US1836763A - Extrusion press - Google Patents

Description

A. LIEBERGELD EXTRUS ION PRESS Dec. 15, 1931.

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Filed Sept. 29, 1930 f7 Sheets-Sheet 5 A. LIEBERGELD ExTRUsIoN PRESS Filed sept. 29, 1930 7 sheets-sheet 6 Il l I l/ HUIIH HIIIIII lll Il Il Ill Illlll. l

Dec. l5, 1931.

WITNESSES @il-Mix@ Patented Dec. 15, 1931 UNITED VSTATES PATENT OFFICE ALFRED LIEBERGELD, OF LAUFAMI-IOLZ, NEAR NUREMBERG, GERMANY, ASSIGNOR TO FRITZ SINGER, F NUREMBERG, GERMANY EXTRUSION' PRESS Application filed September 29, 1930, Serial No. 485,020, and in Germany July 12, 1928.

My invention pertains to extrusion presses,

and more particularly to the means for imparting movement to the tool or tools employed therein.

In the extrusion of me-tals, for instance to produce tubes, rods and the like, it is important that the operation be conducted at the highest speed which is possible consistently with the obtaining of a satisfactory product. This is in order that cooling-0E of the billet (which would diminish its plasticity) may be minimized and an excessive heating of the tools, by long contact with the hot billet, be avoided. It is further desirable tha't the flow of the metal be initiated at a certain minimum speed; since otherwise there would be danger of the part first extruded becoming cooled sufficiently to freeze fast in the aperture of the extruding die.

After the flowing of the metal has been initiated, there is nothing to prevent the extruding of the main part of the billet from being performed at a speed which is substantially constant and which is as high as is possible consistently with the characteristics of the metal being extruded and other well understood extrusion conditions. The extruding of the last part of the billet should, however, be performed at a lessened speed and under an increased pressure in order to meet conditions arising from the cooling and diminished plasticity of the billet at that stage.

Following out of the speed and pressure formula stated above will give an extrusion speed higher than the ordinary and excellent results; however, it has been difficult of accomplishment with extrusion presses as heretofore constructed. In hydraulic presses the maximum force exerted results unalterably from the water pressure, diameter of plunger and efficiency of the press. In such a press the speed is not predetermined, but is governed by the reciprocal action of the maximum pressure applied by the press, the throttling action at any glven movement of the controllin valve, and the resistance of the billet at t at moment against deformation. In hydraulic presses the ossibilities of influencing the proportions o speed and pressure by throttling or shutting and reopening the controlling valve are only very limited. Likewise, in the case of mechanically driven presses as heretofore ordinarily used, such as the rack and pinion and crank presses, the laws-governing the motions of such presses closely control the speed and pressure effects obtainable. In the case of crank presses, for example, it must be presupposed that the motor power and fly-wheel -masses will be sufficient, and from these the speed unalterably results, whilst the pressure exerted is determined by the resistance of the billet to deformation. It is true that in crank presses the speed of the extruding tool gradually increases from zero to a maximum and then decreases again gradually to Zero. However, in designing such a press with a View to shortening the extrusion time as much possible, there is encountered a maximum speed, towards the center of the stroke, which is sometimes disadvantageous, coupled, atthe end of the stroke, with a retardation which is excessive and beyond anything that is required for the extruding of the billet remainder. Presses of the kinds referred to, therefore, havel not been capable to a sufficient extent of employing at the various extruding stages those speeds and pressures which are best calculated to shorten the 'total time of extrusion and at the same time give a satisfactory product. Moreover, with such presses difficulty has been experienced in slowing up or stopping the extruding operation while in progress, as is often desirable, for example, in extruding Wire in order to enable a workman to insert the end of a new length of wire into a reel.

With the above in View, the principal object of my inventionvis to provide an extrusion press in which, by means simple in character and capable of withstanding the heavy forces to which they are subjected, the speeds and pressure forces at which the extrusion tool or tools operate can be fully accommodated, at each phase of the stroketo the requirements of the extrusion process. It is a. further object of my invention to provide such an extrusion press in which, by simple means, extrusion can be slowed down temporarily or stopped at any stage desired. And other objects of my invention, and advantages obtained thereby, will appear from the following specification.

