US2936018A - Apparatus for straightening metallic extrusions - Google Patents

Description

May 10, 1960 E. J. DE RIDDER ETAL APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 9 Sheets-Sheet 1 Fig. l

IN VEN TOR. m} .mbxenauu ATTORNEY Mair 10, 1960 E. J. DE RIDDER ETAL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS 9 Sheets-Sheet 2 Original Filed July 12, 1955 N A A v 3 W 3:5

i 1 A a ATTORNEY y 1960 E. J. DE RIDDER ETAL 2,936,018

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APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 9 Sheets-Sheet 4 Fig.5

INV NTO his 1 M,

ATTORNEY y 1960 E. J. DE RIDDER ETAL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 9 Sheets-Sheet 5 INVEINPTOR. .fllide".- f w ATTORNEY y 6 E. J. DE RIDDER ETAL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 9 Sheets-Sheet 6 ATTORNEY y 1960 E. 'J. DE RIDDER ETAL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 Fig. 14- I a 9 Sheets-Sheet '7 ATTORNEY May 10, 1960 E. J. DE RIDDER ET AL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 9 Sheets-Sheet 8 F:.g.l5

INVENTORS M 44 im qgg zw ATTORNEY May 10, 1960 E. J. DE RIDDER ETAL 2,936,018

APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Original Filed July 12, 1955 I 9 Sheets-Sheet 9 1 H l n n n :1

IN VEN TORS W 92 My 27 L6 ATTORNEY APPARATUS FOR STRAIGHTENING METALLIC EXTRUSIONS Ernst J. De Ridder and Kurt F. Glaser, Richmond, Va.,. assignors to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Continuation of application Serial No.

1955. This application August 3, 831,431

521,557, July 12, 1959, Serial No.

F 18 Claims. (Cl. 153-32) The present invention relates to a method and apparatus for producing untapered and/r tapered extrusions of many shape configurations straightened to very closev tolerances in one or several draw operations.

This application is a continuation of application Serial No. 211,557, filed July 12, 1955 and now abandoned.

To straighten an untapered extrusion by drawing it through a draw die has been common practice for many years. In a steel disc an opening is out which corresponds very correctly to the cross sectionof the extrusion and the shape is pulled through this die for straightening purposes. a

. Thismethod cannot be used if the extrusion is tapered having a thick wall thickness at one end and a thin one at the opposite end. It also cannot be used on wide extrusions having thin wall thicknesses :and complex shape configurations since such rigid draw dies to not provide flexibility for variations. in wall thicknesses caused by toler ances which are inevitable in the extrusion process. -A characteristic of our method and apparatus is that each extrusion is longitudinally, and if necessary, repeatedly drawn through a specially formed hydraulic straightening die, in which movable die parts are mounted for varying the die opening according to wall thickness variations of the extrusion. 7

- The apparatus and general method will be described with reference to the accompanying drawings, in which:

Figure 1 is a sectional view of a hydraulic die embodying the invention, for straightening a simple rectangular extrusion;

Figure 2 is a sectional view of a hydraulic die of the invention for straightening an extrusion in the form of a T section;

Figure 3 is a sectional view of a hydraulic die of the invention for straightening a wide integrally stiffened extrusion;

Figure 4 is a sectional view illustrating a modification of the hydraulic die for the extrusion shown in Figure 3; Figure 5 is a cross section taken on line 5- -5 of Figure 4; I

Figure dis a schematic fragmentary perspective view showing a split tubular extrusion set up -in a break-press, diagrammatically shown, for the first step of preliminary flattening of an integrally stiffened'extrusion;-

Figures 7 to 11 inclusive are diagrammatic views showing the five pressure strokes and four position changes employed in the preliminary flattening of theextrusion of. Figure 6;

Figure 12 is a plan view of our hydraulic die for straightening an integrally stiffened extrusion, and embodying the movable core members, the upper pressure shoe not being shown; Figure 13 is a front elevation, partly broken away, showing he structure of Figure 12, a stiffened sheet undergoing straightening being shown, partly in dot and dash line at the top of the figure;

