US3605499A - Mechanism for ejecting workpieces from a die - Google Patents

Abstract

A KNOCKOUT MECHANISM FOR EJECTING WORKPIECES FROM A DIE WHICH COMPRISES A KNOCKOUT PIN SLIDABLY MOUNTED IN THE DIE AND SLIDABLY SUPPORTED IN A BORE IN THE FRAME THEREFOR, THE KNOCKOUT PIN COOPERATING WITH A SLEEVE MEMBER HAVING AT LEAST ONE ARM PIVOTALLY MOUNTED THERE-

ON AND COOPERATING WITH A FLANGE ON THE END OF THE FORWARD SECTION OF THE PIN SUCH THAT THE END OF THE ARM CAN PASS OVER AND GRIP THE FLANGE IN ORDER THAT THE SLEEVE MEMBER BE SLIDABLY RETRACTED WITH SAID KNOCKOUT PIN.

Description

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Filedl April 22, 1969 De D (m9 ,MATT RNEYS 17 1 NNN E N MECHANISM FOR EJECTING WORKPIECES FROM A DIE ww 911m Sept. zo, 1911 United States Patent 3,605,499 MECHANISM FOR EJECTING WORKPIECES FROM A DIE Anthony M. Putetti, Waterbury, Conn., assignor to Textron, Inc., Providence, R.I. Filed Apr. 22, 1969, Ser. No. 818,303 Int. Cl. B21d 45/00 U.S. Cl. 72-345 8 Claims ABSTRACT F THE DISCLOSURE A knockout mechanism for ejecting workpieces from a die which comprises a knockout pin slidably mounted in the die and slidably supported in a bore in the frame therefor, the knockout pin cooperating with a sleeve member having at least one arm pivotally mounted thereon and cooperating with a flange on the end of the forward section of the pin such that the end of the arm can pass over and grip the flange in order that the sleeve member be slidably retracted with said knockout pin.

This invention relates to a knockout mechanism for ejecting workpieces from a die and more particularly to a mechanism for ejecting blanks having relatively long shanks from a heading die.

Conventional knockout mechanisms for use in heading and extruding machines generally comprise a knockout pin acted upon by a knockout rod. The knockout pin is adapted to travel through a die so as to displace the shank of a formed workpiece therein. The knockout pin has a portion of larger diameter which is acted upon by the knockout rod in timed relation to the formation of the workpiece. When a punch is retracted after a forming blow on a workpiece in the die, the knockout rod is actuated by a connecting lever assembly so as to drive the knockout pin through the die, thus removing the formed workpiece therefrom. The knockout pin and knockout rod are then returned to their original positions by means of another workpiece being inserted into the die or by biasing means adapted to return the knockout pin and knockout rod after clearing the workpiece from the die.

A conventional knockout mechanism such as described above is fully set forth in U.S. Pat. No. 3,328,761. Such a conventional knockout mechanism performs satisfactorily in most applications, but difficulties Ihave been encountered when the shank of a workpiece is relatively long. The reason for this is that the section of the knockout pin passing through the die must also have a relatively long length in order to clear the die. Thus, when the relatively small-diameter section of the knockout pin is located in the bore of the frame, it is supported only at its ends when it receives the force of the pivoting lever. As a result of the sudden application of force, the forward section of the pin has a tendency to buckle and break, thereby jamming t-he machine and causing other consequential damage.

In view of the foregoing, it is an object of this invention to provide a new and improved knockout mechanism for ejecting workpieces having long shanks from a die.

Another object of the invention is to provide a new, improved, inexpensive and simple knockout mechanism for ejecting workpieces having long Shanks.

A further object of the invention is to provide a new, improved and effective support for a knockout pin in a knockout mechanism for a die so lthat the knockout pin will not buckle.

Still other objects and advantages of the invention will in part be obvious and will in part appear hereinafter.

