US2749610A - Method and machine for making shackles - Google Patents

Description

June 12, 1956 F. J. WELSCH 2,749,610

METHOD AND MACHINE FOR MAKING SHACKLES Filed Sept. 20, 1952 2 Sheets-Sheet 1 N. 6 INVENTOR.

[%d mq W ATT R/IE Y5 0- FRANKJ. WELSCH June 12, 1956 F. J. WELSCH METHOD AND MACHINE FOR MAKING SHACKLES Filed Sept. 20, 1952 2 Sheets-Sheet 2 VI WVIIIIIIAQWVIIIIQMJVI 10 INVENTOR.

FZ ANK J WEL SCH M wZZwg A TTOH/YE v5 United States Patent 2,749,610 METHOD AND MACHINE FOR MAKING SHACKLES Frank John Welsch, Campbell, Calif. Application September 20, 1952, Serial No. 310,645 7 Claims. (Cl. 29-545) The present invention relates to forging, and pertains more particularly to a machine and method for use in the forging of chain shackles.

In naval and marine work, large quantities of shackles are employed for use on the numerous types of chains used in the securing and hoisting of various equipment and commodities aboard ship. The making of the shackles for securing the ends of such chains has been the subject of a considerable amount of development, and in the past several attempts have been made to improve the usually slow and tedious process of manufacturing these shackles.

The present invention contemplates the provision of an improved machine for the manufacturing of chain shackles.

The invention also provides an improved method for the making of chain shackles.

It is also the purpose of the present invention to provide a machine for the manufacture of chain shackles whereby successive steps of their manufacture can be carried on in a simple and easy manner and with the use of a minimum amount of power and equipment.

A further object of the invention is to provide a machine for the manufacture of chain shackles which will permit manufacture of the shackles at a minimum cost and with a maximum degree of uniformity.

These and other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, wherein:

Fig. 1 is a fragmentary perspective view showing the punch and die zone of a forging press with punches and dies embodying the present invention and capable of operating in accordance with the method of the present invention, portions of associated parts of the press also being shown.

Fig. 2 is an enlarged perspective view of a shackle made in accordance with the method of the present invention by mechanism such as that shown in Fig. 1.

Fig. 3 is a perspective view of a shackle pin for use with the shackle shown in Fig. 2.

Fig. 4 is a fragmentary horizontal sectional view taken as on line 4-4 of Fig. 7, but showing the dies in shut, or closed position, and the ram, with the piercing die mounted therein, advanced.

Fig. 5 is a fragmentary horizontal sectional view taken along line 5-5 of Fig. 7.

Fig. 6 is a fragmentary horizontal sectional'view taken along line 6--6 of Fig. 7, a portion of the ram, with a forming punch mounted therein, being shown in advanced position in broken lines.

Fig. 7 is a fragmentary vertical sectional view taken on a plane defined by the axes of the three punches shown in Fig. 1. p

' Fig. 8 is a side elevational view of a length of rod used for making a shackle blank.

Fig. 9 is a side elevationalview of the shackle blank formed from the rod shown in Fig. 8.

Fig. 10 is a perspective View of the blank shown in Fig. 9 after a-lug forming operation has been completed thereon.

Referring to the drawings, the machine A shown in Fig. 1, for the making of shackles B (Fig. 2), is a gen-1 erally conventional two stage horizontalforging press.

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The machine A has a pair of laterally converging die holders 10, 10 with a pair of similar but opposite die blocks 11, 11 mounted thereon. The die holders 10, 10 are arranged to move the die blocks 11, 11 into closely abutting relationship, and to dwell with the dies held in such closed position for a predetermined length of time during each operating cycle of the machine A.

Forming punches 12, 12 and a piercing punch 13 are mounted on a punch block 14 which is secured by bolts 15 in a conventional manner to the ram 17 of themachine A. During each cycle of operation of the machine A, after the dies 11, 11 have been moved to their closed position, the punches 12, 12 and 13 will be advanced and then retracted before the dies 11, 11 again are moved to their open position as shown in Fig. 1.