By way of example, I have shown in the accompanying drawings, and described in the following specification an extrusion press embodying one form of means according to my invention for imparting movement to the extrusion tools. It is to be understood, however, that my invention may be embodied otherwise, and that changes may be made in the particular construction described and shown without eiiceedine` the scope thereof as defined in the appended claims.

In the drawings:

Fig. 1 is a side elevation, partly in section, of an extrusion press constructed in accordance with my invention, shown in its initial position, with a billet in place in the container, ready for extrusion;

Fig. 2v is a front View of the press, likewise partly in section Fig. 3 is a rear view of the press;

Figs. 4-7 are Views similar to Fig. l showing the parts in the positions which they assume, when the plungerA contacts the billet just prior to the piercing operation, when the mandrel has pierced the billet prior to the extruding operation, when the eXtruding operation has just been completed and it remains necessary to sever the residue, and when the residue has been severed, respectively;

Fig. 8 is a plan of the press, partly in section;

Fig. 9 is a fragmentary vertical section through the plunger head and billet container showing a lnodified form of shearingoff means employed when solid rods or the like are to be extruded.

Referring now to Figs. l to 8 the extrusion tools, and means for imparting motion to the same, shown therein for purposes of illustration are adapted for producing a tube by first piercing a billet, then ext-ruding the latter and then cutting ofi the residue remaining in the billet container after the extrusion has been completed. -As shown in such figures, the press includesa frame 1 carrying a fixed table 2 upon which is mounted the billet container 3, in the lower end of which is secured the female die 4. Mounted to slide vertically in suitable ways with which the frame 1 is provided is a punch carrier 5 to the lower part of which is secured thc punch 6, the latterbeing made hollow for the passage therethrough of a mandrel carrier` 7 and mandrel 8. In the lower part of the punch is slidably mounted a centrally disposed shearing member 9 having a shoulder 10 adapted to engage the interior of the punch and thereby retain the shearing member in place in the latter. -An abutment member 11-is secured within the punch for engagement by the shoulder 10 of the shearing member,` the parts being preferably of such dimensions that when the shoulder 10 engages the abutment member l1 the outer end of the shearing member is flush with the end of ythe punch. The shearing member is made tubular to permit the passage therethrough of the mandrel 8 and is adapted to be engaged, at one stage in the cycle of the press, by a shoulder 12 formed at the junction between the mandrel carrier 7 and the mandrel. Vhen thus engaged by the shoulder 7 the shearing member 9 is forced downwardly with respect to the punch for the purpose of shearing-off the residue.

The punch carrier 5 and mandrel carrier 7 are independently actuated, the cycle being as follows: First, the punch carrier and mandrel carrier are moved downward until the punch 6 touches upon the billet 13 in the container (Fig. 4). Next, the mandrel carrier is forced downward with respect to they punch carrier to cause .the mandrel 8 to pierce the billet, during which time the punch carrier may be given a slight upward or retiring movement to accommodate the upward flow of metal resulting from the piercing of the billet (Fig. 5). Next, the punch carrier is forced downward until it has extruded the billet through the female die 4 and around the mandrel 8 to produce the tube 14 (Fig. 6), during Which time the mandrel carrier 7 may remain stationary, if desired, ormay have some movement in either direction. Next, the mandrel carrier is given a further downward movement to cause its shoulder 12 to engage the shoulder 10 of the shearing member 9 and cause such shearing member to move downward beyond the end of the punch Gand enter the hole in the female die 4, thereby shearing off the tube 14 from the residue 15 remaining in the billet container (Fig. 7). Thereafter the parts are returned to their initial position (Fig. 1) ready for the insertion of another billet into the container 3.

