of grippers and the corresponding workpieces, for

3 example, when a workpiece must be lifted from the cavity of a matrix-shaped countertool, when the same side of a workpiece must be acted upon by successive overhead tools, or when a workpiece is out of horizontal alignment with the other workpieces or blanks.

The actuating means for the conveying elements and for the grippers may be operated by a separate drive, for example, with the help of suitable control elements of a construction somewhat similar to the construction of control elements used in many types of machine tools, and whose operation is synchronized with the operation of the overhead shaping tools. lowever, and particularly if the assembly-line type forging press (i.e. a forging press using a series of aligned overhead shaping tools) is utilized in the manufacture of comparatively small articles, it is advisable to operate the actuating means for the conveying elements and their grippers, either directly or indirectly, by the main ram of the press which also actuates the overhead shaping tools. The operative connection between the ram and the conveying elements may consist of purely mechanical parts, e.g. cams, followers, connecting rods, bell crank levers, toothed racks, gears, and the like. Such arrangement is very simple and compact so that the entire machine and particularly the actuating devices for the work-conveying elements occupy little space, and the shaping tools may be placed close to each other.

It is often required that a blank or a partially treated workpiece should be inverted in the forging press before it comes into alignment with a selected overhead shaping tool. For example, when the forging press is utilized in the manufacture of races for ball hearings or similar annular articles, the blank is placed onto a flat supporting plate and is acted upon by a first overhead shaping tool which forms therein a recess or blind bore. In the next step, the partially apertured blank is inverted and subjected to the action of another overhead shaping tool which completes the formation of a through bore to trans form the blank into an annular body. 'This procedure is preferred because it prevents the formation of burrs on the forging. In such instances, the grippers utilized for transferring a recessed blank beneath that overhead shaping tool which completes the formation of a through bore must rotate through 180 degrees to invert the blank before the latter is acted upon by the bore-forming instrumentality. This may be achieved by connecting the corresponding set of grippers with toothed wheels and by placing toothed racks into the path of such wheels so that the latter are rotated at a selected stage of the operation and invert the blank before a through bore is formed therein. Alternately, the means for rotating selected pairs of grippers may comprise friction-generating surfaces and friction rollers whose peripheral zones engage for a given period of time with the friction-generating surfaces to bring about a desired angular movement of the grippers and of the workpiece therebetween. In both instances, the workbench is preferably provided with a suitable recess or cutout to permit unimpeded rotation of selected grippers and of the workpiece, the location of the recess being selected in such a way that the workpiece will travel thereover while it is caused to perform a rotary move,- ment. When a set of grippers is caused to perform a rotary motion during the advance of the conveying elements, it is advisable to hold such grippers against rotation except in selected zones of the workbench, for example, by forming the grippers with flat surfaces which normally slide along the top surface of the workbench.

If the blanks must be supported in matrices which are aligned with selected overhead shaping tools, the grippers should be capable of performing vertically reciprocating movements in order to lift the workpieces out of the cavity of a matrix or to engage an elected workpiece at a level above the level of the other workpieces. This may be attained by combining selected grippers with suitable mechanical, hydraulic, pneumatic or electric reciproeating devices, e.g. eccentric rollers, hydraulic or pneumatic cylinder and piston assemblies, electromagnets, or the like.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claim. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of certain specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a central vertical section through an assemblyliue type forging press for the manufacture of comparativel" small annular products, the means for reciprocating the ram being omitted and the section being taken along t e line li of FIG. 2, as seen in the direction of arrows;

FIG. 2 in a horizontal section through the forging press taken along the line llll of FIG. 1, as seen in the direction of arrows;

HS. 3 is an enlarged fragmentary detail view'of FIG. 2 with the workpieces omitted, showing a series of pairwise arranged grippers for the workpieces;

FIG. 4 is a side elevational view of the structure shown in FIG. 3;

FlG. 4a is a fragmentary section taken along the line lVa-lVa of FIG. 3, as seen in the direction of arrows;

FIG. 5 is a vertical section through the forging press taken at right angles to the view and along the line VV of HG. l, as seen in the direction of arrows;

FIG. 6 is a greatly enlarged sectional view of a modified gripper and of eccentric reciprocating means therefor, the section being taken along the line VIVI of FIG. 7, as seen in the direction of arrows;

FIG. 7 is a vertical section taken along the line VH VII of FIG. 6, as seen in the direction of arrows; and

FlG. 8 is a vertical section through a different gripper which is reciprocable by the pressure of a fluid medium.

