US3478566A

US3478566A - Knockout for forge machine

Info

Publication number: US3478566A
Application number: US605893A
Authority: US
Inventors: Ellis H Ferguson
Original assignee: Wyman Gordon Co
Current assignee: Wyman Gordon Co
Priority date: 1966-12-29
Filing date: 1966-12-29
Publication date: 1969-11-18
Anticipated expiration: 1986-11-18

Description

' NOV. 18, 1969 FERGUSON 3,478,566

KNOGKOUT FOR FORGE MACHINE Filed Dec. 29, 1966 5 Sheets-Sheet 1 Nov. 18, 1969 E. H. FERGUSON 3,478,566

KNOCKOUT FOR FORGE MACHINE Filed Dec. 29, 1966 5 Sheets-Sheet 2 DELAY vnessuae swrrcu 101 CLUTC H ACTUATOR swr-rcu SOLENO\D VALVE i IHHIH I Nov. 18, 1969 E. H. FERGUSON KNOCKOUT FOR FORGE MACHINE 5 Sheets-Sheet 3 Filed Dec. 29, 1966 $22 215 17% fiat Nov. 18, 1969 E. H. FERGUSON KNOCKOUT FOR FORGE MACHINE 5 Sheets-Sheet 4 Filed Dec. 29, 1966 Nov. 18, 1969 E. H. FERGUSON 'KNOCKOUT FOR FORGE MACHINE 5 Sheets-Sheet 5 Filed Dec. 29, 1966 Z Z l .Z% 6% ,J l 6 E M w 6 4 0 I III .W 0 1 0 3 w a 6% E mg United States Patent 3,478,566 KNOCKOUT FOR FORGE MACHINE Ellis H. Ferguson, Blue Island, 11]., assignor to Wyman- Gordon Company, Worcester, Mass., a corporation of Massachusetts Filed Dec. 29, 1966, Ser. No. 605,893 Int. Cl. B21d 45/ 0.0

U.S. 'Cl. 72-427 7 Claims ABSTRACT OF THE DISCLOSURE An ejector for a metal forging machine of the type having a fixed die, and a movable die actuated by toggle links. A cam portion on the end of the toggle links actuates a first ejector in the movable die. A fluid motor actuates a second ejector in the fixed die after the first ejector has ejected the workpiece from the movable die cavity.

This invention relates to improvements in machines for forming metal by the forging method. More particularly, the invention relates to a forging machine employing simplified mechanism for position ejection of a forged part at completion of the forging operation.

One problem which has plagued the metal forging industry for many years is that of preventing canting of a finished forging in a forging machine at the completion of the operation. This problem is highlighted, for example, in the performance of supplementary forging operations on a partly completed forging, for examplethe performance of an end forging operation on a crankshaft, or the like. Forging machines for performing such an operation customarily employ two grip dies which hold the forging workpiece during the end forging operation. When this operation is completed, the two grip dies open by relative movement in a horizontal plane to permit removal of the finished forging. As the grip dies open the forging is quite likely to stick in one or the other of the grip dies. On occasion this causes the forging to cant in the die and to strike the machine frame, resulting in a bent forging and a ruined part. To prevent this, skilled machine operators customarily shake the forging slightly with their tongs as the grip dies open, but even this is not a fool-proof prefentative measure.

It can be understood that this problem of sticking in forging grip dies becomes more acute as the speed of machine operation is increased. Increases inworkpiece sizes also tend to increase the problem and to cause more frequent damage to forgings. When the forging operation is partly or fully automated, as is increasingly the case, the operator is less able to cope with the sticking and canting problem, so that the danger of ruined parts is further increased.

It is possible to substantially solve the sticking problem by increasing the draft on the forging considerably and by cornmensurately increasing the draft in the cavities in the grip dies. This is undesirable, however, since it causes use of unnecessary material and increases eventual machining time in order to remove this excess material when the part is completed. Furthermore, the use of additional 9 draft requires deeper machining which removes the hardened material adjacent the surface and partly destroys the grain pattern which weakens the finished part. This is quite unacceptable in high strength parts, such as crankshafts, where the material flow and metal grain structure resulting largely from the forging operation is vital to the strength and longevity of the shaft.