Each die block 11 has a horizontal U-shaped lower die cavity 18 therein closely to receive a U-shaped work piece 19 (Fig. 9) therein. A recess 20 is provided at the bight portion of each U-shaped lower cavity 18 to provide clearance for the nose portion of a con-- ventional pair of tongs (not shown) used for handling the blanks 19 when inserting them in the cavities 18 and removing them therefrom.

Deepened portions 21, 21 are provided one in each leg of the die cavities 18, 18 for forming enlarged lugs 22 and 23 (Fig. 10) on the ends of the legs 19a and 19b, respectively, of each work piece 19. The work piece with the lugs 22 and 23 formed thereon will be referred to as the shackle blank 26. The deepened cavity portions 21, 21 are of generally semi-circular configuration as shown in Fig. 6.

The forward or right hand ends of the forming punches 12, 12 (Figs. 1, S and 7) are of a concavity, and the punches are of a length, relative to the stroke of the ram 17, to complement the curvature of the deepened portions 21, 21 of the U-shaped die cavitives 18, 18 when the die blocks 11, 11 are in their closed position, and the ram 17 is fully advanced as shown in broken lines in Fig. 6.

Thus, upon the advancement of the forming punches into the left hand ends of the legs of the U-shaped die cavity 18, the material of the legs 19a and 19b of the U-shaped blank 19 which extend beyond the deepened cavity portions 21, 21 is forced back into the deepened cavity portions 21, 21. This operation forms lugs 22 and 23 on the ends of the legs 24 and 25, respectively, and changes the work piece 19 to the formed shackle blank 26 (Fig. 10).

It will be noted in Fig. 9 that the other leg 1% of the U-shaped blank 19 is slightly shorter than the other leg 19b thereof. The respective lengths of the legs 19a and 19b of the blank 19 are such that the lug 22 (Fig. 10) formed on the shorter leg by the forward stroke of the forming punches 12, 12 will be slightly smaller than the lug 23 formed on the longer leg 1%. The machine A completes its first cycle of operation by retracting the ram 17, by withdrawing the punches 12, 12 and 13, and then separating the die blocks 11, 11 to the position thereof shown in Fig. 1.

Upper die cavities 28, 28 (Fig. 1) each comprise a pair of horizontal semi-cylindrical portions 29, 29, one of said cavities extending lengthwise of each die block 11. Three deepened cavity portions 30, 31 and 32 are formed coaxially of each of said cavity portions 29, 29. These cavities 28, 28 are complementary to each other when the die blocks 11, 11 are in their closed position as shown in Fig. 4. The deepened cavity portions 30, 31 and 32 are of a size, and are spaced apart, to receive the lugs 22 and 23 of the formed shackle blank 26, as shown in Fig. 10, when the shackle blank 26 is positioned in either of the two broken line positions 2611 or 26b shown in Fig. 7.

The piercing punch 13 is mounted on the block 14 in position to align axially with the complementary semieylindrical recesses 29, 29 when the die blocks 11, 11 are in their closed position, as shown in Fig. 4-. The piercing punch 13 has the base or lefthand portion 33 thereof (Figs. 2 and 7) of a diameter slightly less than that of the larger shank portion 33a of the shackle pin C shown in Fig. 2. This larger diameter portion 33 of the piercing punch 13 is of a length to extend beyond the first enlarged die cavity portion 30 when the ram 17 is fully advanced as shown in Fig. 4. The outer or right hand portion 34 of the piercing punch 13 is reduced to a diameter slightly less than that of the threaded end portion 34a of the shackle pin C, and is of a length to extend beyond the central deepened cavity portion 31 when the ram is fully advanced. The intermediate portion 35 of the punch lying between the larger diameter base portion 33 and the smaller diameter outer portion 34 is tapered from one of said diameters to the other. Usual clearances are provided between the piercing punch 13 and the die blocks 11, 11.