Referring now in greater detail to the illustrated embodiments, and first to FIGS. 1 to 5, the forging press therein shown comprises two pairs of spaced vertical posts or uprights 1, 2. for guiding a comparatively wide vertically reciprocable ram 3. The latter is operated by a non-represented drive, such as a suitable crank assembly or an equivalent actuating means. As can be observed in FIG. 1, each of uprights l, 2 carries one or more vertical ribs or tracks 4 for accurately guiding the ram 3 during its reciprocatory movements toward and away from the workpieces therebelow. The rear sides of uprights l, 2 carry a vertical wall 5 on which the non-represented drive means for the ram 3 is usually mounted. The ram carries a series of downwardly extendin uniformly spaced overhead shaping tools, shown in FlG. l as consisting of an upsetting tool 6, a drop forging power hammer '7 which not only shapes the workpiece therebelow but simultaneously forms therein a blind bore, and a third tool 3 whose purpose is to complete the formation of the bore in a workiece, to further expand the latter and to simultaneously calibrate the product, i.e. to impart to the product its final dimen sions before removal from the forging press either for storage or for further processing, it necesasry.

The workbench of the forging press comprises a horizontal plate-like power member 5: which extends over the full width of the apparatus and is formed with an upwardly projecting central extension 9a for releasably supporting a second plate it The latter may be screwed to or otherwise connected with the extension 9:: of the bottom plate member 9. The plate it is connected with and supports a horizontal top plate 11 which extends substantially from the central zone of the upright l to the central zone of the other upright 2. The top plate 11 consists of a highly resistant, high-quality steel or an equivalent material and constitutes a simple countertool for the overhead tools d8. The width of the last mere tioned plate 11 preferably approximates the maximum width or the diameter of workpieces which are treated in the forging press. As is best shown in FIG. 2, the top plate 11 is located between a pair of elongated parallel, horizontal, flat conveying battens or bars 12, 13 which act as conveying elements for the workpieces. Each of the conveying

elements

12, 13 is mounted on its own slideway 14 formed in the workbench of the press.

As is best shown in FIG. 2, each of conveying

elements

12, 13 supports and is connected with four spaced

grippers

15, 16, 17 and 18 which are capable of engaging and tranferring the workpieces to vairous treating or processing stations of the forging press. The jaws of pairwise arranged grippers 18 are aligned transversely of the longitudinal direction of their conveying

elements

12, 13, i.e. these grippers are arranged in mirror reverse with respect to a vertical plane passing centrally through the work-supporting top plate 11 on the workbench. A fifth pair of grippers, identified by the reference numerals 19, is also mounted in mirror reverse on the conveying

elements

12, 13 but in such a way that these grippers may rotate in their respective bearings 21 about a common axis which is perpendicular to the direction in which the

elements

12, 13 are movable in their ways 14. The direction in which the

elements

12, 13 advance is indicated in FIGS. 1 and 2 by the arrow 21. Each gripper 19 is fixed to a horizontal spindle 220 which carries at its free outer end a spur wheel 22. As may be observed in FIG. 3, the length of strokes performed by the

elements

12, 13 is indicated by the reference character h, each such stroke corresponding to the distance between the centers of adjacent gripper pairs, e.g. of grippers 1'7, 19 or of

grippers

16, 19. The conveying

elements

12, 13 are shown in their starting position, that is, before they begin to perform a stroke 12 in the direction of arrow 21. A pair of toothed racks 23 is mounted on the plate 19; these racks are located in the path of the spur wheels 22 at the outer sides of

elements

12, 13. The teeth of the racks 23 come into mesh with the teeth of wheels 22 when the grippers 19 are caused to advance in a direction to the right of FIG. 3, whereby the spindles 22a cause the grippers 19 to rotate through exactly 180 so as to invert the workpiece which is held between the jaws of grippers 1?. It wfll be noted that the plates 9, 1t": and 11 are formed with aligned cutouts which define a recess 24 between the toothed racks 23 so as to permit unimpeded rotation of the grippers 19 and of the workpiece which is held therebetween. Of course, the depth of the recess 24- need not be exactly as shown in FIG. 1, it being sufficient to form cutouts in the plates 1% and 11, particularly the former is of sufficient thickness so that the cutouts in the

plates

19, 11 insure free rotation of a workpiece and of the grippers 19 while the latter advance with the conveying

elements

12, 13 in the direction of arrow 21.

