US3236079A - Control device for metal straightening machine and a method for operating such machine - Google Patents

Description

F. UNGERER Feb. 22, 1966 CONTROL DEVICE FOR METAL STRAIGHTENING- MACHIN AND A METHOD FOR OPERATING SUCH MACHINE Filed June 15, 1961 HH l lNVENI'OP F/?/ 72' UN ERER BY mWcwu I Mw United States Patent 3,236,079 CONTROL DEVICE FQR METAL SGHTENING MACHINE AND A METHOD FOR OPERATING SUCH MACHINE Fritz Ungerer, Arlingerstrasse 6, Pforzheirn-Brotzingen, Germany Filed June 15, 1961, Ser. No. 117,310 1 (llaim. (Cl. 727) This invention relates in general to sheet metal working machines and in particular to a new and useful device and method for determining the irregularities in a piece of sheet metal for use in connection with the programming or arrangement of straightening rollers in a straightening machine for the purpose of straightening the sheet metal irregularities.

The invention has particular application for use in association with the straightening machine of a type which includes straightening rollers which are rotatably supported at each end and supporting rollers intermediate the lengths of the straightening rollers which adjustably bear against the straightening rollers to effect elastic bending of the rollers at specified locations to effect a change in dimension between the next adjacent group of straightening rollers for the purposes of applying bending forces to the piece of sheet metal fed therebetween for the purposes of correcting irregularities therein. Such machines generally include an upper and a lower group of straightening rollers, each of which may advantageously include adjustable support rollers which effect dimensional changes at laterally spaced locations between the upper and lower straightening roller groups. Generaly, however, it is sufiicient if only the supporting members of one of the groups, preferably the lower group, are made adjustable. Overall upward adjustment may be accomplished by raising the upper roller group, while overall adjustment downwardly may be accomplished by lowering the entire upper roller group.

With machines of this character, it is necessary to set the individual supporting elements in a manner along the width of each roller group in a particular pattern to correct the irregularities of a sheet to be straightened which is to be fed between the roller groups. Since sheets which are rolled have varying types of irregularities, it can be seen that it is essential to adjust the complete straightening machine to effect the desired working on the sheet metal to correct the irregularities in the places where they occur.

In accordance with the present invention, means are provided to effect adjustment of the supporting members for the straightening rollers automatically in dependence on the nature of the sheet which is to be straightened. The machine is designed for operation upon sheets which have a substantially uniform consistency, such as would be produced by a rolling mill. Rolled sheets of this nature have different wavy or corrugated characteristics in different regions along the widths of the sheets. Because of the waviness produced at various locations on the sheet, the length at particular spaced locations across the width will vary. For example, some sheets have a smooth stretch in the middle and are corrugated on the edge portions, or vice versa. Sheets are also produced which include corrugated portions running alternately over the widths of the sheets.

The straightening of the regions of the sheet which have shortened areas, so that the corrugations in these regions will disappear is accomplished in a straightening machine which is dissimilar from a rolling mill wherein the sheets are squeezed. In a known straightening machine, a sheet is bent to and fro when the sheet passes between the straightening rollers of the upper and lower groups. At those areas where the straightening rollers are bent out by the adjustment of their supporting members or rollers, the amount of inter-engagement between the roller groups is varied and, hence, the to and fro bending effected on the sheet is changed, so that a more intense straightening action can be exerted on the shorter longitudinal stretches than on the other stretches.

The supporting elements for a straightening machine are generally rotating supporting elements, that is, rollers or short rolls whose mountings bear against a rigid support surface which, in some instances, is adjustable. Instead of rotating supporting members, it is also possible to use supporting members on which the straightening rollers glide. Such supporting members would then be in the manner of a gliding or varying dish. It is also known to employ support elements in the form of neck bearings.

In accordance with the present invention, means are provided for automatically sensing the irregularities of a sheet at spaced locations across the width and along the complete length thereof.

In accordance with a preferred arrangement, means are employed, such as graphical indicating means, for recording indications of sheet waviness so that the information can be fed to a programming device for setting the supports of the straightening machine.

In accordance with another arrangement of the invention, means are provided for directly actuating control elements for setting the support elements of the machine, so that the sheet, after it is sensed, may be immediately placed in the machine for operation thereon. Such an embodiment may include an arrangement of contact elements which actuate control circuits operating a drive means, such as a motor for adjustably positioning the support elements.

