US2974710A - Metal working device - Google Patents

Description

K. F. BRAEUNINGER 2,974,710 METAL WORKING DEVICE March 14, 1961 Filed Feb. 10, 1958 4 Sheets-Sheet 1 IN V EN TOR. Aar/ F firoeun/nyer ATTORNEYS March 14, 1961 METAL WORKING DEVICE Filed Feb. 10, 1958 4 Sheets-Sheet 2 NPJJ IN V EN TOR. Kar/ F. 51-0 eun Inger ATTORNEY;

K. F. BRAEUNINGER 2,974,710

March 14, 1961 BRAEUMNGER 2,974,710

METAL WORKING DEVICE 4 Sheets-Sheet 3 Filed Feb. 10, 1958 WNW 1 aw 8N WN mw m3 Nam HTTORNEYS March 14, 1961 K. F. BRAEUNINGER METAL WORKING DEVICE Filed Feb. 10, 1958 4 Sheets$heet 4 will) w 4 553 INVENTOR.

BY /(or//-T Braeun/nyef ,QTTORNEYS Un t d States P te '5 METAL WORKING nnvrcn Karl F. Braeuninger, Ferguson, Mo., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware This invention relates to means for straightening and correcting the contour'of sections of'metal, and particularly to a machine for straightening and correcting I the contours of extruded sections.

Extruded parts as they emerge from an extrusion press are reasonably straight if the die is properly designed. They are, moreover, hot. The temperature in some cases, due to very high extrusion speed, is even higher than the temperature of the billet when the billet enters the extrusion press. The parts, therefore, are in a relatively soft condition. The slightest force due to unsymmetrical flow of the metal through the die orifice, or even the weight of the part of portions of the shape, will cause distortionof the contour or longitudinal blending.

It is well known in extrusion practice that there are always certain irregularities in flow conditions, temperature, and friction during the extrusion process. These differences in flow superimpose additional forces in a transverse direction, resulting in bending or distortion of the extrusions.

i In order to minimize these adverse effects, it is common practice to use pulling devices whidh keep the emerging section under adequate tension. However, in order to prevent warping it would be necessary, in many cases, to apply tensions far exceeding the hot yield strength of the material. Even higher tensions would have to be applied in order to maintain correctness of contour in cases where the irregular metal flow is tending to cause distortion of certain portions of the cross-section of the extruded shape. When the contour of the extruded shape tends to warp, other devices and methods are applied which, in general, comprise a great variety of roll guides, sliding guides, graphite blocks, etc. These devices, in fact, effect straightening or correcting of the extruded shapes immediately after they emerge from the die orifice. However, they do not always produce the desired degree of correctness or trueness of dimension and additional corrective operations remain to be done separately on special machines outside of the extrusion press or rolling mill.

The customary production method of straightening and correcting shapes is to use multiple rolls which are all in one plane and staggered with respect to each other. The rolls must have configurations which retain the work piece while it is straightened.

As the piece passes between the straightening rolls, it is bent back and forth to a lessening degree until it emerges from the last rolls, where only a very small bending stress is applied. Under normal conditions, it has retained its original contour and is straight.

In many cases, it is necessary that a complete lot of material, after it has been straightened in one plane, still remains to be straightened in another plane. In order to straighten in a'second plane, machines of the above mentioned type have to be reset, the rolls changed,

and the entire lot of material is again run through at right angles to the first pass. Such requirements led to the development of two plane straightening machines.

2,974,719 Patented Mar. 14, 1961 Essentially, two plane rolling machines are composed of a pair of single-plane shape-straightening machines, one at right angles to the other. The second portion of rolls (or horizontal section) is arranged so that it can be adjusted to accommodate the varying center lines of the work piece as they are established from the vertical section. Here, many variations in driving the rolls are applied. On single types, only the vertical portion of the machine is driven. This also acts as a pinch roll for driving the sections through the remaining horizontal roll stands. However, the majority of machines are driven in both sections. A single drive shaft in connection with bevel gears drives the horizontal and vertical section so that synchronized rotation is assured.

Regarding the centerlines, such machines are either of the fixed center type or of the variable center type, the latter being more versatile than the fixed center type. In the latter type the bending span can be varied. If the planes of the material to be straightened are not at right angles to each other, machines have been developed in which the angle between the planes can be varied. Such machines are called multi-plane straighteners. Many of the above-described features are applied individually or in combinations to meet the various requirements of the industry.

A principal object of this invention is to provide an improved straightening and contour correcting machine which may be quickly adjusted for use with any one of a large number of sectional shapes of various alloys.

Another object of this invention is to provide an improved roller straightening and contour correcting machine in which the roll pressure applied for straightening or correcting contours of a section is independent of the pressure required to drive the section through the machine.

A further object of this invention is to provide a straightening and contour correcting machine which does not mar the surface of the section being processed thereby;

An ancillary object of this invention is to provide an improved straightening and contour correcting machine which can be rapidly adjusted to accommodate sections having a variety of shapes.

In order to straighten and correct contours of sections in the proper way, a machine used for these purposes must perform the following main functions:

(1) It must force the section through the machine.

(2) It must bend and form certain portions of the shape to the required configuration; for example, bend flanges or webs into proper angularity.

(3) It must bend the workpiece lengthwise in order to effect straightening.

(4) It must be capable of applying correcting pressure and corresponding counter support on the section from any direction.

These four basic functions require that such a machine be capable of applying the necessary forces to the workpiece and of counterbalancing the reactive components of force resulting from the applied forces.

It must furthermore be taken into consideration that the pressure required for one of the four functions may be different from the pressure required for another. The force required'to bend a thin potion of the section into proper alignment will certainly be smaller than the force required to bend a heavy section.

correcting or straightening is applied. In addition, the pinching pressure must never interfere with the other functions, at least not adversely. Pinching pressure must not superimpose additional stresses on the stresses set up by the correcting or straightening procedure and must, therefore, be applied a sufficient distance from 'the zone to be straightened or corrected.

Pinching pressure must be applied in a way that any local rolling mill effect causing critical degrees of deformation is avoided. Such eflect would be undesirable, particularly on certain magnesium and aluminum base alloys.

For very thin-walled and bulky shapes, pinching pressure and any corrective forces must not be exerted in a way that the shapes or portions of them would tend to collapse.

Under certain circumstances, it may be desirable that the pinching pressure he applied not by rolls made from rigid, inelastic materials, but by rolls made from or covered with elastic material.

The machine must, furthermore, allow for arranging the rolls in a way that rubbing or milling machine effect caused by differences in circumferential speed of the rolls is positively avoided.

The rolls must be arranged in such a way that the corrective forces and the reactive counter-support represent the most effective couple of forces with respect to the desired corrective deformation.

The machine must allow for applying pinching roll diameters different from the correcting or straightening roll diameters.

In order to straighten or correct sections of comparatively narrow and semi-closed configuration where there is not enough space to countersupport or to apply the corrective pressure by means of rolls, the machine must be of a design to use combinations of rolls and corrective tools of non-rolling nature.

The tool stands must be of a design that forces and counter-forces, preferably more than three, can be applied radially on one cross-section of the shape. This means normal to the length axis of the shape in one plane. The forces and counter-forces to be applied in this plane in any combination of directions from zero to 360.

In accordance with this invention there is provided a metal working device comprising a plurality of pinch roll assemblies, a section straightening assembly and a contour correcting assembly, each of said assemblies being disposed along and around a common center line in working relationship with respect thereto. One of said pinch roll assemblies precedes and follows each of said other assemblies. The straightening assembly comprises a plurality of tool retaining rings, each of the rings being axially aligned with respect to the others and secured to a. ring mounting structure. The ring mounting structure of each of the rings is slidably coupled to a common base member. Each tool retaining ring has a tool holder coupled thereto, the tool holders including a radial movement mechanism and means for moving the tool holder towards and away from said centerline. The contour correcting assembly comprises a plurality of annular tool holding rings each perpendicularly disposed with respect to the centerline in spaced apart side by side relationship with respect to each other. Each of the tool holding rings has a mounting member which is secured to a common base member and has at least one tool holder secured thereto, each tool holder being adapted for moving a tool held therein in at least 3 directions.

The invention, as well as additional objects and advantages thereof will be apparent when the following detailed description is read in connection with the accompanying drawings.

Figs. 1 through 8 illustrate, in simplified form, various straightening, contour correcting, and pinch roll arrangements which may be achieved by the difierent sections of the straightening and contour correcting machine of this invention; in which:

Fig. 1 shows the disposition of contour correcting rollers for straightening a distorted'flange of a U section, with auxiliary rolls positioned above and below the channel section to maintain the balance of forces;

Fig. 2 shows the disposition of rollers for straightening along the X axis of a U" section;

Fig. 3 illustrates a roller, straightening arrangement for straightening along the Y axis of a U section;

Fig. 4 illustrates how the pinch rolls are applied to a U section to force the section through the roller arrangements of Figs. 1, 2, and 3;

Fig. 5a illustrates the roller arrangement for straightening a bent leg of an angular section, and

Fig. 5b shows how the pinch rolls are applied to such a section;

Figs. 6a and 6b illustrate the application of rollers to correct warping along the X axis of the section shown in Figs. 5a and 5b'.

Fig. 7 illustrates a roller arrangement for correcting the contour of a section having semi-circular crosssection;

Fig. 8 illustrates the application of pinch rolls to the semi-circular section shown in Fig. 7.

Fig. 9 illustrates the use of a sliding tool in combination with stabilizing rollers for correcting the contour of an angular section which is too narrow to permit the use of a roller for contour correction;

Fig. 10 is a plan view taken along the line 10-10 of Fig. 9;

Fig. 11 is an elevational view showing a modified sliding tool which is adapted to be used in the arrangement shown in Fig. 9;

Fig. 12 is a side elevational view of the roller straightening and contour correcting machine of the invention;

Fig. 13 is a plan view of the machine shown in Fig. 12;-

Fig. 14 is a side elevational view, partly in section, of a contour correcting ring of the machine shown-in Fig. 12; and

Fig. 15 is an end elevational view partly in section, of the ring and tool holder shown in Fig. 14.

Fig. 1 illustrates the use of the roller straightener of this invention as applied to a channel section, indicated generally by the numeral 20, having a leg 22 which was distorted prior to passing against the roller 24. The corrective force, designated P is applied through the roller 24 while counter-supporting forces P and P are applied through rolls 26 and 28, respectively. Auxiliary rolls 30, 32, indicated in broken lines because they lie in another plane than do the rolls 24, 26, 28, are used to hold the section in the correct general position for making the correction of the obliqueness of the leg 22.

None of the rolls 24-32 are used as pinch rolls. Fig. 4 illustrates the use of large pinch rolls 34, 36 which may be used in connection with the channel section 20. Such an arrangement of pinch rolls permits wide contact with the section 20, resulting in little or no defacing of the section 20 as it is drawn through these rolls.

Fig. 2 illustrates the use of the roller straightener of this invention to straighten the channel section 20 following the correction of the contour of the section 20 as shown in Fig. 1. Channel sections will either be warped or bent over the vertical or horizontal axis of the section. Fig. l2 illustrates a roller arrangement for straightening the section along its horizontal axis. Pairs 38, 40 of rolls are provided for hearing against the web 42 of the section 20 adjacent to the flanges Z2, 44. A large roller 46 is disposed below the section 22, bearing against the section. Several sequences'of rolls 38, 46 and 40 may be required to straighten the section. Further, in order to prevent the buckling of the flanges 22, 44, sets 48, 50 of stabilizer rolls are often provided. A pinch roll arrangement of the type shown in Fig. 4 may be used to pull or drive the'seetion'20 through the straightening rolls.

Fig. 3 shows a roller arrangement which may be used to straighten the section 20 around the vertical axis; In Fig. 3 two pairs 52, 54 of supporting rolls and one pair 56 of bending rolls are shown. One pair 58 of stabilizer rolls are provided to prevent buckling of the section under the large bending pressures which may be described.

Figs. 2 and 3 show, when compared with Fig. 1, that straightening and contour correction are different types of operations.

Figs. 5a and 5b show the correcting roll-arrangement for an angular section, indicated generally by the numeral 56 of which one leg, shown in broken lines, requires an angularity correction. The section '56 is an example of a group of extruded sections having cross sectional configurations which may not be corrected in conventional roller straighteners. Four rolls, '58, 60, 62, and 64, are required to correct the angularity of the leg 66 of the section. Fig. 5b shows the positioning of the pinch rolls 68, 70 which are required to force the section 56 through the angularity correction roll arrangement of Fig. 5a; Only the roller 62 is used to correct the angularity of the leg 66. The rolls 5-8, 60 and '64 are counter supporting rolls.

Fig. 6a is a cross sectional view taken along the line 6a6a of Fig. 6b. The roller arrangement shown in Figs. 6a and 6b is adapted for straightening sections which are warped with respect to the horizontal axis of the section, indicated generally by the numeral 72. The bending is done by the rolls 74, 76, 78 and the section 72 is supported by rolls 80, 82. The bending pressure is exterted by three rolls in order to minimize any local deformation of the surface structure of the metal. As seen in Fig. 6b, the rolls 74, 76, 78 are disposed about midway between the supporting rolls 80, 82.

Fig. 7 shows a contour correcting arrangement for a semi-circularly shaped section. In Fig. 7 the roll '84 exerts the pressure for correcting the warped section 86 (shown in dotted lines) while rolls 88, 90 are the counter supports.

Fig. 8 shows that each upper pinch roll 92 and lower pinch rolls 94, 96 has an elastic rim 98, 100, 102 respectively, which apply evenly distributed pressure to the section 86.

While in the previous examples corrections of the contour of the sectionshas been accomplished by means of rollers, tools which are adapted to slide along the section to be corrected may also be used. Figs. 9 and 10 The use of a sliding tool, such as the tool 110, for example, is of particular advantage for use with sections which are too narrow to permit the use of rolls. While the sliding tool 110 is used in the arrangement of Figs. 9 and 10 to correct the contour of the section, sliding tools may also be used as counter supporting members for the section to be straightened or otherwise corrected in shape.

Using a sliding tool may result in the marring of the surface of the section it contacts unless special p'recautions are taken. Some lubrication between the section and sliding tool may be necessary. Cooling of the sliding tool (or section) may likewise be necessary in order to prevent scoring which occurs at elevated temperatures. All of the section-contacting surfaces of the sliding tool should be highly polished. Materials which may be of use inmaking sliding tools for use in this invention are steelsof 'various types, including hardened and chrome plated steels; zinc alloys; graphite; graphite-iron sintered forms, hard wood blocks, or plastics. The type of material to be used to make a sliding tool depends on the presto correct in one pass, warpage of the section 124 which sure to be applied, "the space available, the curvature of the surface where'the pressure is to be applied, the degree of diificulty of the correcting work to be done, and the quantity of sections to be straightened.

Fig. 11 shows a combination of roll and sliding tool. Such a tool, in certain cases, may prove to be very useful in minimizing the bearing load on the main part of the sliding surface and may prevent scoring which tends to occur on the first onethird of the bearing length. The lead roll 120 may, for example, be a ball hearing. The sliding tool part 122 may otherwise be of the type shown in Figs. 9 and 10. Such a combination tool is often used otherwise would require two or more passes.

Figs. 12 and 13 show apparatusv for combining the functions of the roller arrangements shown in the previous figures, namely driving, contour correction and straightening of the work section. The apparatus, indicated generally by the numeral 126, comprises a section straightening assembly, indicated generally by the numeral 128, a contour correcting assembly, indicated generally by the numeral 130, and three drive or pinch roll assemblies indicated generally by the numerals 132a, 132b, and 1320 respectively. The drive roll assemblies it may be seen, precede and follow each of the other assemblies 128 or 130.

Each of the pinch roll assemblies 132a, 13211, and 1320 are identical as illustrated, but may be of different structural design so long as the same functional relationship is retained. As shown, the roll assembly 132a comprises a supporting frame 134, a fixed lower spindle 136, an upper spindle 138 which may be raised or lowered with respect to the spindle 136 and which is axially aligned with respect to the spindle 136. The upper or movable spindle 138 is journaled in and supported by a slidable member 140 which is carried by the supporting frame 134. Hydraulic jacks 142, secured to the upper part of the framing member 134, are coupled to the slidable member 140. An electric motor 144, or other suitable power source, is coupled to the spindles 138 and 136 through a suitable gear box 146. Pinch rolls 148, are secured to spindles 136, 138 respectively.

The section straightening section 128 includes a base 152 having a track section which carries a plurality of ring-like tool supporting members, indicated generally by the numeral 154, which are secured to base sections 156. The base sections 156 are often supported on the track section of the base by rolls 158 which permit easier positioning of the tool supporting members 154 along the base 152. When in operating position, however, the base sections 156 are usually bolted to the base 152.

Each of the ring-like tool supporting members 154 used inthe section straightening section 128 is adapted to have attached thereto one or more tool holders 160. Usually, two to five tool holders are attached to each tool supporting member 154. Figs. 12 and 13, for the sake of simplicity, show only two tool holders.

The ring part 1620f each ring-like tool supporting member 154 comprises an annulus having a circular stiffening section extending outwardly from one side thereof. Each member 154 is, as illustrated, the same as one tool holding ring 164, shown in Figures 14 and 15, which will be described in detail later.

Referring to Figs. 14 and 15, as well as to Figs. 12 and 13, the contour correction assembly 130 includes a pair of tool holder rings 164 which have supporting structures 166 by which they are secured to a base 168. A tool holder 184,which is shown in detail in Figs. 14 and 15, is secured to each side of the tool holding ring '164.

Each tool holding ring164 comprises two flat annular sections 172, 174 which are disposed in parallel with respect to each other and are joined by a Web section176. The ring 164 has a generally H-shaped transverse crosssectional configuration. The inner rim 178a (and 17812) of the ring 164 is circular and is provided with gear teeth 180 around the entire length of the rim. The outer rim 181 of the ring 164 is circular and concentric with respect to the inner rim 178.

The tool holding rings 164 and tool supporting members 154 are disposed parallel with respect to one another and perpendicular to a common center line 182 which extends longitudinally thnough the machine (see Figs. 12 and 13).

The tool holder shown in detail in Figs. 14 and 15, and indicated generally by the numeral 184, includes a body or base part which has a channel section 186 along most of its length and an end section 188 of L shaped longitudinal cross-sectional configuration which has a bore 190 therein. The channel section 186 has grooves in the channel walls (indicated by the dotted lines 192 in Fig. 15) which are parallel to the web or bottom part of the channel section.

A clamp 194 is secured to the end section 188, holding the end section 188 against the flat side surface of the annulus 172. Attached to the side wall of the channel section 186 near the inner periphery 178a is a clamp and base positioning device. The clamp and base positioning device includes a lrousing 196 and base retainer 198 and a pair of plates 200 which extend from the side of the housing. The base retainer 198 and plates 200 have axially aligned bores in which a shaft 282 is journalled. The housing 196 contains a worm 204 having a drive end 206 which extends from the housing. The worm'204 engages a gear 208 on shaft 292. A smaller gear 210 on shaft 202 engages the gear teeth 180 of the inner rim of the annulus 172.

Thus, by turning the drive end 206 of the worm 204, the tool holder 184 may be moved radially around the ring 164 by causing rotation of the gear 210 with respect to the gear teeth 180.

A slidable member 212 is disposed in the channel.section 186, engaging the grooves 192 in the channel walls. Longitudinal movement of the member 212 is controlled by the threaded bolt 214 which is coupled to a drive wheel 216 by means of the shaft 218, gear 220 and the drive gear 222. The threaded spindle 214 passes through the bore 190 in the end section 188 of the base part. The other end of bolt 214 is coupled to the member 212. At the end of the member 212 which is nearest to the center line 182, a rotatable member 224 having a grooved channeled surface and an arcuate surface is coupled to the member 212 by a shaft 226. The arcuate surface is provided with gear teeth 228. A worm 230 disposed in the member 212, engages the gear teeth 228. When the drive head 232 of the worm 230 is turned, the radial position of the rotatable member 224 is changed,

A tool mounting bracket 231 is disposed against the grooved channeled surface of the member 224. The bottom of the bracket has rack gear teeth 233. A worm 234, disposed in the member 224, engages the gear teeth 233, permitting lateral adjustment of tool mounting bracket with respect to the member 224. A tool 236 is mounted on the bracket 231.

From the above description it may be seen that the tool 236 may be moved radially around the annulus 172, moved in and out with respect to the centerline 182, again adjusted radially and finally adjusted laterally. Thus, using tools of the type shown in Figs. 14 and 15 or in any of the previous figures, the ring 164 and tool holder 184 permit the correction of contour of any desired type section which passes through the contour correcting section 130. In practice each tool holding ring 164 usually carries two to five tool holders 184 on each annular section 172, 174.

While tool holding rings 164 may be and often are used in the section straightening assembly 128 as well as in the contour correction assembly 130, the straightening assembly 128 does not require a tool holder with all the tool positioning adjustments which are available in the tool holder 164. A tool holder capable 'only of being moved i'adially around the tool supporting members 154 and adjustable with respect to the center line 182 is all that is required of tool holders in the straightening section 128.

In the contour correcting assembly 130, the distance between the tool holder rings 164 may be, if desired, changed by sliding the rings 164 along the base 168. However, there is much less changing of that position in preparing the assembly for work on various sections than occurs between the various tool supporting members 154 of the section straightening section.

In operation, a section to be contour corrected and straightened is fed through appropriate pinch rolls 148, 150 of roll assembly 132a, is acted upon by suitably positioned straightening tools in the tool holders 160 in the straightening section 128, passes through suitable pinch rolls 148, 150 of roll assembly 132b, enters the contour correcting assembly and is acted upon by the tools in the various tool holders 184 of that assembly, and finally passes through the rolls 148, of the pinch roll assembly 132c before leaving the apparatus 126.

The apparatus 126 may be used on hot sections immediately after extrusions or is equally well adapted for cold working of the sections. It may be seen that the combination of tool holder rings 164 and tool holders 184 and appropriate tools permits the correcting of contour of an extremely wide variety of types of sections passing through the apparatus 126. Such corrections could not be made by conventional roller straighteners. Further, the apparatus 126 may be rapidly adjusted to be used in processing any specified section. Also, since the functions of driving, straightening and contour correcting are separate and distinct, scuffing or marking of the sections as they are straightened is virtually eliminated.

I claim:

1. A metal working device comprising a plurality of pinch roll assemblies, a section straightening assembly and a contour correcting assembly, each of said assemblies being disposed along and around a common center line in working relationship with respect thereto, one of said pinch roll assemblies preceding and following each of said other assemblies, said straightening assembly comprising a plurality of tool retaining rings, each of the rings being axially aligned with respect to the others and secured to a ring mounting structure, the ring mounting structure of each of the rings being slidably coupled to a common base member, each tool retaining ring being axially movable with respect to each other tool retaining ring and to the pinch roll assembly and contour correcting assembly, each tool retaining ring having a tool holder coupled thereto, said tool holders including a circumferential movement mechanism and means for moving said tool holder towards and away from said center line; said contour correcting assembly comprising a plurality of annular tool holding rings each perpendicularly disposed with respect to said center line in spaced apart side by side relationship with respect to each other, each of the tool holding rings having a mounting member which is secured to a common base member, each tool holding ring having at least one tool holder secured thereto and each tool holder having means for moving a tool held thereby in at least three distinct manners of movement.

2. A contour correcting and straightening assembly comprising a plurality of annular tool holding rings each perpendicularly disposed with respect to a center line in spaced apart side by side relationship with respect to each other, each of said tool holder rings having a separate mounting structure which is slidably secured to a common base member which is aligned with respect to said center line, each ring including a pair of parallel disposed annular plates joined by a web part, a peripheral surface of each plate having gear teeth extending therearound, a plurality of tool holders, at least one tool holder being slidably secured to each of said plates, means engageable with said gear teeth for moving each holder radially around the periphery of each plate, said tool holder comprising a channeled body having a web surface between its channels, said channels each having a groove disposed parallel to said web surface with the grooves facing one another, a slidable block having a tool end, said block being disposed against the web surface of the channeled member,

' said block having keys extending therefrom which mate with said grooves, means for positioning said slidable block at a predetermined position along said channeled member, a pivotal member being coupled to said tool end of the slidable block, said pivotal member being radially movable in a plane substantially parallel with the periphery of said ring, and a slidable tool retaining element,

said tool retaining element being coupled to said pivotal 2,321,936 Pollock June 15, 1943 2,458,906 Himmel Jan. 11, 1949 2,505,241 Gray et a1 Apr. 25, 1950 2,539,107 Sectish Jan. 23, 1951 2,642,115 Van Hufiel June 16, 1953 2,708,511 Wilson May 17, 1955 2,843,178

Nighthart July 15, 1958

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