The operation of the herein disclosed mechanism, and the method employed in the making of the shackles B (Fig. 2) is as follows:

A plurality of straight lengths 37 (Fig. 8) of round bar stock of suitable metal are cut off and are bent to form the work piece 19 shown in Fig. 9 by conventional bending dies, not shown. One leg 19a of the U-shaped work piece 19 is slightly shorter than the other leg 19b thereof, as mentioned previously herein. A plurality of the U-shaped work pieces 19 are heated to a desired forging temperature by a conventional furnace or other heating means, not shown. The heated work pieces 19 then are seized at their bights, one at a time, by an operator using conventional tongs. not shown, and are placed in one of the lower U-shaped cavities 121 in the position indicated by dash-two-dot lines in Fig. 7. The recesses 20, 20 at the right hand end (Fig. 7) of the cavities 18, 18 provide clearance for the nose of the tongs when the dies are moved to their closed position as shown in Fig. 6. The machine A then is operated in a usual manner, first to close the die blocks 11, 11 to grip the blank 19 there between, and then to advance the ram 17 to move the forming punches 12, 12 to the position indicated in dashone-dot lines in Fig. 6. This action of the forming punches forces the end portions of the legs 1% and 19b of the blank 19 which extend beyond the deepened cavity portions 21, 21 back into these deepened cavity portions.

This action by the forming punches 12, 12 forms the lugs 22 and 23 on the shackle blank 26 (Fig. The operator then, by means of usual tongs, removes the shackle blank 26 thus formed from the lower die cavity 18 and places it, still at forging temperature, in the upper die cavity 28 in the position indicated by the right hand dash-three-dot line 26a in Fig. 7. In this position of the shackle blank 26, the smaller lug 22, which was formed on the shorter leg 19a of the blank 19, will be positioned in the central recessed portion 31 of the upper cavity 28, and the other or larger lug 23 will be positioned in the right hand recessed cavity portion 32. The machine A then is operated through another cycle. During this second cycle of operation, after the die blocks 11, 11 have been moved to their closed position, the ram 17 is operated to advance the piercing punch 13 to the position shown in Fig. 4, thereby punching a hole of the diameter of the reduced outer or right hand end portion 34 of the piercing punch 13 in the smaller or left hand lug 22 of the shackle blank 26.

Upon completion of this second cycle of operation of the machine A, with the ram 17 retracted to the position thereof shown in Fig. 7 and the die blocks 11, 11 separated as shown in Fig. l, the shackle blank 26, with its left hand lug 22 pierced, is removed from the right hand pair of upper die recesses 31 and 32, and is. replaced in the die with the pierced smaller lug 22 in the left hand recess 30 and the larger lug 23 in the central recess 31 as shown by the dash-two-dot line 26b in Fig. 7. At this stage of operation, a fresh U-shaped blank 19 may be placed at forging temperature in one of the lower U- shaped cavities 18. The press then is operated through a third cycle (with respect to the blank 26 in the recesses 31 and 32) to close the die blocks 11, 11 and to advance the ram 17.

As the piercing punch 13 again is advanced to the position shown in Fig. 4, with the shackle blank in the left hand position 2611 of Fig. 7, it will be noted that the tapered intermediate portion 35 and a portion of the larger diameter base portion 33 of the piercing punch 13 will be forced through the hole made in the smaller lug 22 by the preceding stroke of the ram 17 when the shackle blank 26 was in the right hand position 2611 of Fig. 7. This action of the tapered punch 13 enlarges the hole in the smaller lug 22 and expands the surrounding metal of the lug 22 radially outwardly rela tive to the punch axis, thereby causing the lug 22 to fill the recesses 30, 36. By this action the smaller lug 22 is expanded, as shown in the completed shackle B in Fig. 2, to the same external size as the larger lug 23. During this same third stroke of the ram 17, the piercing punch 13 also punches a hole in the right hand lug 23 of the shackle blank 26, which lug is at that time positioned in the central die recesses 31, 31.