Figure 14 is a vertical section taken onthe line 14-14 of Figure 12;

Figure 15 is a plan view of one of the steel cores;

Figure 17 is a view in elevation showing the side of a steel core in the center or inner areas of our hydraulic die;

Figure 18 is a view similar to Figure 17 showing the,

the form, of steel core adapted for end positions of our hydraulic die;

Figure 19 is a plan view, partly broken away, showing an end area of our hydraulic die adapted for supporting;v

elements of T-shape; I

Figure 20. is a view in front elevation of the structure shown in Figure 19, part of a stiffened sheet with T-,

stifiening members being shown in position, and partly by dot and dash line;

Figure 21 is an end elevation, partly in dot and dash lines showing the structure of Figures 19 and 20, with overhead pressure shoe member in position;

Figure 22 is a longitudinal vertical section taken on the line 22.-22, Figure 19, with a stiliened sheet, shown in dotted lines in position;

- Figure 23 is an enlarged view in elevation partly in Section, showing members 11, 17, 18 and 19, the latter be-' ing in section;

Figure 24 is a schematic sectional view showing the mounting of the frame which holds all of the'die elements, including the uppermost pressure head, for movement in inclined positions relatively to the stiffened sheet with the effect that the draw bench in any stretch of the planar element of the sheet will correspondingly stretch the headedstiffening elements; 7 V

Figure 25 is a schematic view of adou'ble draw bench; and

Figure 26 is a schematic view of a double acting single draw bench.

Referring to the drawings, Figures 1-5, illustrate suitable apparatus enibodying the present invention, and de signed for straightening several types of metallic extru- SIOHS.

In Figure 1, a hydraulic die'for straightening a simple rectangular extrusion is shown. This die comprises a main frame 33 which also serves as the upper die part. Bolted within frame 33 and at the bottom thereof is a cylinder block 9. Block 9bears a cylinder in which is disposed a movable piston 11 having at its upper end the lower die part 11a. A port 27 is provided for the admission of hydraulic fluid to the cylinder. The rectangular metallic extrusion to be straightened by the die of Figure 1 is shown at 5.

Referring to Figure 2, there is shown a hydraulic die for straightening an extrusion in the form of a T section, In this die, cylinder block 9 bolted to the main frame 33 contains two cylinders, each bearing a piston 11. Each of. pistons 11 provides at its upper end an angular lower die part 11b adapted to abut the two inner intersect ng surfaces on one side of the T section 5. A suitable by draulic system admits hydraulic fluid to the cylinders,

The hydraulic die of Figure 3 is designed for straightening a wide integrally stiffened extrusion. Here again, a frame 33 forming an upper die part has bolted therein a cylinder block 9. Cylinders are provided in block 9 for pistons 11 hearing the lower die pieces or cores 16, \and also for pistons 12 which provide pressure heads 22 for supporting the leg portions of the extrusion. The two pairs of pistons are operated by hydraulic system 27.

Referring to Figures 4 and'5, a modification of the hydraulic die of Figure 3 is shown, particularly adapted for straightening extrusion 5 along its baseline 5x. Here, the movable die parts 16 carried by pistons 11 press against the upper surface of therextrusion, the latter being supported on two base portions 33x, which are vertically Patented May 10,, 19.60

Figure 16 is an end view of the core shown in Figure:

3 immovable. These latter base portions, however, may slide laterally of the direction of draw through the die, due to the dovetail construction at 32. Cylinder blocks 9 and 9x, bolted together by bolts 28, are provided respectively for the piston members 11 and '12. Two independent hydraulic systems 27 and 27x operate the pistons.

Referring to Figures 6ll, a method of preliminarily flattening the integrally stiffened extrusion of the type shown in Figures 35 is illustrated. This method employs a break-press (Figure 6), which is as long as the length of the extrusion. This press comprises two movable sections 1 and 2, which are adapted to engage the legs of the extrusion as shown in Figures 7-11. Fixed to the upper member 4 of the press is a strip of rubber indicated at 4a. The extrusion 4 is placed in the press as shown in Figure 6, and is straightened in a succession of steps as indicated'in Figures 7-11.

Referring to Figures 12, 13 and 14, there is provided what may be termed a cylinder block formed by a base member 6, a vertical wall member 7, an opposed and spaced vertical wall member 8, and an internal block 9, bolted together by the screws or bolts The internal walls of members 7, 8 and 9 are shaped so as to provide a set of cylinders to receive pistons 11 for acting upon the steel cores later to be described, and intermediate and smaller cylinders which receive pistons 12 which act upon pressure heads '13 for the stiffening legs of the extrusion. In Figure 13 one of the extrusions is shown in dot and dash lines at 14, and the ends of the stiffening legs 15 are of the bulb type.

Each steel core is preferably formed with a wall which tapers at both sides of a flattened apex, and in Figures 15 and 16 the steel core is indicated at 16, and its contact apex at 16x. Depending from the core head is a rounded shank 17 having a convex base at 18.

As shown in Figure 13, the convex base of each steel tops correspondingly formed as indicated at 25, left-hand end of Figure 13, or 26, right-hand end of Figure 22. In such cases, the steel cores may be somewhat modified as shown in Figure 18 at 16xx.

For admitting hydraulic pressures to each of the pistons 11 for the appropriate steel cores, the die wall assembly is formed with suitable ports leading to the base of each cylinder which encloses a piston 11, one of said ports being shown at 27, Figure 13, and similar ports are provided for the cylinders in which the smaller pistons 12 are actuated, as indicated for example at 29, Figures 13 and 14, and in Figure 22.

Shown in Figure 25 is a schematic view of a double draw bench comprising draw benches 34 and 34x. 35 is the hydraulic die which can be tilted, while 36 and 36x are the carriers for extrusion 5. These carriers are connected by hooks 37 and 37x, respectively, to pulling chains 38 and 38x.

Referring to Figure 26, a schematic view of a doubleacting single draw bench 39 is shown. Die 35 is mounted on carrier 40. Extrusion 5 is held by clamping devices 41 and 41x, only one clamp being in action at a time. Here again, hooks 37 and 37x are provided, connecting the die carrier to the pulling chain 42, and only one hook is in action at a time.

In the operation of our draw die, a stilfened sheet 5 is placed in position relatively to the steel cores 16 and pressure head 33, as indicated in the drawings. The front end of the sheet is gripped by clamps (not shown) of draw-bench carriage 36, as illustrated in Figure 25, and the stiffened sheet is repeatedly drawn through the die in reversing cycles. By using a draw-bench carriage at opposite ends of the stiffened sheet with the usual draw-bench operating members including chains, the

core rests in the concave top seat of an annular steel sion is straightened, the legs and formed ends of the block 19 supported upon the upper end of a piston 11 for limited transverse movement. As will be seen from Figures 14 and 23, block 19 is formed with a recess which receivesthe head 111: of the piston 11. The recess of the block 19 is formed with straight sides to conform A with the sides of the head but is wider at two of its opposed sides to permit limited shift of block 19 transversely of the walls 7 and 8 of the assembly.

Between the steel cores 16 are positioned the pressure heads 13 for the legs of the stiffened extrusion 14. Each pressure head 13 is supported upon the top of its appropriate piston 12 and may be detachably connected to the latter. In the form shown in Figure 13 an apertured lug 12x projects into a slot formed in the head 13, a pin 21 holding the elements together. In the form shown in Figure 22 the pressure head is formed with two base recesses which receives two pistons. (See also 30 in Figure 19.) Either expedient may be employed, as desired.

It will be seen from Figure 13 that the pressure heads .13 have top recesses conforming with the bulb tips of the stiffened sheet legs 15, whereas the pressure heads 22 of Figure 22 lack such recesses at their tops to conform with the T-legs of the stiffened sheet 14x.

In some cases it may be desirable to employ an elongated pressure head for the stifiened sheet leg intermediate each pair of steel cores, and in Figures 19 and 20, each'elongated pressure head 30 is acted upon by two pistons in cylinders indicated by dotted lines at 31, Figures 19 and 21.

Inasmuchas the stiffened sheets may, at their sides in some cases, lack legs of the type shown in Figure 13 or the type shown in Figure 22, but may have merely the short bar-like leg 23 of Figure 13, or the rounded reinforcing member 24 of Figures 20 and 22, the pressure stiffened sheet may be drawn back and forth, as will be understood without further explanation.

Since in such operation, with the stiffened sheet 5 being pulled in a straight line, only the top portion of the extrustiffened extrusion will not be stretched, and this will cause a longitudinal bow in the sheet. To avoid this bow, the die 35 may be set at an adjustable angle to the direction of draw, as indicated in Figure 24, schematically. In that figure, the angle is acute, and beyond that actually required, and for the purposes of illustration only. By means of such angles, the legs of the stiffened sheet are stretched.

By means of hydraulic pressure, the steel cores are pressed against the underface of the web or top portion of the extrusion, and therefore against the top die piece 33, Figures ,21 and 24., The pressure heads which act upon the bottoms of the legs may be given a less hydraulic pressure than that exerted by the steel cores, and their action is to prevent lines .of depression in the top of the extrusion which might occur between the steel cores in the absence of the said pressure head.

As shown more particularly in Figure 23, the steel cores have a somewhat lesser width than the spacing between the legs of the stifiened sheet, and the base of each steel core is enabled to shift angularly because of its concave base and the convex seat provided therefor in the steel block 19, Figure 23. Also the steel block may shift bodily with the steel core and relatively to the head 11x of the piston 11. Thus irregularities at the under face of the stiffened sheet and in the sides of the legs thereof will not cause shearing action by the steel cores, but rather they will have an ironing and somewhat kneading action at areas of irregularity, the top portion of the extrusion being straightened within close tolerances. v The hydraulic die of our invention has special application for stretching tapered extrusions. There is usually a need to stretch extrusions after heat treatment to eliminate non-uniform residual stresses. Tapered extrusions cannot be stretched in the dies of the prior art because heads at the ends of the die assembly may have their the cross sectional area of the thin end of the extrusion isto6' small to permit sufficient stress for stretching" the portions of thicker cross-sectional area. When using the hydraulic die of our invention, however,'this problem is overcome. While pulling the extrusion through the die, the local stretching eflect shifts progressively along the length of the extrusion. The thick end of the tapered extrusion is pulled first through the die, the hydraulic pressure is decreased according to the decreasing crosssectional area of the extrusion, and the danger of overstressing at the thin end of the extrusion is eliminated.

We claim:

1. Apparatus for straightening an elongated sheet-like metal extrusion comprising: a draw die frame adapted for passage of the extrusion therethrough; means defining die surfaces carried by said frame for straightening and smoothing engagement with one of the faces of the extrusion on its said passage, said surfaces being fixed against movement normally of the plane of the extrusion during its said passage; a row of die members carried by said frame for movement substantially normal to the plane of the extrusion in its said passage through said frame, said row being disposed transverse to the direction of said passage and each of said members having a die surface opposed to said fixed die surfaces and engageable with the other face of the extrusion for straightening and smoothing the latter on said passage; fluid pressure means associated with each of said die members for individually yieldably urging the latter against the extrusion during said passage; and means for supplying each of said fluid pressure means with fluid under pressure.

2 The structure defined in claim 1 in which the opposed die surfaces converge toward each other in the direction of said passage.

3 The structure defined in claim 1 in which the opposed die surfaces diverge outwardly from each other in opposite directions from a midpoint of minimum separation therebetween, whereby the extrusion may be passed in either of said directions through the fame.

4. The structuredefined in claim 1 including means rigidly carried by the frame and slidably engaging the die members for guiding the latter in their said normal move- :ments while restraining them against any rocking movements about axes transverse to the direction of the said passage, but permitting rocking movements about axes extending'in the direction of said passage, and including curved interengaging force-transmitting surfaces between each die member and its corresponding fluid pressure means for permitting said last-mentioned rocking movement.

5. Apparatus for straightening an elongated sheet-like metal extrusion'having on one of its faces at least one 1 substantially-straight integral stiffening rib, the combination comprising: a draw die frame adapted for passage of the extrusion therethrough; means defining die surfaces carried by said frame for straightening and smoothing engagement with one of the faces of the extrusion on its said passage, said surfaces being fixed against movement normally of the plane of the extrusion during its said passage; a row of die members carried by said frame for movement substantially normal to the plane of the extrusion in its said passage through said frame, said row being disposed transverse to the direction of said passage and each of said members having a die surface opposed to said fixed die surfaces and engageable with the other face of the extrusion for straightening and smoothing the latter in its said passage through said. frame; fluid pressure means associated with each of said die members for individually yieldably urging the latter against the extrusion during said passage; and means for supplying each of said fluid pressure means with fluid under the same pressure.

6. The structure defined in claim 5 including another die member carried by the frame in spaced relation to the movable die members in the row and for movement parallel to the latter, said die member having a die surface engageable with the edgeof' the rib-on the extrusion on passage ofthe latter through said frame; another fluid pressure means associated with said die member for yieldably urging the latter against the rib edge during said passage; and means for supplying said last-mentioned fluid pressure means with fluid under pressure.

7. The structure defined in claim 5 including another die member carried by the frame in spaced relation to the movable die members in the row and for movement parallel to the latter, said die member having a die surface engageable with the edge of the rib on the extrusion on passage of the latter through said frame; another fluid pressure means associated with said die member for yieldably urging the latter against the rib edge during said passage; and means for supplying said last-mentioned fluid pressure means with fluid under 'a lesser pressure than that supplied by the supplying means recited in claim 5. I

8. The structure defined in claim 5 in which the die surfaces on the die members in the row are adapted to" engage the ribbed face of the extrusion and two of said die members which are adjacent are spaced apart in the row for passage of the extrusion rib therebetween.

9. The structure defined in claim 5 in which the die surfaces on the die members in the row are adapted to engage the ribbed face of the extrusion and two of said die members which are adjacent are spaced apart in the row for passage of the extrusion rib therebetween, and including another die member carried by the frame between said two die members and for movement parallel to the latter, said die member having a die surface engageable with the edge of the rib on the'extrusion for straightening and smoothing the latter on passage thereof through the frame; another fluid pressure means associated with said die member for yieldably urging the latter against the rib edge during said passage; and means for supplying said last-mentioned fluid pressure means with fluid under pressure.

1 0'. The structure defined in claim 5 in which the die surfaces on the die members in the row are adapted to engage the ribbed face of the extrusion and two of said die members which are adjacent are spaced apart in the row for passage of the extrusion rib therebetween, and including another die member carried by the frame between said two die members and for movement parallel to the latter, said die member having a die surface engageable with the edge of the rib on the extrusion for straightening and smoothing the latter on passage thereof through the frame; another fluid pressure means associated with said die member for yieldably urging the latter against the rib edge during said passage; and means for supplying said last-mentioned fluid pressure means with fluid under a lesser pressure than that supplied by the supplying means recited in claim 5.

'11. The structure defined in claim 5 including a draw bench, and means mounting the die frame on said bench for pivotal adjustment about an axis substantially parallel to the row and disposed between the opposed die surfaces.

12. Apparatus for straightening an elongated sheetlike metal extrusion having on one of its faces a plurality of substantially straight and substantially parallel stiffening ribs, the combination comprising: a draw die frame adapted for passage of the extrusion therethrough; means defining die surfaces rigidly carried by said frame for straightening and smoothing engagement with the other face of the extrusion on its said passage through said frame; a row of die members carried by said frame for movement substantially normal to the plane of the extrusion in its said passage through said frame, said row being disposed transversely of the direction of said passage and each of said members having a die surface .opposed to said fixed die surfaces and engageable with the one face. of the extrusion for straightening and smoothing the latter in its said passage through said frarnaadjacent die members being spaced apart in said row for passage of the ribs therebetween; additional die members carried by said frame for movement substantially parallel to and disposed between said die members in said row, each of said additional die members having a die surface engageable with the edge of one of the ribs of the extrusion for straightening and smoothing the latter in its said passage through said frame; fluid pressure means associated with each of said die members for individually yieldably urging the latter against the extrusion during said passage; and means for supplying each of said fluid pressure means with fluid under pressure.