In accordance with a further aspect of the invention, means are provided for effecting the feed-in or storing of the information into control relay circuits, so that the information may be continuously fed to means for adjusting the support elements of the straightening machine to effect the desired positioning of the rollers for working upon the sheet to be straightened.

The sensing device advantageously includes a frame member having one or more sensing means disposed across the length thereof, which may be electrical or mechanical devices. Means are provided for shifting the frame member along the length of the sheet and for simultaneously recording the information on a continously moved graphical recording medium.

In accordance with a preferred method of the invention, the automatic adjustment of the supporting elements of the straightening machine, starting from a position which corresponds to the narrowest distance of the straightening rollers and proceeding in a direction toward the enlargement of this distance between rollers, is performed by adjusting the supporting elements of the lower straightening rollers by lowering the supporting elements.

Accordingly, it is an abject of this invention to provide an improved method for sensing irregularities in sheet material.

A further object of the invention is to provide an improved method for sensing irregularities in sheet material and for employing the information in the operation of a straightening machine.

A further object of the invention is to provide a device for automatically sensing the irregularities along the width of a piece of sheet metal.

A further object of the invention is to provide a device for obtaining an indication of the irregularities of a piece of sheet metal at spaced locations along the width and extending along the complete length thereof and for employing the indications of such irregularities for operating a straightening machine, including displaceably'mounted rollers which are displaced in accordance with the irregularities sensed in order to counteract such irregularities.

A further object of the invention is to provide 'a-device for sensing the irregularities along the length of a-piece of'sheet metal including a sensing means arranged to ride over the sheet and'having indication means thereon, and means for moving a sheet of graphmaterial past the sensing means for obtaining an indication thereon as said sensing means is moved the complete length of said sheet material.

A further object of the invention is to provide a sensing device for indicating the irregularities along the length and width of sheet'material and which is simple in design, rugged in construction and economicalto manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and desc'riptive matter in which there is illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a schematic transverse view of the straightening rollers and the independent means for displacing portions ofthe rollers intermediate their width toeflfec-tthe desired straightening action on sheets fed therebetween;

FIG. 2 is a somewhat schematic perspective view of a device'for sensing the irregularities in sheet metal;

FIGS. 3 and 4 are schematic representations of de-. tails of modifications of the sensing means indicated in FIG. 2.

Referring to the drawings in particular, the invention embodied therein is provided for the controlled operation of a straightening machinegenerally designated 40'. The straighteningmachine 40includes 'an upper straightening roller group, the peripheral surfaces. of which are indicated a and a lower group, the upper surfaces of which are indicated b. Bearings 42 at each end of the upper roller groupa support these rollers against forces which emanate from below and bearings 44 located at each endof the lower straightening roller group b support these rollers against forces which emanate from above. The straightening. rollers a are'contacted by or supported by spaced supporting elements or pressure rollers c which,

in turn, are supported in bearings 46 which prevent upward displacement of the rollers.

In a similar manner the lower straightening rollers. b-

are supported or contacted by a plurality of laterally spaced supporting rollers d which are mounted in constructional elements e which, by meansof spindles f, can be adjusted as to height. By raising or lowering the constructional' elements e carrying. the rollers d, it is possible to elastically deform or bend the straightening rollers b as indicated by the curved portion inFIG. 1 on an exaggerated' scale; In actual practice, only very small adjustments are made,- but the indication on the drawing has been exaggerated so that it may be more clearly illustrated.

At those areas where the lower straightening roller b is deformed upwardly, the nip formed between the upper rollers a and the lower rollers b is tighter or narrower so that in each area the stronger to and fro bending of the plate positioned between the rollers takes place. This type of adjustment is suitable for those regions of the metal sheet which are too short in the sheet length and therefore in the form of smooth regions or areas which are adjacent to corrugated or overlengthed sec tions or stretches of sheets.

In FIG. 2 there is indicateda sensing device generally designated 48 which is arranged to provide a programming for the operation of the straightening machine 40. The sensing device 48 includes frame elements 2 supporting a feed table 1 onto which sheet 3 to be straightened is placed. "In the embodiment indicated, a plurality of longitudinal sensing lines 4 are indicated at spaced locations across the width of the sheet to show the designations of the locations which are sensed for the purposes of straightening the sheets :in the straightening machine 40.

