US2737838A - Tongs - Google Patents

Description

March 13, 1956 2,73 7,838

A. B. SEGUR TONGS Filed Dec. 24, 1952 6 Sheets-Sheet l 50 affm/vaga A B. SEGUR March 13, 1956 TONGS 6 Sheets-Sheet 2 Filed Dec. 24, 1952 March 13, 1956 Filed Dec. 24, 1952 A. B. SEGUR TONGS 6 Sheets-Sheet 5 March 13, 1956 A. B. SEGUR 2,737,838

TONGS Filed Dec. 24, 1952 6 Sheets-Sheet 4 A. B. SEGUR March 13, 1956 TONGS 6 Sheets-Sheet 5 Filed Dec. 24, 1952 ltc"zza 4 4" 79m/ Z7/Cvwzqcy;

March 13, 1956 A. B. SEGUR 2,737,838

TONGS Filed Dec. 24, 1952 6 Sheets-Sheet 6 N1 \3 a s;

United States Patent 1 Claim. (CI. 81-51) My invention pertains to a metal forging system and method particularly adapted for the hot forging of metals, although some features of the invention may be utilized in the cold forging of metals and certain aspects of the invention are of even more general application.

An object of my invention is to utilize manpower and machinery more effectively, increase output, reduce cost, and secure more uniform and improved results.

Another object of my invention is to increase efficiency through the utilization of a new principle.

Another object of my invention is'to accomplish the foregoing objects without materially increasing capital investment.

In the drawings:

Fig. 1 is a top plan View of a layout embodying a preferred form of my invention;

Fig. 2 is a perspective view of a workpiece and tongs for grasping same;

Pig. 3 is a front elevational view of a workpiece magazine, and feeding mechanism therefor;

Fig. 4 is a side view of the upper part of Fig. 3;

Fig. 5 is a partial view showing a detail and is taken on the line 5-5 of Fig. 4;

Fig. 6 is a front elevational view of a portion of the furnace and a locating grill attached thereto;

Fig. 7 is a horizontal sectional view taken on the line 7-7 of Fig. 6, showing the table projecting from the front of the furnace and the horizontal guides afiixed to the table;

Fig. 8 is a partial vertical section taken on the line S8 of Fig. 6 and indicates the manner in which a tool is guided into engagement with the end of a workpiece projecting from the front of a furnace;

Fig. 9 is a top plan view of part of the worktable of a drop forge showing a die and guiding means associated therewith. This figure indicates the position of a workpiece and its associated tongs in the initial or upsetting position;

Fig. 10 is a view similar to Fig. 9 but showing the workpiece and tongs in a second position;

Fig. 11 is a partial transverse vertical section taken on the line 1111 of Fig. 10;

Fig. 12 is an enlarged view of a detail of the latch mechanism as taken on the line 1212 of Fig. 11;

Fig. 13 is a top plan view (partly diagrammatical) of a second embodiment of my invention showing a series of dies mounted on the table of a drop press and mechanism for mechanically holding a heavy workpiece in various positions with respect to such dies;

Fig. 14 is a side elevational view looking in the direction of the arrows 1414 of Fig. 13; and

Fig. 15 is an end elevational view of the work-holding mechanism shown in Fig. 13 and is taken looking in the direction of the arrows 15--15 of that figure.

In the layout shown in Fig. 1, a workpiece magazine is located adjacent a heating furnace 22 having a table 24 projecting therefrom and overhanging a tongs receiving chute 26. In general, the parts just described form one 'ice side of an L-shaped work station for a man, indicated at 28. The other side of the L-shaped workstation is formed by a drop forge 30 having a work table 52 provided with a die block 34 and guiding means 36. A workpiece receiving chute 38 is located at one side of the die block 34 and delivers forged workpieces to a barrel or other suitable receptacle 40. r

The magazine 20 is shown in more detail in Figs. 3, 4 and 5, and comprises an inclined work-holder 52 supported on legs 44 and 46. The work-holder is adapted to contain a plurality of workpieces 48, one of which is shown in greater detail in Fig. 2. The workpieces 43 are merely illustrative of one of many types of possible workpieces for which my invention is adapted. The particular workpieces 48 are illustrated as having blunt ends '50 and tapered ends 52, the latter being adapted to be engaged by the tongs 54, as hereinafter more fully described. It is important that all the workpieces be of exactly the same length and that they all be assembled in the magazine with their pointed ends 52 extending in the same direction as clearly shown in Fig. 3.