Briefly stated, in one form thereof, this invention comprises a knockout pin having a long, small-diameter for ward section which passes through the die to eject a work piece therefrom. Formed integrally with the forward section of the knockout pin is a large-diameter plunger section which travels in first and second bores adjacent the die in the frame of the machine. Located in the first bore is a sleeve having at least one arm: pivotally mounted thereon, which arm is resiliently biased toward the forward section of the 'knockout pin. A flange is positioned on the forward section of the pin adjacent the plunger section and abuts the arm to move the sleeve as the knockout pin moves through the die. When the pin is retracted, the arm engages the flange on the pin and the sleeve is retracted by the pin. A shoulder at the end of the iirst bore allows the arm to disengage from said tlange. A knockout rod is slidably mounted in the second bore so that it may be acted upon by a lever to cooperate with the pin in a conventional manner.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference is had to thefollowing description, taken in conjunction with the accompanying drawings, in which FIG. l is a partial sectional view of a heading machine containing the knockout mechanism, showing the knockout pin as it is clearing the die;

FIG. 2 is an enlarged sectional view of a portion of the heading machine of FIG. 1, with the knockout pin in its fully retracted position;

FIG. 3 is an enlarged sectional view of a portion of FIG. 2, showing the support means for the knockout pin as it is being acted upon by the knockout rod;

FIG. 4 is a sectional view similar to FIG. 3, showing the arms on the support means for the knockout pin engaging a flange on the knockout pin so that the support means may be retracted;

FIG. 5 is a partial sectional View similar to FIGS. 3 and 4, showing the support means for the knockout pin as it is returning to its initial position; and

FIG. 6 is a sectional view taken along line 6---6` of FIG. 5.

There is illustrated in FIG. l a part of a heading machine in which the knockout mechanism of this invention can be used. Although shown with a heading machine, it should be understood that this invention can be used with any machine in which it is required to clear a die of long-shanked workpieces.

Positioned in frame 10 of a machine, such as a header or the like, is a bearing surface 11 on which a gate 12 reciprocates. Mounted at the end of gate 12 is a punch holder 13 which carries a punch 14. The punch 14 is positioned to operate on a workpiece 1S located in a die 16 so as to form a head thereon. The gate 12 is reciprocated by means of a pitman 17 pivotally connected thereto. The pitman 17 rides on a crank 18 of a crankshaft 19, the crankshaft 19 reciprocates gate 12 and causes punch 14 to act upon the workpiece.

A workpiece is transferred to the die 16 by transfer mechanism generally indicated at 20. Such transfer mechanisms need not be explained in detail since they are well known in the art and, in structure, do not form a part of this invention. The die 16 is positioned in frame 10 by means of a sleeve 21. Located in back of and supporting the die 16 are backing plates 22 and 23 having bores 24 and 25 therein to allow for the passage of a knockout pin 26. Adjacent to and cooperating with pin 26 is a knockout rod 27 which rides in a bore 28 in the frame of the machine. The rod 27 is forced forward by the action of a lever 29 pivotally connected to the frame of the machine by a pin 30. The lever 29 is pivoted about the pin 30l by a connecting rod 31, so that the head of the lever 29 abuts a stop 32 in its retracted position. The stop 324 is threadably engaged in a plate 33 so that it can be adjusted for control of the travel of lever 29. Further, the lever 29 is acted upon by a set of levers and connecting mechanism (not shown), so that knockout pin 26 will be forced through the die 16 when gate 12 is in a retracted position. These other levers and connecting mechanism are disclosed in U.S. Pat. No. 3,238,761.

After a finished workpiece has been ejected from the die, a new workpiece is brought before the die by the transfer mechanism 20. As the gate 12 moves forward to force the new workpiece into the die, lever 29 is pivoted against the stop 32. The workpiece being forced into the die then returns the knockout pin to its original position, as shownin FIG. 2.