Various mechanisms have been employed to properly dislodge finished forged parts from grip dies, including knockout mechanisms borrowed from the punch press art, for example. By and large such devices have been relative- "ice 1y complicated, expensive, and generally unsatisfactory. As far as is known, none of these mechanisms have met with any real success. As a result, the sticking problem has plagued the forging industry for many years without any satisfactory solution, until the advent of the present invention.

The present invention provides a very simple and foolproof solution to the problem through the use of apparatus employing largely the existing mechanism of a typical forging machine. The apparatus utilizes sequential events in the machine to actuate knockout pins which dislodge the finished forging first from the movable grip die of the forging machine and then subsequently from the fixed grip die of the machine as the dies open. This prevents any appreciable side motion of the finished part should the part tend to stick in the movable die as the dies open. It also provides for positive dislodging from the fixed die after the movable die has been displaced sufficiently to insure that the part will not be driven back against the movable die. The invention also contemplates imposing the dislodging force against the finished part simultaneously at axially spaced positions in the separate die halves, so that the part is dislodged from each of the dies in sequence in a direction perpendicular to the longitudinal axes of the dies.

Accordingly, it is an object of the present invention to provide improved knockout apparatus for mechanically dislodging a forged part from horizontally movable dies of a forging machine without damage to the part.

Another object of the invention is to provide improved knockout apparatus in a horizontal die forging machine for initially dislodging a finished forging from the movable die and subsequently dislodging the finished forging from the fixed die of the machine. More specifically, it is an object to actuate such an apparatus through employment of the existing mechanism of typical forging machines.

A further object of the invention is to provide improved knockout mechanism in a horizontal die forging machine to eject the finished forging from the movable die at a speed slightly less than the speed with which the movable die moves away from the fixed die upon completion of the forging operation to provide ejective without appreciable side motion.

An additional object of the invention is to provide improved knockout mechanism in a horizontal die forging machine to positively eject the finished forging from the stationary die in a manner to prevent contact of the finished forging with themovable die.

Still another object of the invention is to provide improved knockout mechanism in a horizontal die forging machine in which the dislodging force is applied simultaneously in axially spaced position along the finished forging to eject it in a direction perpendicular to the die axis. More particularly, it is an object to employ such mechanism sequentially in the two dies.

A specific object of the invention is to provide improved knockout mechanism for a forging machine employing horizontal grip dies in which the knockout apparatus employed with the movable grip die is actuated directly by the drive mechanism of the forging machine, while the knockout mechanism for the fixed grip die is operated through fluid pressure system of the machine through an event in the machine sequence occurring subsequent to withdrawal of the movable die.

Other objects, features, and advantages will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of a typical end forging machine employing grip dies incorporating improved knockout apparatus according to the present invention;

FIGURE 2 is a plan Sectional view of a typical crankshaft forging after a forging operation performed by the end forging machine of FIGURE 1;

FIGURE 3 is a top plan view of the end forging machine of FIGURE 1 showing the grip dies in the open position, with parts broken away for simplicity of presentation, and with a portion of the control system shown schematically;

FIGURE 4 is a longitudinal sectional view taken along line 44 of FIGURE 3, with parts removed;

FIGURE 5 is a transverse sectional view taken along line 55 of FIGURE 3;

FIGURE 6 is an enlarged fragmentary sectional view similar to FIGURE 5 but showing the grip dies of the machine in the closed position;

FIGURE 7 is a fragmentary sectional view taken along line 77 of FIGURE 6; and

FIGURE 8 is a fragmentary sectional view similar to FIGURE 7 but showing the mechanism with the movable grip die in the open position.

The forging knockout apparatus of the present invention is adapted for being applied to a typical horizontal die forging machine such as the end forging machine 10 shown in the various figures of the drawings. The machine is adapted for performing a forging operation on a metallic workpiece such as the steel crankshaft forging 12 of FIGURE 2.

The forging 12 is shown after the end forging operation, in which the forged end portion 14 was formed.

The remaining portions 16 of the forged crankshaft 12 were formed in previous forging operations which have no bearing on the present invention, except insofar as the contours of previously forged parts 16 of the crankshaft are utilized for holding the forging in the end forging machine 10 while the forged end 14 is being formed.