The top plate 11 supports a series of workpieces which are acted upon by the

overhead instrumentalities

6, 7, 8 in that order. As is shown in FIG. 2, the grippers 15 may hold an unfinished rectangular blank 25 which was previously separated from a non-represented billet. Before being placed between the grippers 15 by a nonrepresented manipulating device, each blank 25 is heated to requisite forging temperature in an automatically operated oven or the like, not shown. In their position as illustrated in FIGS. 1 and 2, the grippers 15 are located at the first station of the assembly-line type forging press which may also be called the receiving or loading station for the raw workpieces. The successive treating stations of the press are occupied by the gripper pairs 16, 19, 17 and 18 in that order whenever the conveying movement of

elements

12, 13 in the direction of arrow 21 is about to begin. The partially treated second workpiece 25 shown between the substantially V-shaped jaws of grippers 16 was already subjected to the upsetting action of the overhead tool 6. As can be observed in FIG. 2, the tool 6 transforms a rectangular blank 2-5 into the discoid body 25 but without forming a bore or even a recess in the latter. The workpiece 27 betwee the jaws of grippers 19 is formed with a coaxial circular depression or blind bore 27a (see FIG. 1) which does not extend all the way through the body of the partially finished article 27. As is also shown in FIG. 1, the workpiece 27 receives its shape from the suitably formed die 7a at the lower end of the hammer 7; this die is formed with a recess corresponding to the shape of the article 27 which latter thus constitutes the next stage in the transformation of the workpiece 25 over the stage 26 into the partially finished product held between the jaws of grippers 19. The finished article 28 held between the jaws of aligned grippers 17 has a through bore 28a which is formed by the stud 8a of the tool 8 shown in FIG. 1. The stud 8a eliminates the web of material remaining between the bottom of the blind bore 27a in the workpiece 27 and the plate 11 therebelow. However, and as will be fully described hereinafter, the position of this web and of the blind bore or ecess 27a is inverted by the toothed racks 23 and spur wheels 22 before the action of the stud 8a begins. In addition to completing the formation of central bore 28a, the tool 3 also increases the diameter of the article 28 and subjects the latter to additional deformation, if necessary, in order to calibrate the product, i.e. to impart thereto the desired final dimensions. The annular article 28' shown in FIG. 2 between the jaws of grippers 13 is the same as the article 28. It is in a position in which it is ready for removal from the space between the jaws of grippers 18 and, because presumed to be removed in the position of the parts as shown in FIG. 2, is illustrated merely in phantom lines. The means for withdrawing the annular product 28 from the jaws of grippers 18 may be of any known design and is not shown in the drawings. For example, such withdrawing means may advance the articles 28' into a rolling mill for annular shapes or toward any other additional processing station.

As can be observed in FIGS. 2 and 3, each of gripper pairs 15, 16 has limited freedom of movement toward and away from each other by being mounted in aligned pa rwise arranged slide plates 31) carried by the

elements

12, 13, respectively. Each of

grippers

15, 16 is formed with or carries at least one but preferably two guide bolts or rods 3011 which are slidable in the respective plates 3% and are surrounded by coil springs 31 whose function is to permanently urge the gripper pairs 15, 16 toward each other. The extent to which the jaws of gripper pairs 15, 16 may move toward each other is determined and is variable by adjusting nuts 32 which are screwed onto the externally threaded outer end portions of the rods 39a.