Each slug, not shown, punched from the lugs 22 and 23 by successive strokes of the punch 13 is carried beyond its respective lug and into the opening formed by the channels 29, 29 as the punch 1.3 completes each punching stroke. These slugs usually drop by gravity out of the channels 29, 29 when the dies 11, 11 are separated upon the completion of an operative cycle of the press. Should they tend to hang up in the cavities 23, 28 however, they may be easily freed by tapping them with the tongs or other tool to cause them to drop clear of the dies.

This third cycle of operation of the machine A completes the shackle except for a usual final tumbling operation, the reaming of the larger hole 38 (Fig. 2) and the threading of the smaller hole 39 to receive the conventional shackle pin C, all in a usual manner.

In the event that extremely large runs of a particular size of shackle are contemplated, it is possible to expedite the operation somewhat by making the lower portion of the die blocks 11, 11 having the U-shaped cavities 18, 18 therein separately, and by performing the initial lugforming operation in a separate press, having separate forming punches similar to the punches 12, 12. When this latter procedure is followed, it is desirable to have the presses located closely adjacent each other so that blanks may be processed from the work piece heating means to the lug-forming press and thence to the punching or piercing press without intermediate handling or heating of the work pieces or blanks.

While I have illustrated and described a preferred embodiment of the present invention, it will be understood however, that various changes and modifications may be made in the details thereof without departing from the spirit and scope of the invention as set forth in the appended claims.

Having thus described the invention, What I claim as new and desire to protect by Letters Patent is defined in the following claims.

I claim:

1. In a forging press having a pair of die blocks movable toward and away from each other and having a ram movable at right angles to the direction of die block movement; a plurality of aligned, lug receiving cavities in each die block, the cavities in one die block being complementary to those in the other, said cavities being formed and arranged to receive lugs on a shackle blank in either of two selected positions therein, said die blocks having an opening formed therein to extend through a first and a second of the aligned lug receiving cavities, and a piercing punch mounted on the ram to enter said opening, said punch being of a length to project, on an operative movement of the ram, through said first and second cavities, the portion of the punch passing through said second cavity being of a size to punch a hole of predetermined size in the lug of a shackle blank therein, and the portion of the punch passing through said first cavity being of a larger diameter than the portion passing through said second cavity.

2. The method of forming a shackle blank with holes of different diameter in the end lugs thereof, which comprises bending a straight length of bar stock to form a Work piece of U-shape to have one leg thereof longer by a predetermined amount than the other leg, forming the end portions of the legs into lugs .to bring the legs to equal length, thereby forming the lug on the longer leg of the work piece of a size larger than the lug on the shorter leg, forcing the small end of a punch having a smaller diameter punching portion and a larger diameter expanding portion through the smaller of said lugs to pierce it with a hole axially directed toward the center of the larger lug, moving the work piece closer to the punch and advancing the punch axially through the hole in the smaller lug to pass the larger diameter portion of the punch through the hole formed in the smaller lug to expand said smaller lug and to increase the diameter of the hole therein, the punch being advanced a sufficient distance to pass the small end of the punch through the larger lug to pierce it.

3. A mechanism for making a shackle blank from a U-shaped work piece having laterally opposite lugs of different size formed on the ends of the legs thereof, said mechanism comprising; means for holding the lugs in a first predetermined position, a punch having a punching end portion of predetermined diameter and having an expanding portion of larger diameter spaced rearwardly therefrom, means operable to advance said punch along an axial path centrally intersecting the lugs when gripped in said first position to punch a hole in the smaller of said lugs, and means for gripping the lugs in a second predetermined position closer to the punch and with the hole punched in said one lug aligned axially with the punch, said punch advancing means being again operable axially to advance the punch along said path with the lugs gripped in their second adjusted position, thereby passing said punch through the hole punched in the smaller lug a distance sufficient to pass the enlarged punch portion through said hole thereby enlarging the hole and expanding the smaller lug, and in the same stroke passing the punching portion of the punch through the larger lug to punch a hole therein.