Referring now to FIGS. 2-6, it can be seen that the knockout pin comprises a long, small-diameter forward section 34 having substantially the diameter of the Workpiece so that it can pass through bore 24. lFormed on the section 34 is a large-diameter plunger section 35 which slides in bores 25 and 28 formed in the bearing surfaces in the frame of the machine. A flange 35a is formed on forward section 34 adjacent plunger section 35. Bore 2-5 extends through the backing plate 23 into a bearing surface in the frame of the machine. Support means 36 closely lits in bore 25 and can easily slide therethrough. Adjacent the bore 25, there is formed in the bearing surfaces bore 28 having a smaller diameter than bore 25 so as to deilne a shoulder 38 which limits the movement of support means 36. The shoulder 38 is formed at a position in the bearing surfaces such that when pin 26 is in the fully retracted position shown in FIG. 2, the support means 36 will abut the shoulder and substantially support the central part of the forward section 34 of pin 26. This positioning of the support means effectively prevents the forward section of pin 26 from buckling when acted upon by lever 29 through knockout rod 27. The bores 25 and 28 may be formed in a single bearing surface or in a number of bearing surfaces. The plunger section 35 closely ts in bore 28 and slides therein. The bore 28 extends through the frame of the machine so that rod 27 can slide therethrough and cooperate with the plunger section of the pin 26. The knockout rod 27 is preferably of the same diameter as the plunger section of the pin, although it may be of a somewhat larger or smaller diameter. If the diameters of plunger section 35 and rod 27 differ, the diameter of bore 28 will have to be adjusted to enable both of these parts to slide therethrough.

The support means 36 comprises a sleeve member 39 which tits closely about the forward section 34 of the pin to provide good support thereto while permitting relative movement between the section 34 and sleeve member 39. The sleeve member 39 has two longitudinal grooves 40 and v41 therein, substantially diagonally opposite each other, in which two arms 42 and 43` are pivotally mounted by means of pins 44 and 45, respectively. In the support means of this invention there need be only one arm. However, it is preferred to have two arms substantially opposite each other so that the ends thereof can more positively grip ilange 35a. Further, more than two arms arranged in similar longitudinal grooves, may be used with the support means. Projections 42a and 43a are formed at the ends of the arms to permit the arms to grip flange 35a. It should be understood that these projections are not necessary since the arms may be curved toward each other in a manner whereby the use of projections would not be necessary.

The arms are biased toward each other by means of two O-rings 46 and 47 constructed of resilient material such as rubber or a plastic. Although it is possible to use only one O-ring, two such rings are preferred, in order to bias the arms tightly toward each other to llrmly grip flange 35a. The O-rings 46 and 47 are positioned in circumferential grooves 48 and 49, respectively, in the sleeve so that they will not interfere with the travel of the sleeve. Any other type of resilient means may be used to bias the arms toward each other, such as a spring in the form of an O-ring, if such means do not interfere with the movement of the sleeve in the bore 25.

In operation, as the lever 29` moves in the direction of the arrow '50, FIG. 2, it will force the rod 27 and the pin 26- to the left, as shown in FIG. 3. As soon as the ilange 35a abuts the projections 42a and 43a at the ends of arms 42 and 43, respectively, the sleeve member 39 will be forced forward, as shown in FIG. 3.

When the sleeve 39 reaches the end of bore 25 and abuts the backing plate 22, the pin 26 will continue to move forward under pressure from rod 27, such that the llange 35a passes by the projections 42a and 43a, as illustrated in FIG. l. When a new workpiece is inserted into the die, the pin 26 will be forced backward, carrying sleeve 39 with it since the projections 42a and 43a will tightly grip flange 35a, as shown in FIG. 5. When the sleeve member 39 reaches shoulder 38, it will be unable to move further. However, the pin 26 will continue to be forced backward by the workpiece. This results in the opening of arms 42 and 43 to release the flange 35a and pin 26 will continue to move until it is in the position illustrated in FIG. 2. The knockout cycle will then be repeated.