The means for advancing the conveying

elements

12, 13 along the upper side of the plate member 113 comprises a connecting or push rod 34 which is reciprocable by a plate cam 33. The latter is fixed to a shaft 35 which is connected to an element of a crank drive or the like used for operating the ram 3. The peripheral cam surface of plate cam 33 is tracked by a series of roller followers 37 which are conneo ed to the head 36 of the connecting rod 34. The latters lower end is articulately connected to an adjustable lever arm 38 which is mounted on a horizontal shaft 39 rotatably carried by the upright member 2 of the forging press. The shaft 39 extends over the full width of the apparatus and each of its ends carries a'lever arm 41?. The free lower end of each arm 40 is articulately fixed to a push rod 41 which latter, in turn, is artioulately connected with a slidable traverse or crosstie rod 42. The rod 4-2 is guided in a pair of slides 43 and is connected with the conveying

elements

12, 13 by means of T -shaped drivers or dogs 44 which permit movements of

elements

12, 13 in directions toward and away from each other.

To that end, the drivers are sl idable in suitable grooves formed in the crosstie rod 42. When the cam 33 causes the connecting rod 34 to move in upward direction, the rod will pivot lever

arms

58 and 40 about the shaft 35 in counterclockwise direction whereby the

parts

41, 42 and 44 cause the conveying

elements

12, 13 to advance in a horizontal plane in the direction of arrow 21. On the other hand, the downwardly advancing rod 34 causes the lever arms 38, 4-4 to pivot in clockwise direction whereby the

elements

12, 13 are advanced in a direction to the left of FIG. 1. Thus, the lever arms 33, 4-21 constitute means for transforming vertically reciprocating movements of connecting rod 34- into horizontally recipro cating movements of conveying

elements

12, 13 in and counter to the direction of arrow 21.

The means for simultaneously moving the gripper pairs 15 to 19 and the conveying elements l2, 13 toward or away from each other is shown in FIGS. 1 and 5. It comprises a pair of substantially vertical push rods 45 each of which is longitudinally adjustble, as at 46. The rods 45 are guided in brackets 47 which are carried by the uprights 1 and 2. These brackets also serve as stops for the upper caps 48 of helical expansion springs 49. As is shown in FIG. 5, the lower end of each push rod 45 is externally threaded, as at 45a, to mesh with a. tensioning nut which bears against the underside of the lower cap or disht5l of the respective resilient element 4%. The latter constantly tend to move the push rods 45 in downward direction and thereby urge the roller followers 54 carried by the bell crank levers 52 into firm engagement with reciprocating cams 55. Each follower 54' is rotatably connected to one arm of the respective bell crank lever 52 whose other arm is articulately fixed to the upper end of the adjacent push rod 45. Both bell crank levers 52 are fixed to and are rotatable with a horizontal shaft 53 which is mounted in the frame of the forging press. The shaft 53 insures that the bell crank levers 52 and hence the push rods 45 move in unison and to the same extent when the members 52 are rocked by their respective earns 55. The latter are fixed to the ram 3 so as to bring about upward movement of push rods 45 against the bias of resilient elements 4-9 when the ram 3 descends toward the workbench of the forging press.

The lower ends of push rods 45 are articulately fixed to a pair of spaced slotted crank arms 56. The pivot pins 57 of the rods 45 are slidable in the slots of respective crank arms 56, and the latters angular position may be adjusted by means of adjustmg screws 53 each of which bears against one of the pivot pins 57. Each rank arm 56 is connected to a short transverse horizontal shaft 69 and each of these shafts is pivotally mounted in one of two frame members or housings 59 which form part of the forging press. Adjacent to its crank arm 56, each shaft 61? carries a toothed segment 61 whose purpose will be described in greater detail hereinafter. As can be observed in FIG. 1, the frame members 59 extend at right angles to the longitudinal direction of

elements

12 and 13.

Each frame member 59 is mounted on a stepped portion of the plate member 9 and extends upwardly to the level of the slideways 14 in the plate 10. In the following passage of this description, only the parts mounted in one frame member 5? will be described because the other frame member is of identical construction and contains identical parts, the purpose of such parts being to reciprocate the conveying

elements

12, 13 with the gripping means to 19 thereon in directions toward and away from each other.