13. The structure defined in claim 12 in which the supplying means supplies each of the fluid pressure means associated with a member in the row with fluid under the same pressure, and supplies each of the fluid pressure means associated with the additional members with fluid under the same; but a lesser, pressure than said firstmentioned pressure.

14. The structure defined in claim 12 including means rigidly carried by the frame and slidably engaging the die members in therow for guiding the latter in their said normal movements while restraining them against any rocking movements about axes transverse to the direction of said passage but permitting rocking movements about axes extending inthe direction of said passage, and including curved interengaging force-transmitting surfaces between each die member in the row and its corresponding fluid pressure means for permitting said last-mentioned rocking movement.

15. The structure defined in claim 12 including means rigidly carried by the frame and slidably engaging the die members for guiding the latter in their said normal movements while restraining them against any movement parallel to the direction of the passage of the extrusion through the frame but-permitting movement of each of the die members in the row transversely of said direction, and interengaged force-transmitting surfaces between each die member in the row and its corresponding fluid pressure means for permitting said last-mentioned transverse movement.

16. Apparatus for straightening an elongated sheetlike metal extrusion having on one of its faces a plurality of substantially straight and substantially parallel stiffening ribs, the combination comprising: a draw die frame adapted for passage of the extrusion therethrough; means defining die surfaces carried by said frame for straightening and smoothing engagement with the one face of the extrusion, between the ribs thereon, on passage of the extrusion through said frame, said surfaces being fixed against movement normally of the plane of the extrusion during its said passage; a row of die members carried by said frame for movement substantially normal to the plane of the extrusion in its said passage through said frame, said row being disposed transverse to the direction of said passage and each of said members having a die surface opposed to said fixed die surfaces and engageable with the other face of the extrusion for straightening and smoothing the latter in its said passage through said frame; additional die members carried by said frame for movement substantially parallel to the direction of movement of said die members in said row, each of said additional die members having a die surface engageable with an edge of one of the ribs on the extrusion for straightening and smoothing the latter in its said passage through said frame; fluid pressure means associated with each of said die members for individually yieldably urging the latter against the extrusion during said passage; and means for supplying each of said fiui pressure means with fluid under pressure. f

17. The structure defined in claim 16 in which each of the fixed die surfaces is formed on a separate die mem ber, and including means mounting the latter on the frame for movement transverse to the direction of movement of the extrusion in its passage through said frame.

18. Apparatus for straightening an elongated sheetlike metal extrusion having on one of its faces at least one substantially straight integral stiffening rib, the combination comprising: a draw bench; a draw die frame adapted for-passage of the extrusion therethrough and carried by said bench; means defining opposed die surfaces carried by said frame for straightening and smoothing engagement with the opposite faces of the extrusion on its said passage through said frame, means for urging said die surfaces engageable with one of the faces of the extrusion, against the latter; and means mounting said frame on said bench for pivotal adjustment about an axis disposed transverse to the direction of said passage, substantially parallel to the plane of the extrusion in its said passage, and between said opposed die surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 1,103,382 Seifert July 14, 1914 1,437,953 Baily Dec. 5, 1922 2,178,674 Simons Nov. 7, 1939 2,301,960 Lermont Nov. 17, 1942 r 2,379,658 Saunders July 3, 1945 2,680,976 Hessenberg July 15, 1954 2,692,421 Cozzo Oct. 26, 1954 2,767,767 Peterson Oct. 23, 1956 2,799,317 Toulmin July 16, 1957 2,872,964 Hollis Feb. 10, 1959 FOREIGN PATENTS 119,427 Great Britain Oct. 3, 1918

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