4. In a forging press having a pair of die blocks movable between open and closed position, a plurality of aligned, lug receiving cavities in each die block, said aligned cavities in one die block being complementary to those in the other, the aligned cavities in each die block being spaced apart by the distance separating a pair of lugs formed on the legs of a U-shaped work piece, complementary semicircular channels extending centrally through a first and a second of said aligned lug receiving cavities, and a piercing and expanding punch mounted to enter the semi-circular channels in a closed position of the die blocks, said piercing punch being of a length to project through a first and a second of said aligned cavities, the portion of the punch passing through said second cavity being of a size to punch a hole of predetermined size in the lug of a shackle blank therein, and the portion of the punch passing through said first cavity being of larger diameter than the punch portion passing through said second cavity, a portion of the punch located between said two punch portions being tapered to exert an expanding force on a lug in said first cavity in passing through a pre-punched hole in such latter lug.

5. In a forging press having a pair of die blocks movable between open and closed condition, and having a ram movable at right angles to the movement of the die blocks; each die block having three lug receiving cavities therein aligned in the direction of ram movement and spaced apart to receive, in either of two positions, the lugs of a work piece with a pair of lugs formed thereon, each die block having a straight punch receiving cavity extending centrally of said lug receiving cavities in the direction of ram movement, the straight cavity portion extending through the first lug receiving cavity toward the ram being of larger diameter than the portion thereof extending through other lug receiving cavities, and a piercing punch mounted on the ram to enter said straight cavity during an operative stroke of the ram to pass within the straight cavity through two of the three lug receiving cavities, the portion of the punch passing through the second lug receiving cavity from the ram being of smaller diameter than the punch portion passing through said first lug receiving cavity, thereby to prepunch a hole in a first lug positioned in the second of said two lug receiving cavities in one position of the work piece, and to pass through and enlarge the prepunched hole in said first lug, and to punch a hole in the other of said lugs in a second position of said work piece in said lug receiving cavities.

6. In a forging press having die holders movable toward and away from each other, and having a ram movable at right angles to the direction of die holder movement; a pair of die blocks mounted on the die holders to move from open to shut position, each die block having three centrally aligned lug receiving cavities therein, said cavities being complementary to each other in a shut condition of the die blocks, said cavities being spaced apart to receive, in either a first or a second predetermined position, the lugs of a U-shaped shackle blank having lugs on the legs thereof, said die blocks having a punch receiving opening therein extending, in the shut condition of the die blocks, centrally through a first and a second of said lug receiving cavities, and a piercing punch mounted to enter said punch receiving opening during an operative stroke of the ram to pass in sequence through said first and second lug receiving cavities, thereby, in a first of said predetermined positions of the work piece, to punch a hole in a first lug positioned in the second of said lug receiving cavities, and, in a second predetermined position of the work piece, with the first lug positioned in the first of said lug receiving cavities, to pass through the hole punched in the first lug in said first predetermined position of the work piece, and to punch a hole in the second of said lugs positioned in the second of said lug receiving cavities.

7. An arrangement according to claim 6 wherein the punch is enlarged at a point between the first and second lug receiving cavities in an advanced position of the punch to expand said first lug in passing through the hole therein with the work piece positioned in said second predetermined position thereof.

References Cited in the file of this patent UNITED STATES PATENTS 140,422 Krementz July 1, 1873 228,907 Lanz June 15, 1880 350,859 Anderson Oct. 12, 1886 399,903 Kennedy Mar. 19, 1889 535,301 Smith Mar. 5, 1895 1,070,121 Ecseghy Aug. 12, 1913 1,250,411 Amiot Dec. 18, 1917 1,313,949 Mountford Aug. 26, 1919 1,756,376 Moore Apr. 29, 1930 1,984,350 Halsey Dec. 11, 1934 1,997,871 Miller Apr. 16, 1935 2,621,344 Friedman Dec. 16, 1952

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