Because of the inclination of the magazine 42 the workpieces are fed by gravity into engagement with an angle iron 54- located at the bottom of the magazine. A plunger or ejector 56 is adapted to reciprocate relative to the magazine 42 to displace the lowermost workpiece in the magazine so that its tapered end 52 projects a predetermined distance from the left-hand side of the magazine as viewed in Figs. 3 and 5. The plunger 56 is normally held in retracted position by a spring 58 and is advanced by depressing a foot pedal 61) which is connected to the ejector 56 by means of link 62 and bellcrank 64-. Movement of the ejector 56 under the force exerted on pedal 60 is limited by engagement of the U-shaped portion of the ejector 56 with the right-hand end of angle-iron 54, and this arrangement insures uniformity in the extent to which the tapered ends of the workpieces project from the left-hand end of the mechanism.

The purpose of causing this projection of the bottommost workpiece from the magazine is to enable this workpiece to be picked up by the tongs 54. As shown in Fig. 2, the gripping jaws 66 of this tongs are specially designed to receive only a predetermined length of the tapered end of the workpiece. Since each workpiece is of the same length, this provides uniform lengths of workpieces projecting from the jaws of the tongs. The angle-iron 54' at the base of the magazine has a projecting end 63 which serves as a guide for the tongs as they are moved into position by the operator to grasp the projecting end of the lowermost workpiece in the magazine.

The operator will normally remove the lowermost workpiece from the magazine by means of tongs held in his left the blunt end of the workpiece engages the upper end of I a guide 70, the operator lowers the tongs and workpiece until the blunt end of the workpiece enters the horizontal slot leading into the furnace chamber. The vertical guides 70 register with a corresponding series of horizontal guides 72 which are primarily effective in aiding removal of the workpiece from the furnace.

When the blunt end of the workpiece enters the slot leading to the furnace the workman pushes the workpiece into the furnace until the ends of the gripping jaws of the tongs are stopped by engagement with the front wall of the furnace. This places the workpiece in the position shown in Fig. 8 with only that part of the piece which is gripped by the jaws of the tongs projecting fromthe furnace slot. This is the proper position for the workpiece during the heating operation, and the operator next opens the jaws of the tongs to release the workpiece and. leave it in this position. The operator. then drops this tongs into the inclined chute 26 whereupon the inclination of the chute causes the tongs to slide by gravity into a depression 74 from which they can be readily removed at the proper time for withdrawing another workpiece from the magazine 20 and inserting it in the heating furnace 22.

The operator ordinarily withdraws a properly; heated workpiece from the furnace 22 by means of another pair, of tongs held in his righthand. This other pair of tongs is shown, at 78 in Fig. 8 and has gripping jaws identical with the gripping jaws 66 shown in Fig. 2. The horizontal guides 72 on the table 24 guide the tongs 78 into engagement with the projecting end of a workpiece 48 (Fig. 8) whereupon the workman closes the jaws and pulls the workpiece out of the furnace. An important feature of this operation lies in the fact that a predetermined part of the length of the workpiece is gripped by the tongs, and the part of the workpiece extending beyond the tongs is also of predetermined length.

The operator now swings the tongs 78 with a hot workpiece therein through a generally horizontal are into a position adjacent the die block 34 and guide or tongs holder 36. He now places the workpiece on edge in an upsetting die 30 and the tongs 78 in the vertically disposed slot 82 in the right-hand side. of the guide 36. This position of the workpiece and tongs is clearly illustrated in Fig. 9. In this connection it will be. noted that the tongs 78 are provided with stops 84 which abut against the forward edge of the guide 36. These stops. 84 are located a predetermined distance from the ends of the gripping jaws 66, and since the abutting surface of the guide 36 has a predetermined positional relationship with respect to the upsetting die 80, and the workpiece projects a predetermined amount from the tongs, the workpiece is accurately positioned in the upsetting die 80. It will be noted that the vertical slot 82 and adjacent shoulder 86 are designed to receive and steady the handles 88 of the tongs while the workpiece is held in this position. Since a single hammer blow is ordinarily sufiicient to upset the workpiece, the operator ordinarily maintains his grasp on the tongs while the workpiece is in the upsetting die 80.