The end forging machine 10 incorporates a heavy machine frame 18 supporting a stationary die shoe 20 and a horizontally movable die shoe 22. The movable die shoe 22 is carried on a transverse grip slide 24 reciprocably mounted on the machine frame 18 by means of suitable ways (not shown). The stationary die shoe 20 is adapted for mounting a stationary grip die 26 and the movable die shoe 22 is adapted for mounting a suitable movable grip die 28. The grip dies 26 and 28 are formed with opposed

complementary die cavities

30 and 32, respectively, for closely and accurately gripping parts of the previously forged portion 16 of the crankshaft forging 12 when the grip dies are in the closed position as shown in FIG- URE 6.

It will be understood that the grip slide 24 and the movable grip die 28 are adapted for moving transversely on the machine bed as indicated by the double headed arrows 34 shown in FIGURES 3 and 6. The movable grip die is shiftable from an open position transversely spaced from the stationary grip die 26 as shown in FIGURE 3 l to a closed position abutting the stationary die as shown in FIGURE 6.

The end forging machine 10 includes a longitudinally movable header slide 36 adapted for carrying a suitable header die 38. The header slide 36 and the header 38 are movable in the longitudinal direction toward and away from the grip dies 26 and 28 as indicated by the double headed arrows 40 shown in FIGURES 3 and 4. The header slide is movable between a rest position as shown in FIGURES 3 and 4 and a forging position as indicated in FIGURE 2.

The grip slide 24 and the movable die 28 are moved beween open and closed position by means of drive linkage 42 which comprises a drive lever 44 and a pair of

toggle links

46 and 48. The inner ends of the three

links

44, 46, and 48, are pivotally connected to each other by a common pivot pin 50. The outer end of the toggle link 46 is pivotally connected to the stationary frame 18 by means of a pivot pin 52, and the outer end of the toggle link 48 is pivotally connected to the grip slide 24 by means of a pivot pin 54. The outer end of the drive link 44 is pivotally connected to suitable power actuated drive mechanism, including a crankshaft (not shown) for moving the drive link 44 generally in the direction indicated by the double headed arrow 56 shown in FIGURE 3. The crankshaft of the machine is adapted to make a complete 360 rotational movement with each machine cycle. When the machine is energized, the drive link 44 moves toward the right from the position shown in FIGURE 3 to straighten the toggle links 46 and 48 to close the movable grip die 28 to the position shown, in FIGURE 6, and then the drive link 44 moves back in the opposite direction to the position shown in FIGURE 3, breaking the toggle links to move the grip die back to the open position.

The drive mechanism of the machine is also suitably drivingly connected to the header slide 36 by means of a header crank drivingly associated with the drive shaft. When the machine is cycled to rotate the drive shaft 360, the header slide 36 is moved from the rest position shown in FIGURES 3 and 4 to the forging position shown in FIGURE 2, and then back to the rest position at the end of the cycle.

The end forging machine 10 incorporates a suitable clutch and a suitable brake which are adapted for being sequentially engaged. The clutch is engaged during approximately the first 280 of rota-tion of the drive shaft. During the remaining 80 of rotation of the drive shaft the clutch is disengaged and at 360 the brake engages to bring the drive shaft and the machines to rest at zero degree position at the end of each machine cycle.

In order to perform an end forging opera-tion on a workpiece such as the crankshaft 12 to form the forged end 14, the forging is positioned with a portion of the previously forged portion 16 loosely nested in the cavity 30 formed in the stationary forging die 26. The forging is typically red hot and is movably supported by suitable conveyor means (not shown). The power supply of the forging machine 10 is then made effective to cause the machine to operate through one forging cycle. During this forging cycle the grip slide 24 is first moved toward the forging until the two grip dies 26 and 28 are fully closed to accurately and firmly grip the forging in the

complementary cavities

30 and 32. Then the header slide 36 is moved forward to bring the header die 38 against the adjacent end of the workpiece to forge the metal to the desired configuration 14. The header slide then backs off, and as this occurs, the grip slide 24 carries the movable grip die 28 back to the open position. It will be understood that the machine parts and dimensions are such that the operations of the grip slide and the header slide are smoothly and continuously coordinated so that the grip dies are firmly closed before the header die 38 strikes the end of the workpiece and remain closed until the header die is retracted sufficiently to clear the forged end of the workpiece.

The end forging machine construction and operation described thus far are old and well known in the art.