The resiliently-biased arms 42 and 43 provide a simple mechanism for returning the sleeve member 39 to its initial position, Another advantage of the arms 42` and 43 is that the sleeve member 39 supports the forward section of the pin adjacent the plunger section as it returns to its initial position. Since the plunger section 35 does not lit closely in the bore 25, this support of the sleeve prevents the forward section of the pin from bending due to the weight of the plunger section. Therefore, plunger section 35 of the pin 26 will be aligned with bore 28 and easily pass into the bore as the pin 26 is retracted.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are etllciently attained and since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It should also be understood that the following claims are intended to cover all the generic and specillc features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What I claim is:

1. In a heading machine including a frame, a shaft rotatably mounted in said frame, means for rotating said shaft, a die bed mounted on the frame, a die mounted on the die bed, a gate reciprocally mounted on said frame for operation by the shaft, the gate carrying a tool to cooperate with the die, a knockout pin slidably mounted in the die and in first and second bores in said frame wherein said first bore lies adjacent to said die, a knockout rod slidably mounted in said second bore in said frame for cooperating with said knockout pin, and a lever pivotally positioned `on said frame and engaging an end of said knockout rod to advance said rod against said knockout pin, such that said pin will pass through the die to clear said die, the improvement comprising a knockout pin having a long small-diameter forward section and a largediameter plunger section with a flange located on the end of the forward section adjacent the plunger section and a sleeve member having at least one arm pivotally mounted thereon, said arm extending toward said flange and resiliently biased toward the pin, whereby the end of the arm can pass over and grip said flange so that said sleeve member can be slidably retracted with said knockout pin.

2. In a heading machine according to claim 1, further including at least one O-ring constructed of resilient material positioned on said sleeve member to resiliently bias the arm toward the pin without interfering with the travel of said sleeve in said first bore.

3. In a heading machine according to claim 2, a shoulder positioned between said rst and second bores in said frame such that the travel of said sleeve is arrested by said shoulder to disengage the arm on said sleeve from the ange on said knockout pin when said pin is retracted from said die.

4. In a heading machine according to claim 1, wherein two arms are pivotally mounted directly opposite to each other on said sleeve member and extend toward said flange, and wherein said arms are resiliently biased toward each other.

5. A knockout mechanism for ejecting workpieces having long shanks from a die positioned in a frame by means of a knockout pin acted upon by actuating means, comprising a knockout pin having a long small-diameter forward section and a large-diameter plunger section which is slidably mounted in said die and in first and second bores in said frame, wherein said rst bore lies adjacent to said die, a sleeve member closely tting over the forward section of said knockout pin and capable of moving within said rst bore when acted upon by the pin as the pin advances to clear the die, a ange located on the end of the for-ward section of the pin adjacent the plunger section and at least one arm pivotally mounted on said sleeve member extending toward said flange and resiliently biased toward the pin, whereby said arm can pass over and grip said ange so that said sleeve member can be slidably retracted with said pin.

6. The knockout mechanism of claim 5, wherein at least one O-ring constructed of resilient material is l0- cated on said sleeve member to resiliently bias the arm toward the pin witohut interfering with the travel o'f said sleeve in said rst bore.

7. The knockout mechanism of claim 6, wherein a shoulder is positioned between said rst and second bores in said frame to arrest the travel of said sleeve member to disengage the arm on said sleeve member from the flange on said knockout pin when said pin is retracted from said die.

8. The knockout mechanism of claim 45, wherein two arms are pivotally mounted on said sleeve member directly opposite each other and extending toward the ange, and wherein said arms are resiliently biased toward each other.

References Cited UNITED STATES PATENTS 1,856,440 5/1932 Spire 7?;-345 3,238,761 3/1966 Hoyt M 72-345 3,431,825 3/1969 Crawley 92--165 RICHARD J. HERBST, Primary Examiner gg C UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,605 ,N99 Dated September' 2O 1971 i Inventor(g) Anthony M Putett It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown beluw:

Column l, line 23 of the specification, change "3,328,761" to 3,238,761.

Claim 6, line U, change "witohut" to w1thout.

Signed und sealed Ehs 18th day of April 1972.

(SEAL) AI test VIT/'HALTE I`-I.FLEI?CIUYTR,JR. ROBERT GOTTSCI-IALK "1 tbesgng; Officer Commissioner of' Pa tents

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