After the workpiece has been upset the operator transr fers the workpiece to the forging die 90-and places the tongs 78 in the recess 92. in the guide 36. In so doing, the operator turns the tongs over so that a flat side of the workpiece engages the forging die 90, and a flat side of the tongs engages the recess 92. This position of the parts is clearly shown in Figs. 10 and 11- and it will be noted from the latter figure that the recess 92 is designed to receive the handles 88 of the tongs. Here also the stops 84 of the tongs engage the forward edge of the guide 36 to locate accurately the longitudinal position of the workpiece in the forging die 90.

The workpiece ordinarily remains in the forging die a sufficient length of time to receive several blows of the hammer, and, in order to conserve the operators time and utilize such time most effectively, I have providedmeans whereby he can release the tongs while the workpiece is in this position. The handles of the tongs 78 are provided with inwardly directed locking members 94 and 96 having inter-engaging ribs or teeth. The resiliency of the tongs normally holds these teeth in engaging position so that the gripping actionof the tongs on the workpiece is maintained after the handles have been released by the operator. I have also provided means for holding thetongs in the groove 92.

This last-named means comprises a bellcrank 98 located in a slot 100 in the guide 36 and adapted to pivot about a screw 102. When the tongs is placed in the recess 92 the arm 104 of bellcrank 98 extends upwardly in a vertical direction and the other arm 106 is substantially horizontal. Placement of the tongs in the recess 92 swings the bellcrank 98 to the position shown in Fig. 11. In this position the arm 104 overlies one handle 88 to lock the tongs in the recess 92. The other arm 106 of hellcrank 98 is held against tong-releasing rotation by a detent 108.

After'the workpiece has been struck the desired number of blows in the forging die 90, the operator grasps and lifts upwardly on the handles of the tongs 78 to raise the tongs and workpiece above the recess 92 and forging die 90. He then swings the workpiece laterally over the chute 38 and causes the tongs to release the workpiece which then drops onto the chute. This release of the workpiece can be effected most easily by engaging the right-handed handle 88 (as viewed in Fig. 10) with an end of chute 38 while exerting a slight downward pressure on the. left-hand handle to disengage the ribs. or teeth on. they locking members 94 and 96. This releasing operation can be easily accomplished with one hand, and this hand is preferably the right hand of the operator.

After causing the tongs 78 to drop the forged workpiece on the chute 38, the operator swings around and uses this tongs to engage and withdraw a heated workpiece from the furnace 22. In so doing, the tongs is quickly and easily brought into engagement with the desired workpiece by the guides 72 and grasps only the predetermined amount of the end of the workpiece which projects from the furnace. This workpiece is then swung horizontally and broughtinto position on the upsetting die 80 while the tongs are located in the slot 82 of the guide 36, as previously-described.

The inclination of the chute 38 is such that the hot workpieces deposited thereon do not immediately slide downwardly to the barrel 40. Instead, these workpieces remain on the slide 38 and gradually work down toward the barrel 40 under the jolting produced by operation of the hammer 32. In this manner I insure that the workpieces will have cooled sulficiently so that they will not be distorted by dropping into the barrel 40.

From the foregoing description it will be seen that in partially projecting the workpieces from the magazine and in each subsequent operation only a predetermined portion of the entire length of the workpiece is available to be gripped by the tongs so that a predetermined re lationship between the tongs and workpiece is maintained throughout all of the operations. In this manner accurate positioning of the workpiece for each operation may be established by accurately positioning the tongs. Furthermore, the operators time and the time of the equipment are most effectively utilized. While the workpiece is in the forging die the operator can grasp the tongs in the receptacle 74, operate the foot pedal 60 to cause the mechanism to project the bottom workpiece, grip this workpiece with the tongs, transfer it to the furnace 22, and drop the tongs in the chute 26. As soon as this is accomplished, the forging of the workpiece in the forging die will have been completed and the operator can remove this workpiece, drop it on the chute 38, withdraw a heated workpiece from the furnace 22, place it in the upsetting die 80, and then transfer it to the forging die 90. It will be understood that the foregoing is only one of many possible procedures utilizing my invention, and that this procedure can be varied to suit differing requirements.

In fact, my invention is not. limited to a procedure in which the workpieces are relatively small and transferred by handfrom oneoperation to another, but is also applicable to a procedure in which a heavy rod, bar, or other workpiece is shifted. by machinery which maybe madeas strong as the circumstances. require. In Figs. 13, 14

and I have illustrated such an application ofmy invention. These figures illustrate a particular form of drop hammer feeding device which will be described as performing a particular series of operations, but here also it is to be understood that my invention may be utilized with many different forms of apparatus designed to carry out either the particular operations described or other operations of a generally similar nature for handling any of a wide variety of forging steps.