As the grip dies 26 and 28 are open toward the end of the forging cycle it is necesasry that the forged part be dislodged from the cavities of the grip dies in a direction perpendicular to the header center line 58, or in other words with the forging axis parallel to the grip die center line 58, the finished forging can be removed from the machine without damage.

Often, however, the forging tends to stick in the cavity 30 of the stationary die 26 or the cavity 32 of the movable die 28. When sticking occurs, the finished forging frequently tends to cant, or in other words, its longitudinal axis 60 moves out of its parallel relationship with the grip die center line 58, usually in a generally horizontal plane. If the canting is severe enough the forging will strike the machine frame, resulting in a bent forging and a ruined part. In an efi'ort to prevent this canting as the grip dies open, skilled operators customarily shake the forging slightly with their handling tongs (not shown) as the grip dies open. Usually this manual shaking operation dislodges the forged parts, differences in operator skill, and the like, excessive canting cannot be consistently prevented, so that many forgings are ruined at the completion of an end forging operation. It will be understood that the scrapping of a forged part in this stage results in considerable loss of man hours and expensive machine time in addition to the material loss. The losses resulting from damaged parts have been absorbed as part of the overall manufacturing cost.

The present invention provides a very simple and positive solution for the sticking problem, employing largely the existing mechanism of typical forging machines. The knockout apparatus of this invention is provided in two coordinated segments, generally designated by the reference numeral 62 for the movable grip die 28, and fluid actuated knockout mechanism generally designated by the reference numeral 64 for the stationary grip die 26. The overall knockout apparatus, comprising the movable die knockout mechanism 62 and the stationary die knockout mechanism 64, is actuated in a coordinated fashion through existing elements of the end forging machine 10. The arrangement is such that on each cycle of the machine the knockout mechanism 62 is actuated first, and the knockout mechanism 64 is operated subsequently, in a manner to be described.

The movable die knockout mechanism 62 includes a pair of knockout pins '66, a cam pin 68, a knockout plate 70, and an actuating cam surface 72. The knockout pins 66 are slidably disposed in horizontal apertures 74 formed through the movable die 28 and communicating with the die shoe 22. The cam pin 68 is fixedly secured to the cam plate 70 at one end and is slidably disposed in an aperture 78 formed through a portion of the grip slide 24. A cam follower end 80 of the cam pin 68 is slidably engaged against the cam surface 72, which in turn is formed on the outer end of the toggle link 48.

The cam surface 72 of the toggle link 48 is of such a configuration that when the forging machine is at rest, the cam pin 68 and the cam plate 70 are driven inwardly, causing the inward ends of the knockout pins 66 to extend into the die cavity 32, as shown in FIGURES 3, 5, and 8, at which time the movable die 28 is in the open position. When the forging machine is actuated and the movable die moved to its closed position, as shown in FIGURES 6 and 7, the configuration of the cam surface 72 permits the knockout pins to be moved outwardly as the die closes on the workpiece, since the fall portion of the cam surface 72 is presented to the cam follower end 80 of the cam pin permitting the knockout pins to move the cam plate 70 and attached cam pin 68 outwardly.

The knockout mechanism 64 for the stationary die 26 includes a pair of knockout pins 82, a knockout plate 84, a knockout rod assembly 86, and a fluid servo 88. The knockout pins 82 are slidably disposed in horizontal apertures 90 formed through the stationary die 26 and communicating with the die cavity 30. The knockout plate 84 is shiftably disposed in an aperture 92 formed in the die shoe 20. The knockout rod assembly 86 includes a pair of rods 94 which are connected at their inward ends to the knockout plate 84 and extend through horizontal apertures 96 formed through a portion of the machine frame 18. The rods 94 are connected by adjustable securing means 98 to a piston rod 100 of the servo 88.

The servo 88 in the particular form shown comprises a pneumatic cylinder having a piston (not shown) attached to the piston rod 100. When the piston is in its retracted position, the knockout rod assembly 86 and the knockout plate 84 are moved outwardly to permit a workpiece to be nested in the cavity 30 of the stationary die 26 by moving the knockout pins 82 outwardly, as shown in FIGURE 6. When the piston is in its extended position, the knockout plate 84 and pins 82 are moved 6 inwardly to eject a workpiece from the cavity 30', as shown in FIGURE 5.