The upper side of the frame member 59 is formed with or is connected to a pair of upwardly extending guides or tracks 62 for a small stationary support or base 63 and two shiftable supports 64-, 65. The Width of the non-shiftable stationary support 63 corresponds to'that'of the top plate 11 and, as shown in FIG. 5,

the latters underside rests on the upper face or" the support 63. A toothed gear 66 is mounted in the support 63 for rotation about a horizontal axis; this gear meshes with the teeth of a horizontal lower toothed rack 67 and also with the teeth of a horizontal upper toothed rack 68. The racks 6'7, 63 are slidably mounted in bearings 6% in the support 63. The lower rack 67 also meshes with the teeth of one of the aforementioned toothed segments 61 and is shiftably guided in a second bearing 69a installed in a vertical rib 76 forming part of the frame member 59. The free left-hand end of the lower rack 6'7 is connected to the lower part 71 of the shiftable support 64 by means of a pin 72 and by a non-represented clamping plate or the like. The righthand end of the upper rack 68 is connected to the lower portion 73 of the second shiftable support 65 in similar fashion, i.e. by a pin 72a and by a non-represented clamping plate, clip or the like. The left-hand end of the rack 68 is guided in bearings 69b mounted in a second vertical rig 74 forming part of the frame member 59. It will be noted in FIG. 5 that the rack 68 is freely shiftable through the 1eft-hand supporting member 64 because the latter is provided with a horizontal through bore '75, i.e. the reciprocating movements of the upper toothed rack 68 in no way affect the position of the supporting member or base 64.

The upper sides of

bases

64, 65 are formed with upwardly extending tongues or ridges 76 which project into complementary recesses provided in the undersides of conveying

elements

12, 13, respectively. The

parts

45, 56, 57, 6t), 61, 64-, 65, 66, 67, 68 and 76 constitute means for moving the conveying

elements

12, 13 in directions toward and away from each other, i.e. in direc tions at right angles to the direction of the arrow 21. Owing to the provision of two such transversely reciprocating drives for the

elements

12, 13, the latter are readily reciprocable at right angles to the direction of arrow 21 Whenever the push rods :5 are set in motion. As can be seen in FIG. 1, the spacing of frame members 59 is somewhat less than the length of

elements

12, 13 so that the latters end zones can be acted upon by spaced pairs of supporting

members

64 and 65, respectively. Thus, the conveying

elements

12, 13 can reciprocate the

grippers

15, 16, '19, 17, 13 into and away from engagement with the

workpieces

25, 26, 27, 28, 29, respectively. All grippers are caused simultaneously either to engage with or to release the respective workpieces. The provision of above described biasing means 3-1 for the grippers 15, .16 is often necessary because the dimensions of blanks 25 as Well as of partially finished workpieces 26 may vary within a rather wide range. Without the provision of springs 3-1, it could occur that the

workpieces

25, 26 would be properly held by the

grippers

15, 16, respectively, while the grippers 19, '17 and 18 could not -satis factorily engage with the respective workpieces 27, 2.8 and 28'. The latter need not be held in spring-biased grippers because their dimensions are always or nearly always the same owing to the action of

tools

7 and 8 thereupon. Of course, and particularly-if the dimensions of successively treated blanks 25 are substantially the same, the resilient biasing means 31 for

grippers

15 and 16 may be dispensed with or, alternately, it is often sufiicient to provide only the rotary grippers 19 with spring-biased jaws. This last mentioned modification is not shown in the drawings.

It will be seen that the improved assembly-line type forging press comprises means in the form of the ram 3 for simultaneously moving the

overhead shaping tools

6, 7 and 8 toward or away from the workpieces on the work-supporting plate '11; means including the connecting rod means 34 for reciprocating the conveying

elements

12, 13 and the grippers 15 to 19 with or without the workpieces from a starting position in and counter to the direction of the arrow 21 in order to intermittently advance the workpieces into proper position beneath the adjacent

overhead shaping tools

6, 7 and 8; and means including the push rods 45 for moving the

elements

12, 13 in a horizontal plane toward and away from each other whereby to move the grippers 15 to 19 into or away from engagement with the respective workpieces. It will be readily understood that, when the grippers 15 to 19 are out of engagement with the workpieces and the connecting rod means 34 causes the

elements

12, 13 to move in a direction to the left of FIG. 1, i. e. counter to the direction of arrow 21, the workpieces will remain stationary by resting on the work-supporting plate 11. During the next movement of conveying elements 12, '13 in a direction to the right from their starting position (arrow 21), the grippers 19, for example, will engage with the workpiece 27 located below the hammer 7 and will entrain the same into requisite position below the tool 8, and so forth.