In Fig. 13 I have shown a layout comprising a forging table indicated generally by reference character 1211, a cradle 122 for bar stock or other similar workpieces, and 'a machine 124 for supporting and feeding the workpieces to the drop hammer, which is shown diagrammatically. The particular operation contemplated in this layout utilizes a first forming die 126, a second forming die 128, and a cut-off 130, all shown as being supported on the table 120. The cradle 122 is adjacent a guide or stop- 132 which bears a fixed relationship to the machine 124 for accurately positioning workpieces therein.

The cradle 122 is separated from the hammer table 126 so that workpieces can be placed upon the cradle while the hammer is in operation. The Workman, with the aid of an overhead crane or other suitable mechanism, places a piece of bar stock upon the cradle 122 with the end of the stock in contact with the guide or stop 132 which serves to position the stock accurately with respect to the feeding machine 124.

This feeding machine 124 comprises a main frame 134 mounted on supports 136 and 138 attached to the floor and having a predetermined positional relationship with respect to the guide 132 and table 1211 of the drop hammer. It is also to be understood that the forging dies 126 and 128 and cut-off 130 are accurately positioned on the table 120 so that they, too, hear an accurate positional relationship with respect to the feeding machine 124.

The frame 124 has upstanding ends 1411 and 142 terminating in sleeves 144 and 146 respectively in which a work supporting carriage indicated generally by reference character 148 is movably mounted. This carriage has a platform 156 suspended from trunnions 152 and 154 which are rotatably and slidably mounted in the sleeves 144 and 146.

The platform 150 has a pair of supporting sleeves 156 and 158 in which a rod 160 is rotatably and slidably mounted. A collar 162 is attached to the rod 160 and carries a pair of gripping jaws 164 and 166. The latter jaw is pivoted at 168 and is moved between active and inactive position by an air or other iiuid cylinder 170 attached to a collar 172 mounted on the rod 164 In Fig. 13 the jaw 166 is shown in active or gripping position about a bar 174 to be forged.

The jaws 164 and 166 can be moved in a direction toward or away from the fixed stop 132 by means of a second fluid cylinder 1'76 which operates a piston-rod 178 attached at 1811 to the collar 172, whereby the rod 160 is slid axially in its supporting sleeves 156 and 158. This can be used to locate the jaws 164 and 166 properly with respect to the guide 132 and also to move the workpiece lengthwise of the forging dies so that different parts of a long workpiece will be acted upon by successive hammer blows. Where my invention is being utilized to forge a substantial number of identical forgings the adjustment 182 can be set so that when the piston of cylinder 176 is at one extreme position, the jaws 164- and 166 will be at exactly the desired distance from the stop or guide 132. In this connection it should be borne in mind that in Fig. 13 the size of the forging dies is disproportionate to the spacing between the jaws 164 and 166 and stop 132, and that in ordinary usage the latter distance will be greater than the length of the forging dies.

From Fig. 14 it will be apparent that the jaws 164 and 166 project laterally from the axis of the rod 161? to grip the workpiece 174.- In this figure the workpiece is shown in full lines as supported above the rod 166 and in dotted lines as supported at one side of this rod. When the workpiece is on the cradle 122 and is first engaged by the jaws, the jaws are in the position indicated in dotted lines in Fig. 14. The jaws are rotated about the axis of rod 160 by means of an air or other fluid cylinder 184 which drives a rack 186 engaging a pinion 188 splined to rod 160 as indicated at 190.

The entire carriage 148 is moved longitudinally of the frame 134 by two pairs of air or other fiuid cylinders 192 and 1514. The cylinders 192 have pistons and piston-rods 1% attached by links 198 to a pair of cross-members 200 attached to a boss 202 depending from a sleeve 204 which is rotatable relative to the trunnion 154 and confined between collars 2116 and 298 so that movement of the sleeve 204 lengthwise of the frame 134 produces a corresponding movement of the carriage 148.

The other or lower pair of cylinders 194 have pistons and piston-rods 210 connected by links 212 to cross-membars 214 passing through the base 216 of the upstanding end 140* which prevents movement of the cross-members 214 longitudinally of the frame 134.

I have also provided means for tilting the carriage 148 and workpiece 174 about the axis of the trunnions 152 and 154. This is accomplished by 'a collar 218 splined to the trunnion 154 as indicated at 220. The collar 218 has an arm 222 pivotally attached at 224 to the piston and piston-rod 226 of a cylinder 228 whereby operation of the cylinder pivots the carriage 148 about the axis of the trunnions 152 and 154. Since the jaws 164 and 166 and exposed part of the workpiece 1'74 are located at one side of the carriage 143, this tilting movement tends to raise or lower the part of the work-piece upon which work is to be done by the drop hammer.

in operating the feeding machine of Figs. 13, 14 and 15, the workpiece is first accurately positioned in the jaws 164 and 166, as previously described, and with the jaws in the laterally projected position shown in dotted lines in Fig. 14. Cylinder 184 is then operated to rotate the jaws and workpiece to the overhead position shown in full lines in this Fig. 14 which brings the workpiece to a level even with the top of the forging dies 126 and 128.

Cylinder 228 is now operated to tilt the carriage 148 and raise the workpiece above the level of the dies and then the two bars of cylinders 192 and 194 are operated to move the workpiece over the longitudinal center of the first forming die 126. Cylinder 228 is then operated to lower the workpiece into engagement with the forming die and the hammer operated to give the desired number of blows. Where desired, the workpiece can be moved longitudinally of the die by actuating the cylinder 176 so that different parts of a long workpiece will come under the hammer for successive blows. After the workpiece has been exposed to the desired number of hammer blows in this position, cylinder 228 is again operated to raise the workpiece above the dies whereupon cylinders 122 and 194 are actuated to shift the workpiece to a position above the axial center of the second forming die 128. The workpiece is then lowered into contact with this die by operating cylinder 228 and further hammering of the workpiece is carried on. When the forming of the workpiece at the second die 128 has been completed, the workpiece is moved in a similar manner to engage the cut-off whereupon the hammer is again operated to sever the forged end of the bar from the remainder. if the remainder is of such length and shape that it, too, is to be forged, the parts are moved back to the position shown in Fig. 13, the jaws 164 and 166 separated, and the work piece moved toward and into engagement with the stop 132, whereupon it is again gripped by the jaws.

It will be appreciated that where the procedure is standardized the operation of the various cylinders of the feeding machine can be automatically and sequentially controlled by a drum-type cam driven by a synchronous electric motor or other timed mechanism so that the forging operations will not require the attention of the operator who canmove a new" piece. intoposition on the cradle while a previous. workpiece. is. being forged. The automatic timer and air (or other fluid) hose connections to the cylinders are shown diagrammatically in Fig. 13. Throughout all these operations there is a predetermined length of workpiece exposed beyond the jaws in which the workpiece is gripped, and this workpiece is accurately positioned with respect to the dies by accurately positioning the jaws in which theworkpiece. is held so that both this form of my invention and the previously described form employ the same principle.

Attention is directed to the fact that in both embodiments of my invention man power and machinery are utilized most effectively with resulting increased output, reduced cost, and more uniform andimproved products. This is accomplished without materially increasing capital investment.

It is to be understood that my invention is not limited to the particular details shown and described but embody numerous forms and includes all modifications, variations and equivalents'coming within the scopc'of the appended claim.

I claim:

Mechanism for accurately positioninga workpiece comprising pivoted. lever tongs. having an intermediate pivot, workpiece gripping jaws at one side of the pivot and. elongatedhandles at the other side of the pivot, saicl handles having an abutment intermediate their length in combination with a tongs holder comprising a block having: a slot of the Width of said handles, said slot being open at the top and at bothends for receiving a central length of said handles, vertically placed therein and an abutment on said block cooperating with the said handle abutment to accurately locate the tongs as the handles are moved longitudinally through said slot.

References Cited in the file of this patent UNITED STATES PATENTS 29,910 Peck Sept. 4, 1860 31,284 Ballard Jan. 29, 1861 874,561 Best Dec. 24, 1907- 899,285 Best Sept. 22, 1908 i,870,723 Freidman Aug. 9, 1932 2,053,291 Keller Sept. 8, 1936 2,345,572 Brosius Apr. 4, 1944 2,535,215 Klenk Dec. 26, 1950 2,563,677 Frazier Aug. 7, 1951

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