The pneumatic servo 88 is actuated through a fluid pressure system 102, which includes a fluid pressure conduit 104 connected to the outward end of the servo 88 and the fluid pressure conduit 106 connected to the inward end of the servo cylinder. The

conduits

104 and 106 are connected to two of the ports of a four-way, two position, solenoid operated control valve 108. A third port of the valve is connected to a fluid pressure supply line 110, and the fourth port is connected to an exhaust line 112.

The supply line 110 is also connected to a foot operated valve through a branch line 116. The valve 115, is, in turn, operatively connected through a Y-branch line 117 to the forge clutch 120 and to a conventional pressure responsive switch 122 containing time delay means and associated contacts (not shown). Another branch line 123 connects the valve 115 to the brake 124.

The solenoid valve 108 is operated by a control circuit 125 which contains the pressure operated switch 122, and, more specifically, time-delay contacts which are opened and closed by the switch. When the contacts are open, the valve 108 directs air to the line 106 and the piston rod 100 is retracted, retracting the knockout rod assembly 86. When the contacts are closed, the valve 108 directs air to line 104 and the knockout rod assembly 86 is extended.

In operation of the knockout mechanism of this invention, when the machine is at rest with the grip dies 26 and 28 open, the piston of the pneumatic servo 88 is withdrawn to withdraw the knockout rods 94 and attached plate 84, so that a workpiece to be forged on the machine 10 can be nested in the cavity 30 of the stationary die 26 by moving the knockout pins 82- outwardly against a negligible friction force. FIGURE 5 shows the condition before the nesting of a new workpiece. When a workpiece is nested in the stationary die cavity and the operator depresses the foot actuator 115 to engage clutch 120, which connects the crankshaft to the prime mover (not shown) to begin the aforementioned 360 rotation cycle of the shaft required for one forging cycle. The brake 124 is simultaneously disengaged. At the same time, air pressure is effective on the switch 122 to open contacts and reset the timing cycle. The knockout assembly 86 is retracted, of course.

At the same time, with the machine at rest and before the movable grip die 28 moves inwardly at the beginning of a cycle, the position of the toggle link 48, as shown in FIGURE 8, causes the knockout pins 66 to protrude into the cavity 32 of the movable die 28, since the rise portion of the cam surface 72 is adjacent the cam follower end 80 of the cam pin 68. As the machine crankshaft is rotated, the drive lever 44 is moved toward the toggle links 46 and 48 to cause them to straighten and to move the grip slide 24 and the movable die 28 toward closed position. As the toggle link 48 moves from the position shown in FIGURE 8 to the position shown in FIGURE 7, the cam surface 72 is rotated to provide a gap between the cam surface and the cam follower end 80 of the cam pin 68. As the machine crankshaft rotation proceeds, the movable grip die 28 moves into the closed position as shown in FIGURES 6 and 7, and as this occurs the workpiece moves the knockout pins 66 as well as the plate 70 and cam pin 68 outwardly as the part nests in the cavity 32 of the movable die. As shown in FIGURES 6 and 7, the dimensions of the parts are-such that the inward ends of the knockout pins 66 can be moved inwardly until they are flush with the die cavity surface before the cam follower end 80 engages the narrow portion of the cam surface 72, and, in fact, a slight play is provided to insure that the knockout pins are clear of the part when the dies are closed.

As the machine crankshaft continues its rotation, the header slide 36 and the header 38 are moved toward the grip dies and the gripped workpiece until the end forging operation has been completed to form the finished forged end 14 of the workpiece 12.

After the end forging operation, continued rotation of the machine crankshaft causes the header slide 36 and the header 38 to retract, and when they are clear of the part, the grip dies 26 and 28 begin to open by movement of the movable grip die 28 toward its open position. As soon as this happens, rotation of the toggle link 48 about the pivot pin 54 causes rotation of the cam surface 72 to urge the cam pin 68, knockout plate 70, and knockout pins 66 inwardly. Almost immediately, the knockout pins 66 are forced against the side of the finished workpiece causing it to be dislodged from the cavity 32 of the movable die 28. As the movable die moves farther outwardly, the knockout pins increase their protrusion into the die cavity to make certain the workpiece is positively ejected.