For actuating the punch carrier 5 a pair Yof punch-actuating toggles is employed, one

at each side of the press. They are similar, and a description of one pair, therefore, will suffice. Each pair of toggles comprises a link 16 pivoted to the upper part of the press and a link 17 pivoted to the punch carrier 5, the links 16 and 17 being pivoted together in the usual manner. Each toggle link 16 is formed with a rearward extension 18 in which is mounted a cam roller 19 adapted to bear upon a reciprocating cam 20, one of which is provided for each pair of punchactuating toggles.

The cams 20 are connected together through the intermediary of spacers 21 and a central cam 22 (further reference to which will be made below) to constitute a cam assembly which is mounted for vertical slidassegna ing which is disposed on each side of the press punch carrler remamsstationary. (Figs. 1 and 8 The rear edges of the cams constitute racks 24 meshing with pinions 25 the punch carrier 6, andl includes a mandrelcarried by a pinion shaft 26, disposed at the actuatin toggle dlsposed centrall .of the rear of ythe press. Rotary movement, i-rst press. uch togglecomprises a 1in 29 plvin one direction and then in the other, is imoted to the upper part of the press frame 1 l parted to the pinion shaft in any one of a and a link 30 pivoted to the upper end of the number of manners well understood in the j'mandrel carrier 7, the links being pivotally art. Such movement may be uniform or connected with each other in the usual mannen-'uniform in the extruding direction, since ner. The link 29 is formed with a rearward if non-uniform any variations can be accomextension 31 carrying a cam-roller 32 which movement in a pair of ways 23, one of' e, so that Ywhile this surface-is in actonthe The means for o erating the mandrel' cari. 20are dispose vertically and are formed to rier 7 is very simi ar to that fox` operatingv modated by the contours of the cams. The engages the cam 22 above referred to. ,A

pinion shaft, moreover by well understood preure cylinder 33 is pivoted to the cam 22, means, may, if desire be made to rotate and the plunger 34 thereof is connected with more rapidly in the Yreturn direction than in the extension 31, so as to keep the cam roller the extruding direction. 32 in engagement with the cam 22 in the same In order to maintain the rollers 19 firmly manner as the cam rollers 19 are kept in enin engagement with the cams 20, and to cause ga ement with the cams 20. such rollers to rise, in engagement with the he cam 22, which, of course, moves cocams, during the upward movement of the* incidentally with the cams 20, is formed with latter, each of the cams has pivoted thereto a substantiall horizontal surface a which is a pressure cylinder 27, the piston 28 of which in action at t e same time as the surfaces a is connected with the extension 18 of the of the cams 20, having the effect of moving link 16of the associated toggle.` Upward the mandrel carrier 7 downward; Above the pressure is applied to the pistons 28 by water, surface a', the cam 22 is formed with an inair or the like. clined surface b', which is in action at the The cams 20, which are identical, straightsame time as the surfaces b of the cams 20, en the toggles 16, 1,7, thereby to perform the causinr the mandrel carrier 7 to continue to extruding operation during their downward' move downward while the punch carrier 5 is movement. Each cam is formed with a sub- 'moving slightly upward. Above the surface stantially horizontal surface a, which is the b', the cam 22 is formed with a surface c first operatin surface ,to engage the assowhich is in action at the same time as the ciated cam ro ler 19 during the downward surfaces c and d of the cams 20 and which, movement of the cam. When'thc cam surface in the construction shown, causes the mandrel abears upon the cam roller, the latter is forced 8 to move downward while the punch carrier downward, and, owing to the toggle linkage, 5 is moving likewise. Above the surface c', must, of course, moveI forwardly, a straightthe cam 22 is formed with a surface e which ening movement thereby being imparted to is inclined towards the horizontal, thereby thetoggleandthepunchcarrier5being-moved causing the punch carrier 7 to move downdownward. Above the cam surface a each ward, and is in action at the same time as cam is formed with asurf'ace b which inclines the surfaces e of the cams 20, which maintain slightly rearwardly, so that when this surthe punch carrier stationary. face is in action the associated toggle will It will be understood that the actual concollapse somewhat and the punch carrier 5 tours of the various surfaces of the cams rise a little. Above the cam surface b, each will var in accordance with the metal being cam is formed with a surface c which is inextruded and the article produced. For clined towards the horizontal, thereby causexample, the contours of the cams employed ing a straightening movement of the assowhen wire is to be extruded will be different ciated toggle, and i's of such shape that the from those of the cams used in extruding punch carrier 5 `is forced downward at a tubes. speed which is substantially constant and is The operation of the press is as follows: as high as ossibletaking into consideration With the parts in the position shown in the metal being extruded, etc.v Above the Fig. 1, the heated metal billet 13 is inserted surface c each cam is formed with a surface in the container 3 and the press is started, d which inclines more toward the vertical whereby the cams 2O and 22 are caused to than the surface c, with the eifect that the move downward in the ways 23 by the rack speed of downward movement of the punch and pinion movement 24, 25. The surfaces I carrier 5 is lessened, and the pressure exa and a of the cams 20 and 22 being suberted by the punch carrier is correspondingly stantially horizontal and coming into action increased. This surface d is timed to come simultaneously, the rollers 119 and 32 are into action at the extrusion of the last part of simultaneously moved downward and tothe billet. Above the surface d each cam is wards the press frame. The result is that 65 formed with a substantially vertical surface the punch carrier 5 and mandrel carrier 7 130 move downward together and-'the'toggles- 16,