The forging press which is shown in FIGS. operates as follows:

The ram 3 is shown after the completion of a working stroke and of the subsequent return stroke, i.e. it is in its extreme upper position in which it maintains the

overhead shaping tools

6, 7 and 8 at such distance from the workpieces that the latter may be readily shifted in the direction of arrow 21. The conveying

elements

12, 13 then begin their forward stroke h from the initial or stming position in a direction to the right of FIG. 1 or 2 because the connecting rod 34 begins its upward stroke so as to shift the conveying elements in the above described manner, i.e. by means of the crosstie rod 42 which is caused to slide on its slides 43 under the action of lever arms 46) and members 41. The push rods 45 are still in the position of FIG. therefore, the grippers to 19 firmly engage with the respective workpieces -28 and cause the latter to slide along the upper side of the top plate 11 in the direction to the right of FIG. 2. It is, of course, assumed that a new blmk 25 is placed between the jaws of grippers 15 before the movement of conveying

elements

12, 13 in the direction of arrow 21 begins. The retaining action of the grippers upon the workpieces therebetween is due to the bias of springs 49 which urge the push rods into the position of FIG. 5 when the ram 3 is lifted above and away from the workbench of the press.

The crosstie rod 42 continues its movement on the guideways or slides 43 until the conveying

elements

12, 13 complete their forward stroke 72 in the direction of arrow 21. Before the just described stroke of

elements

12, 13 is completed, the ram 3 begins to descend together with the overhead tools 5-8 whereby, after the elapse of a predetermined period of time, the reciprocating cams 55 act upon the roller followers 54 and move the push rods 45 in upward direction against the bias of resilient means 4-9 as soon as

veying elements

12, 13 is completed. The crank arms 56 are lifted and pivot the toothed segments 61 in each of the frame members 59 whereby the segments shift the lower toothed racks 67 in a direction to the left of FIG. 5. The gears 66 cause simultaneous advance of upper racks 68 in a direction to the right of E16. 5 so that the

supports

64, 65 move the conveying elements and the gripper pairs 1.5-3? away from each other whereby the grippers are disengaged from the respective workpieces immediateiy after the forward stroke of conveying

elements

12, 15 is completed. In this manner, the grippers cannot interfere with the action of descending shaping tools 6, 7 and S which are moved by the ram 3 toward the workpieces therebelow. Dur ng the action of overhead tools 6S, the blank 25 is transformed into a partially shaped workpiece 26, the workpiece below the tool 7 is transformed into the shape of the member 27, and so forth.

When, or even before the ram 3 begins its return stroke in upward direction, the connecting rod 34 starts to move downwardly to return the conveying

elements

12, 13 in lto5 the forward stroke of cona direction counter to that indicated by the arrow 21 while the grippers remain disengaged from the workpieces and the latter thus remain stationary by resting on the upper side of the top plate 11. When the return stroke of

elements

12, 13 is completed (the length of this return stroke equals the length of the forward stroke h), the earns 55 permit the followers 54 to assume the position of FIG. 5 whereby the springs cause the respective push rods 45 to descend and to bring about engagement of the grippers with the workpieces. It will be understood that the finished article 29 was removed from the phantom-line position shown in FIG. 2 and that a new blank 25 was placed onto the loading station at the lefthand end of the work-supporting plate 11. The forging press is now ready for the next operation which is carried out in a manner as described hereinabove.

During the reciprocation of conveying

elements

12, 13 in and counter to the direction of arrow 21, the grippers 19 and the workpiece 27 between their jaws are moved as follows:

When the

elements

12, 13 move to the right of FIG. 3 or 4 to perform a forward stroke 11, the toothed wheels 22 of both grippers 1? travel over and are rotated by the respective toothed racks 23. The lower forward edge a (see FIG. 4a) of each gripper 19 is caused to descend into the recess 24 together with the forward half of the workpiece 2'7 while the

parts

19 and 27 perform the required angular movement. The lower rear edge b of each gripper 1.9 travels in a prolate cycloidal path and is lifted above and away from the respective slideway 14 while the members 19 turn. The rear upper edges c of these grippers then become the lower front edges of the same and slide along the ways 14 past the recess 24 until the

elements

12, 13 complete their forward stroke. The number of teeth on the racks 23 equals one-half the number of teeth on the respective wheels 22; therefore, the angular movement of grippers 19 is completed as soon as their edges 0 come into sliding contact with the portions of slid-sways 14 at the right-hand side of the recess 24. A sliding contact is then established between the surfaces extending intermediate the edges cd of both grippers l9 and the upper sides of slideways 14. Consequently, no further angular displacement of the grippers 19 can take place and the inverted workpiece 2'7 slides along the upper side of the plate 11.

During the return stroke of the conveying elements in the direction to the left of FIGS. 3 and 4, both toothed wheels 22 bypass the respective toothed racks 23 because the

elements

12, 13 are held apart by the push rods 45 and springs 49 in the manner as described hereinabove. Thus, the grippers 19 can rotate only when the conveying elements i2, 13 are caused to move in the direction of arrow 21. An important advantage of such arrangement is in that the parts are subjected to lesser wear and tear because the number of engagements between the wheels 22 and toothed racks 23 is out exactly in half.

in a slightly modified construction which is not shown in the drawings, the toothed racks 23 may be replaced by smooth-surfaced plates, and the toothed wheels 22 are then replaced by discoid rollers whose peripheral surfaces are coated with a brake liner or any other suitable friction-generating material. It is preferred in such modified constructions to utilize smooth-surfaced plates which are constantly biased in upward direction so as to insure satisfactory engagement with the rollers.

In the forging press which is shown in FIGS. 1 to 5, the means which complements the action of

instrumentalities

6, 7 and 8 consists of a fiat-surfaced top plate 11. However, if the desired configuration of articles to be manufactured in the apparatus of this invention is such that the workpieces must be shaped not only from above (by the overhead tools 6 to 8) but also by suitable countertools on which the workpieces rest, the corresponding grippers, e.g. the grippers 1'7 and 19, must be mounted for vertically reciprocating movements toward and away from the workbench. For example, if a countertool in the shape of a lower die or matrix is utilized, the corresponding set of grippers should be able to lift a workpiece from the cavity of the matrix. On the other hand, if the matrix-shaped countertool is provided with an ejector system, the corresponding set of grippers should be able to engage the shaped workpiece in the latters lifted position, is. after the ejector system has lifted the workpiece from the cavity in the matrix. It will be readily understood that such modified constructions may embody suitable actuating means for the reciprocable grippers Whose movements are synchronized with the movements of conveying

elements

32, 13 and of the

shaptools

6, 7 and 8.

FIGS. 6 and 7 illustrate one form of a vertically reciprocable combined ejector and gripper, hereinafter called lifting gripper. The lifting gripper 77 is fixed to a slide bar or pusher 78 of inverted U-shape. The legs 79 of the pusher 73 are slidable in a recess 3% between a pair of transverse cheeks forming part of a modified conveying element The latter also comprises a pair of bearing brackets 81 located at the longitudinal ends of the recess 3% for rotatably supporting the horizontal shaft 82a of an eccentric 82 which is rotatable in the recess 8%. The shaft 82a has an extension or trunnion 82b for a toothed gear 83 which is adapted to mesh with a toothed rack 84 thereabove. The rack 84 is rockable by a non-represented system of levers, by a hydraulic or pneumatic cylinder and piston assembly or the like to rotate the gear 83, whereby the lifting gripper 77 is caused to perform a vertically reciprocating movement at a selected stage of the operation. When the gear 83 rotates, the eccentric 82 acts upon the base of the U- shaped pusher 73 and thus transforms the angular movement of gear 83 into a vertically reciprocating movement of the lifting gripper 77. The latter is connected with two pairs of vertically reciprocable guide bolts 85 which extend through the recess 8% and also through the portion of the conveying element fill therebelow to serve as supports for helical expansion springs 85. Each of these springs acts between the underside of the conveying element 3%) and a washer 8542 which is held on the respective bolt 86 by a nut 85b or the like. The function of springs 35 is to maintain the base of pusher '78 in constant abutment with the eccentric reciprocating means 82. When the modified construction shown in FIGS. 6 and 8 is embodied in the forging press of P165. 1 to 5, the toothed rack 84 is set in motion whenever the

tool

7 or 8 begins its upward stroke with the ram 3. For example, grippers similar to the lifting gripper 77 may be utilized for lifting a workpiece from the cavity of a stationary matrix-shaped countertool which is aligned with the

reciprocable tool

6, 7 and 3.

Another type of a vertically reciprocable lifting gripper is shown in FIG. 8. The conveying element 39 is formed with a cylindrical cavity or space 91 which receives a vertically reciprocable piston or plunger 83. The latters upper end is connected to a lifting gripper 87, i.e.; the

parts

87, 88 always move in unison. The plunger 88 is also connected with a downwardly extending guide bolt 92 which projects through the portion of conveying element 89 below the cylinder space 91 and carries at its lower end a discoid stop 92:: for a helical expansion spring 93 which constantly urges the plunger 88 in downward direction. The tension of resilient element $3 may be adjusted by one or a pair of nuts 92!) which bear against the underside of the stop 92:: and are screwed onto the externally threaded lower end of the guide bolt 92. The upper side of the conveying element 89 carries a pair of arresting members 943 which limit the upward movement of the plunger 88 and hence also of the lifting gripper 87. The sealing means for preventing the escape of pressure fluid from the cylinder space 91 along the periphery of the plunger 83 and along the guide bolt 92 are not illustrated. When a hydraulic or pneumatic fluid is introduced into the cylinder space 91, the fluid pressure will overcome the retracting action of spring 93 and will cause the lifting gripper 87 to move into the position which is illustrated in FIG. 8. As soon as the pressure of fluid in the space 9 drops, the spring 93 will immediately return the plunger 88 with the lifting gripper 37 into the lowermost position. Again, the rhythm in which the fluid is introduced into the assembly of FIG. 8 is preferably attuned with the working rhythm of the forging press in which such assemblies are put to use.

It is also possible to operate the lifting grippers with the help of electric current, e.g. by suitable electromagnets or the like, particularly if the lifting grippers should perform one, two more movements with respect to their conveying elements.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claim.

What is claimed as new and desired to be secured by Letters Patent is:

A forging press for transforming blanks into shaped articles in :a series of consecutive operations, the press comprising in combination: a vertically reciprocable ram; a plurality of equally spaced aligned overhead shaping tools carried by the ram; a horizontal workbench located below the shaping tools for supporting a series of blanks; a pair of spaced horizontal parallel conveying elements movably supported on the workbench; a plurality of grippers mounted on each conveying element, the spacing of said grippers on each conveying element being equal to the spacing of said tools and the grippers on said conveying elements being arranged in pairs with each pair adapted to releasably hold a blank therebetween; means for simultaneously advancing said conveying elements and said grippers from a starting position in a first direction to move the blanks engaged by the pairs of said grippers into alignment with and beneath the consecutive shaping tools so that the shaping tools may descend simultaneously to perform a single shaping operation upon the respective blanks, and in a second direction counter to said first direction to simultaneously return the conveying elements and the grippers into said starting position; means for simultaneously moving the conveying elements and the grippers toward and away from each other whereby the pairs of grippers alternately engage and release the blanks therebetween, said last mentioned means comprising vertically reciprocable push rod means, cam means carried by the ram for reciprocating said push rod means,.

toothed segment means operatively connected with and turnable by said push rod means, first toothed rack means meshing with said segment means and reciprocable in a horizontal plane, second toothed rack means reciprocable in a horizontal plane, gear means meshing with said first and second rack means for moving the second rack means counter to the direction of said first rack means when the latter is moved by said segment means, first supporting means connected with the first rack means and with one of said conveying elements, and second supporting means connected with the second rack means and with the other conveying element, the direction in which said rack means are movable by said segment means and said gear means being perpendicular to said first and second directions; and means for rotating at least one pair of grippers with respect to said conveying elements about a common axis'perpendicular to said first and second directions whereby said one pair of grippers is adapted to invert a blank held therebetween.

(References on following page References Cited in the file of this patent UNITED STATES PATENTS Simpson Ian. 15, 1895 Candee Aug. 15, 1922 Peterson Dec. 4-, 1928 Berger Feb. 7, 1933 Nichols July 20, 1937 Bell et a1 Oct. 7, 1941 14 Morison Mar. 6, 1945 Schaefier Sept. 21, 1954 Carlsen Feb. 26, 1957 Fletcher et :11 Oct. 29, 1957 Schramm Feb. 23, 1960 FOREIGN PATENTS France Jan. 15, 1951