At this point in the machine cycle, the machine crankshaft has still not rotated to the 280 position. When it reaches the 280 position, the workpiece has been fully ejected from the movable die 28. At this point, a cam on the crankshaft operates a valve, which is eflective to cut off the pneumatic pressure to the machine clutch 120 and pressure switch 122, closing the timer contacts and opening valve 108 to direct air through line 104. The clutch 120 disengages (the crankshaft continues to rotate of its own inertia). The piston of the servo 88 moves inwardly, which in turn causes the knockout pins 82 to be forced into the die cavity 30 of the stationary die 26. Thus the workpiece is positively dislodged and ejected from the stationary die cavity 30 subsequent to ejection from the movable die cavity 32. The finished workpiece may then be readily removed from the machine and an unfinished workpiece substituted for the next machine cycle.

When air pressure to the switch 122 is cut off in the foregoing manner and the timer contacts close, a preset time period, calculated to be sufliciently long to complete ejection of the workpiece from the cavity 30, begins to run. After this time period has elapsed, the timer contacts automatically open, breaking the circuit to and causing the valve 108 to direct air under pressure to the servo 88 through the line 106. Consequently, the knockout rod assembly 86 is retracted.

Rctraction of the knockout rod assembly 86 takes place immediately subsequent to the rods 94 reaching full extension. This is still prior to the crankshaft reaching 360 of rotation. When the crankshaft has rotated to 360, a cam on the crankshaft is effective on a valve (not shown) to spill air from the brake 124, causing it to engage and stop the crankshaft. A machine cycle is completed.

It will be seen from this description that positive ejection force is applied through the knockout pins 66 and 82 in a direction perpendicular to the axis of the workpiece and perpendicular to the grip die axis 58, so that the part is ejected exactly perpendicular to the axis of the grip dies. This insures that the finished part is positively ejected in predetermined sequence from both die cavities and prevents any canting of the part as it is ejected.

In some instances, only one knockout pin 68 and one knockout pin 72 are required to perform the positive knockout operation. In other instanecs, however, it is advisable to use two knockout pins each so that force will be applied simultaneously at two longitudinally spaced positions along the workpiece to insure that the part is ejected exactly perpendicular to the die cavity axis. Three or more pins may be utilized if required, depending upon the size, weight, and configuration of the workpiece. Simutaneously actuation of the respective knockout pins 66 and 82 of the two grip dies is insured by employing a single knockout plate, 70, in the case of the movable die and 84 in the case of the stationary die, so that both knockout pins of each of the respective dies are moved exactly the same distance simultaneously.

The dimensions of the various parts of the movable die knockout mechanism 62 are arranged such that the inward ends of the knockout pins 66 are moved inwardly at a slower rate than the outward movement of the movable die 28 as it is retracted. This insures that while the workpiece is positively ejected from the cavity of the movable die, it is not knocked against the fixed die. However, the relative rates of movement are sufiiciently close that there is no significant tendency for the workpiece to be carried with the movable die during its outward travel. In other words, the workpiece remains substantially stationary while it is being ejected from the movable die.

Actuation of the knockout mechanism 64 of the fixed die does not occur until the movable die 28 has moved outwardly a sufiicient amount to insure that the finished workpiece will not be ejected from the fixed die into the movable die. It will be seen that this definite two-step sequence of ejection from the movable die and then from the fixed die is important, not only to positively insure that no sticking or canting of the workpiece occurs, but also to insure that the workpiece, first is not ejected from the movable die against the fixed die, and secondly, is not ejected from the fixed die against the movable die.

Although the invention is described utilizing particular machine events to actuate the movable die knockout mechanism 62 and then the fixed die knockout mechnism 64, it will be understood that other machine events could be utilized to the same effect as long as the required sequence is achieved. For example, actuation of the fixed die knockout mechanism could be triggered by actuation of the machine brake (not shown) which is used to stop the machine near the end of the cycle.

Although not absolutely necessary, it is very effective and expedient in connection with the present invention to actuate the movable die knockout die mechanism 62 mechanically and the fixed die knockout mechanism 64 by fluid pressure means.

Use of mechanical means for the movable die ejection system is particularly advantageous, since it provides very accurate control of the speed of ejection, that is, it permits positive movement of the knockout pins 66 inwardly at a speed only slightly less than the speed with which the movable die 28 retracts so that there is no significant tendency of the finished workpiece to follow the movable die. At the same time, there is no tendency to move the workpiece toward the fixed die.