' 17 and' 29, 30 arepartly straightened, the

punch carrier 5 and mandrel carrier 7 mov-A ing downward together until the punch 6 touches upon'the billet 13 (Fig. 4). Thereupon, during the further downward movemen't of the cams, the surface b ofthe cam 22 comesinto action, causing the mandrel 16, 17 to collapse somewhat and the punch carrier to be raised a little under the pressure of the piston 28. t tinues its downward movement, piercing the billet, while the punchrecedes a little, to

provide for theu ward flow of the metal resulting -from suc piercing (Fig. 5). During the further downward movement of the cams, the surfaces 'c an'd'd of the cams 20 successively come into action, causing the punch carrier first to be forced downward at a relatively high speed and then, towards the end of its stroke, at a lower speed. At the same time, in the construction shown, the surface c of the cam 22 is in action and is causing the mandrel 8 to descend with the punch, thereby bringing the parts to the position shown in Fig. 6, where the billet is entirely extruded, leaving oniy the residue 15 in the container. As the cams move downward further, the surface e of the cam 22 comes intoI action, causing the mandrel carrier' 7 to continue its downward movement, although, due to the vertical surfaces e of the cams 20, the punch carrier 5 remains stationary. Such further downward movement of the mandrel carrier brings its shoulder l2 into engagement with the shoulder 10 of the shearing member 9, whereby such shearing member is forced downward with respect to the punch 6 so as to enter the aperture of the female die 4, thereby shearing-off the tube 14 from the residue and ejecting the tube from the die. This completes the downward movement of the cams. Upon their upward movement, of course, the parts return to the original position shown in Fig. 1.

It will be seen that, bythe above cam construction, the speeds and pressures at which the extruding tool or tools operate at any stage in the cycle, can be determined in complete accordance with what may be found to be desired. Further, by properly shaping the cams, the extrusion step may be slowed down or stopped at any point in order to meet such practical conditions as may present themselves, as for instance where the end of a new length of wire is to be inserted in a reel, etc.

In the extrusion of rods and other solid articles, the piercing step will, of course, be omitted. In that event a plunger 7 (Fig.l 9) may be employed in pla'ce of the mandrel Thus the mandrel 8 con-y Lasarte carrier'l' and 'its' end made' to en age against a solid shearing member 9 user? in place of the hollowv shearing member 9. The cam contours will, of, course, be vmodified accordingly. A Y

I claim: I

1. Aiiextrusion press comprising a pair of members mounted for coaxial reciprocating movement, (ya, toggle device for each of said members to effect movement thereof, and a cam foreach of said toggle devices to actuate the same.

2. An extrusion presscomprising a reciprocating member, a toggle devicev for actuating the same, a reciprocating cam Yfor operating said toggle device, and a pressure cylinder associated with said toggle device to maintain the same in operative relation with said cam.

3. An extrusion press comprising a pair of members mounted for coaxial reciprocatin movement, a toggle device for each of sai members to effect movement thereof, a reciprocating cam for each .of said toggle devices to actuate the same, and a pressure device associated with each of said toggle devices to maintain the same in operative relation with their respective cams.

4. An extrusion press comprising a reciprocating extruding member, a toggle device for actuating the same, and a canr for operating said toggle device, said cam being shaped to impart to said member an initial extruding movement, then a further extruding movement at a higher and substantially constant speed, and then a .final extruding movement at lower speed.

5. 'An extrusion press comprising an extrudmg member mounted for reciprocating movement, a tool mounted coaxially with said extruding member, a toggle device for actuating said tool, a pair of toggle devices, oneon each side of said first-named tog le device, for actuating said member, a cam for actuating said first-namedI toggle device, and cams for actuating said pair of toggle devices.

6. An extrusion press comprising an extruding member mounted for reciprocatin movement,r a tool mounted coaxially witlgi said extruding member, a toggle device for actuating said tool, a pair of toggle devices, one'on each side of said first-named toggle device, for actuating said member, a reciprocating cam for actuating said first-named toggle device, reciprocatingcams for actuating said pair of toggle devices, and means for reciprocating said cam and cams together. 7. An extrusion press, comprising a reciprocating member, a toggle device for operating the same, a reciprocating cam adapted to be moved in a direction parallel to the direction of reciprocation of said member, means for transmitting the movement of said cam to said toggle device, a second member guided within said first-named member and adapted to reciprocate in the same axis as said first-named member, a second toggle device for operating said second-named reciprocating member, a second cam adapted to be moved in a direction parallel to the direction of reciprocation of said second-named member, and means for transmitting` the movement of said second-named cam to said second-named reciprocating member.

8. An extrusion press for extruding tubes comprising a hollow extruding punch, a shearing off member movably mounted in said punch, a mandrel mounted for reciprocating movement in said punch, said mandrel having a shoulder associated therewith for engagement with said shearing off member, a toggle device for actuating said punch to perform the extruding operation, a second toggle device for actuating said mandrel to pierce the billet and subsequently to cause said shoulder to engage said shearing off member to actuate the latter, and reciprocating cams for operating said toggle devices.

9. An extrusion press as set forth in claim 8 comprising a reciprocating cam for actuating the toggle device for the punch, said cam being shaped to move the punch at high speed up to the time of reaching the billet, then to permit a backward movement of the punch during piercing of the billet, then to move the punch downward to initiate flow of the metal in extruding the billet,lthen to move the punch downward at a higher speed to extrude the main portion of the billet, and then to move the punch downward at a lower speed to extrude the last portion of the billet.

10. An extrusion press as set forth in claim 8 comprising a reciprocating cam for actuating the toggle device for the punch, said cam being shaped to move the punch at high speed up to the time of reaching the billet, then to permit a backward movement of the punch during piercing of the billet, then to move the punch downward to initiate flow of the.

metal in extruding the billet. then to move the punch downward at a higher speed to extrude the main portion of the billet, and then to move the punch downward at a lower speed to extrude the last'portion of the billet, and a reciprocating cam for the toggle device for the mandrel, said last-named cam being shaped to move the mandrel downward with the punch until the latter reaches the billet, to move the mandrel downward. to pierce the billet, during the backward shearing off member, a tog le device for actuating said punch to per orm the extruding operation, a second toggle devlce for actuating said element to cause it to engage and operate said shearing off member, and reciprocating cams for operating said toggle devices. i

In testimony whereof, I hereunto sign my name.

ALFRED LIEBERGELD.

movement of the punch and to move the mandrel downward after the extruding operation' to actuate the shearing oif member.

11. An extrusion press comprising a hollow extruding punch, a shearing of member movablymounted in said punch, an element' mounted for reciprocating movement 1n sald p unch'and adapted for engagement with said

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