At eachside of the table top 1 there are provided channel-shaped side rails 5 and 6 along which are slidable block members 50 and 52 which carry vertical support members 7 and 8. The support members 7 and '8 are interconnected by cross member 9 to form a rigid frame. On the support 8 there is secured a body 10 having internal threads which are in engagement with a rotary threaded screw member 11 which is rotated by drive means 12 to move the frame, including supports 7 and 8 and transverse member 9, backwardly and forwardly along the length of the table top 1.

The support member 8 is hollowed at its upper end to receive a downwardly extending shaft of a drum 14 having a gear (not shown) which engages teeth portions on the upper edge of the channel 5 so that the drum 14 is rotated in timed relationship to the longitudinal displacement of the frame along the length of the table top 1. Another drum 13 is rotatably mounted on the upper end of the support 9 and a recording graph or graph carrier 15 of sheet material is stretched therebetween and moved from the drum \13 0I1t0 the drum 14 during movement of the frame along the length of the table and the sheetG positioned thereon;

A power drive means 12 is indicated at the location of one end of the table top 1, but it may be located in any suitable manner. For example, it may be located in such a manner that each side of the frame driving elementsv are engaged which can be embodied by chain drives or rope drives.

In accordance with the invention, the cross member 9 carries a plurality of sen-sing devices, one of which is indicated 16, which moves along the surface of the plate 3. In the embodiment indicated, the sensing device 16 is mechanical in nature and includes a rod member which is reciprocated in an opening provided in the support member 9. The rod member carries a collar 18 which is biased downwardly by a compression spring 17 interposed between the collar 18 and the support member 9. The lower end of therod is provided with a forked portion 19 which carries a roller 20 which is moved in contact with the plate 3 along each of the, sensing paths 4. Movement in this manner will cause reciprocation of the rod 16 in accordance with the irregularities on the sheet 3. The upper end of the rod is provided with a stylus or indicating instrument 21 which, in the embodiment illustrated, is arranged to record graphically on the graph carrier 151the irregularities on the sheet. For clarity of illustration purposes, only one sensing device has been indicated, but it should be appreciated that a number of sensing devices equivalent to the number of sensing paths 4 areprovided.

The arrangement is such that the ratio of the speed of the frame carrying the sensing devices with regard to the speed of the graph carrier 15 is adjustable. In those instances where the graph carrier 15 is a paper strip, then the indicating means 21 is a writing pin. It can be seen that since the writing pin records irregularities and since the graph carrier is moved, a curve of the irregularities is plotted. In a preferred arrangement, the indicating means are arranged at different levels, so that successive indications across the width of the sheet 3 are made at various level indications on the graph carrier 15. Instead of a writing instrument, the indicating means may comprise electrical sensing means, such as a photoelectric cell, and the graph carrier 15 may be a lightsensitive film. In some instances, it is desirable to use invisible light and the graph carrier may be sensitized for the respective kind of light used, so that it will not be necessary to shield the carrier due to the light at the location of the test. In some instances, the region of the graph carrier is blackened with particular writing in the same manner as a sound strip of a sound film, such as by a zig-zag writing so that the completed graph carrier can be sensed the same as a like sound film.

In accordance with one process, the graph carrier is transferred by programming arrangement for operation of the straightening machine 40, the programming being such that the supporting structures e corresponding in location to the trace path 4 will be actuated in the same manner as the indications on the graph. In some instances, the irregularities which are sensed, either mechanically, optically or electrically, are utilized for adjusting a time relay, the running time of which determines the feeding of the electric motor or similar electric motors which adjust the supporting elements e or supporting rollers d pertaining thereto.

In FIG. 3 there is indicated an embodiment in which no intermediate carrier 15 is employed, but the sensing apparatus is utilized for the direct actuation of the support elements e for the adjustable roller means d for the straightening machine 40. In this embodiment, the sensing device, depending upon the corrugations or irregularities sensed, gives direct pulses to an adjusting motor of one or several motors for the supporting elements 2. For this purpose, a sensing roller is mounted on a lever 22 which is rockable about an axis 24. A push rod 26 is connected to the lever 22 by means of a pin 25. The push rod 26 carries a slide contact 27 which slides on a rail 28 which carries a plurality of contact elements 29 which are separately connected to individual motors (not shown) or controls therefor.

Dependent upon the up and down movement of the lever 22 in accordance with the irregularities sensed, the contact 27 will contact a varying number of contacts 29. When contacted, the contact elements 29 release a short current pulse for the adjusting motor which sets the support elements e.

In FIG. 4 there is another embodiment which provides a great deal of accuracy in the setting of the means for operating the straightening machine 40. A rod 26, corresponding to the rod 26 in FIG. 3, provided with gears which mesh with a pinion 31 which is rotatable about an axis 32, and also with a pinion 33 which is rotatable about an axis 34. One of the two pinions 31 and 33, respectively, is driven when the rod 26 is lifted, while the other one is driven when the rod 26 is lowered. These pinions 31 and 33 are advantageously provided with side gear teeth which contact rack members 54, 56, which carry an element 58 and 60, respectively, which effects adjustment of a time relay (not shown). In the arrangement shown, one of the pinions runs freely While the other one drives so that the up and down movements of the rod 26, in accordance with the irregularities which are sensed, are stored in the time relay. For the time relay, a running adjustment of the motor for making adjustments of elements e is achieved.

It is advantageous to sense the sheet 3 again after it is passed through the straightening machine 40, so that accurate resettings may be made to avoid excessive straightening and insure that the lowest number of passages through the machine will yield the desired straightening extent.

After the automatic adjustment of the individual supporting elements 2 of one group of straightening rollers, such as b, the straightening pressure at the inlet or entry end can be increased by moving the other roller group toward the first group, that is, moving the upper roller group a toward the group b. By decreasing the clearance between these roller groups, it is possible to cut down the number of passes through the straightening device which are necessary. Such a narrowing of the gap at the entry of the straightening machine 40 can also be accomplished automatically by causing the actuation of this adjustment in dependence on the difference between the sum of the absorbed pulses and the number of pulses which can be given off by the relay. When the entry pulses exceed, for example, twice or three times the giving oif capacity of the time relay, then the narrowing of the gap by moving one of the straightening rollers closer to the other group is automatically released.

By means of this apparatus of the invention and the method of first sensing the irregularities in a sheet metal, it is possible to straighten sheet metal very simply and easily. The experience of the operator of a straightening machine is not important with regard to the adjustment of the support elements of the straightening rollers. By means of the automatic programming or the automatic adjustment, the desired straightening extent is obtained after the sheet has passed through the machine one or more times.

In accordance with the invention, the sensing is performed while the entire sheet is outside of the straightening machine on a feed table which forms a support for the device, and has the advantage that any change in the corrugation of the sheet by means of tensioning, clamping or other deforming forces which may act on the end of the sheet and cause a false indication is prevented. Although it may be possible to bring the sensing and an automatic feeding of the sheet into the straighten ing machine into a time dependent relationship, it is generally more advantageous not to provide such a dependency and to perform the sensing independent from the feeding of the sheet into the machine. If a stack of sheets, by coincidence, should have been rolled with the same rollers then the sheets might be similar to such an extent that the sensing will give results which are in conformity within very narrow values. In such a case, those sheets which exhibit, after sensing, a very similar kind of corrugation, will be fed one after the other through the straightening machine after a single automatic transfer of the sensing results onto the machine adjustment and without feeding a new sensing result into the machine each time. The interposition of a plotting graph between the sensing of the sheets and the adjustment of the machine in dependence on this sensing facilitates the determination of any conformity of sensing and the proper arrangement of sheet groups which have similar corrugation values. The graph may be preserved and may be used at any given time for the automatic corresponding adjustment of the straightening machine.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

A process for the straightening of previously rolled metal sheets, having waviness due to previous working, in standard straightening machines having substantially flexible straightening rollers engaged by support rollers arranged at spaced locations transversely of a sheet for selectively bending the sheet to remove the waviness, said process comprising: sensing the waviness of the sheet along a plurality of laterally spaced paths extending along the sheet longitudinally with respect to its direction of movement through the machine, each path corresponding to a respective support roller; recording of the respective support rollers along the respective paths'to bend the sheet along the respective paths in a direction to remove the Waviness.

References Cited by the Examiner UNITED STATES PATENTS 2,219,163 10/1940 Maussnest 153106 2,264,725 12/1941 Shoupp et a1. 80-56.1 2,347,904 5/1944 Greuloch 15386 CHARLES 8; Winlock 1-53'86 Cozzo 8056 Ricks 73105 K rynytzky 153-'107 Reason 73l05 Maust 15386 Brucker 8056.1

FOREIGN PATENTS 4/1948 Great Britain.

W. LANHAM, Primary Examier.

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