In the case of the fixed die ejection system 64, fluid pressure ejection actuated means are quite expedient, since the ejection from the fixed die can be quite rapid, inasmuch as the fixed die ejection system need not be actuated until the movable die has achieved considerable clearance from the fixed die so that there is no danger of throwing the finished part against the movable die. In any event, the rapidity of ejection from the fixed die can be controlled through adjustment of a suitable pressure regulator.

Variations and modifications may be effected without departing from the scope of the novel concepts of the present invention.

What is desired to be claimed and secured by Letters Patent of the United States is:

1. In a metal forging machine having a fixed die and a movable die with opposed die cavities, wherein power means move said movable die toward and away from said fixed die through a gripping cycle, and control means for said power means, the improvement in apparatus for ejecting a workpiece from the dies, comprising:

(a) first mechanism for ejecting the workpiece from said movable die,

(b) second mechanism for ejecting the workpiece from said fixed die,

(c) means responsive to said power means for causing said mechanisms to eject said workpiece from said dies in a predetermined sequence in said gripping cycle,

((1) said second mechanism comprising fluid motor means arranged to extend ejector means into said fixed die cavity and eject said workpiece therefrom after the dies have closed on said workpiece and are in the opening portion of the cycle,

(e) said fluid motor means being energized to extend said ejector means into said fixed die cavity after said first mechanism has ejected said workpiece from the movable die cavity.

2. In a metal forging machine including a frame having a fixed die and a movable die mounted thereon, said dies having opposed die cavities, operation of actuator means causing a rotatable shaft to cycle movable die drive means, the improvement comprising:

(a) said movable die drive means including a drive lever drivingly connected at its inner end to said shaft and pivotally connected at its outer end to corresponding inner ends of first and second toggle links,

(b) said first toggle link being pivotally connected at its outer end to the frame,

(c) said second toggle link being pivotally connected at its outer end to said movable die,

(d) a cam surface formed on said outer end of said second toggle link,

(e) first ejector means in said movable die communicating with said movable die cavity and having cam follower means adapted to engage said cam surface,

('f) manipulation of said actuator means causing said shaft to rotate and move said drive lever to force the outer ends of said toggle links apart whereby said movable die is driven toward said fixed die and said cam surface is disposed to permit said ejector means to retract from said movable die cavity,

(g) continued rotation of said shaft causing said drive lever to retract and draw said toggle links toward each other whereby said movable die is drawn away from said fixed die and said cam follower means riding on said cam surface forces said ejector means into said movable die cavity,

(h) second ejector means in said fixed die communicating with said fixed die cavity,

(i) and said second ejector means being effective to eject said workpiece from said fixed die cavity after said first ejector means has ejected said workpiece from said movable die cavity.

3. The improvement in a metal forging machine of claim 2 further characterized in that:

(a) said cam surface has a predetermined configuration whereby said first ejector means forces the workpiece out of said movable die cavity at a lesser rate than the rate at which said movable die is moved away from said fixed die.

4. The improvement in a metal forging machine of claim 2 further characterized in that:

(a) said first ejector means comprises at least two ejector pins extending into said movable die cavity in parallel, spaced relationship,

(-b) knock-out plate means underlying said ejector pins,

(c) and a cam pin underlying said knock-out plate means, said cam pin having said cam follower means formed thereon.

5. The improvement in a metal forging machine of claim 3 further characterized in that:

(a) said second ejector means comprises at least two ejector pins extending into said die cavity in parallel, spaced relationship.

6. The improvement in a metal forging machine of claim 2 further characterized in that:

(a) said second ejector means comprises ejector pins extending through said fixed die into said fixed die cavity,

(b) and fluid :rnotor means effective to drive said ejector pins into said fixed die cavity when the shaft has rotated through a predetermined number of degrees, and after said first ejector means has ejected the workpiece from the movable die cavity.

7. The apparatus of claim 6 further characterized in that:

(a) said fluid motor means is energized by timer means after a predetermined time period subsequent to driving said pins into said fixed die cavity to retract said pins from said fixed die cavity.

References Cited UNITED STATES PATENTS CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner