US3268140A - Apparatus for guiding an advancing strip such as a strip of continuous sheet-metal - Google Patents

Description

Aug. 23, 1966 R. J. A. ROUYER 3,263,140

APPARATUS FOR GUIDING AN ADVANCING STRIP SUCH AS A STRIP 0F CONTINUOUS SHEET-METAL Filed May 6, 1965 5 Sheets-Sheet 1 Aug. 23, 1966 R. J. A. ROUYER 3,258,140

I APPARATUS FOR GUIDING AN ADVANCING STRIP SUCH AS A STRIP 0F CONTINUOUS SHEET-METAL Filed May 6, 1965 5 Sheets-Sheet 2 Aug. 23, 1966 R. J. A. ROUYER 3,268,140

APPARATUS FOR GUIDING AN ADVANCING STRIP SUCH AS I A STRIP OF CONTINUOUS SHEETMETAL Filed May 6, 1963 5 Sheets-Sheet 3 United States Patent APPARATUS FOR GUIDING AN ADVANQIING STRIP SUCH AS A STRIP 0F CONTINUOUS SHEET-METAL Robert Jules Auguste Rouyer, Levaliois-Perret, France, assignor to Societe Anonyme Heurtey, Paris, France Filed May 6, 1963, Ser. No. 278,245

Claims priority, application France, May 8, 1952, 896,834, Patent 1,330,780; Aug. 6, 1962, 906,147, Patent 82,128

9 Claims. (Cl. 226-18) It is known to guide advancing strip material in order to accurately locate its transverse position by mechanically sensing one of the edges of said strip by a sensing system operating on the transverse position of a receiving roll, for instance.

Such methods and apparatus cannot be employed in the case of fragile materials the edge of which must remain intact. Cases in point are strips of continuoussheet-metal that take the form of expanded coils subsequent to heat treatment and which it is desired to wind into tight coils having absolutely flat sides obtained by perfect alignment of the turns, such alignment being indispensable when the product is to be preserved in tightly wound coils, particularly during handling and transport.

An additional difficulty stems from the fact that the transposition is generally made from an expanded coil the associated former of which has a vertical axis, the sheet of metal following an upright path over a certain section before it reaches a receiving former for producing the tight coil, the axis of which former is likewise vertical. The guiding process must therefore allow for inevitable irregularities and for the effect of gravity, and at the same time preclude any contact with the edge of the product.

In order to achieve such a result, guidance of the strip in accordance with this invention is obtained by applying at least one roll against the strip and by adjusting the direction of the axis of the roll with respect to that in which the strip is travelling.

In one specific method of performing the invention, the edge of the strip runs through a position detector precluding any material contact, and the indications given by this detector are used to orientate the axis of the aforementioned roll.

The indications given by such a detection system and those given by a similar secondary detection system that detects deviations of the axis of said roll on the orientating member itself are caused to coact in balanced fashion, whereby to provide suitable damping of the orientating motion and thereby eliminate any hunting phenomena.

The present invention likewise encompasses such devices as permit of performing such a method and more particularly devices wherein the detectors consist of units comprising photo-electric cells and projectors, said cells being so adjusted that occultation of one half of their sensitive surface corresponds to the optimum travelling position of the strip and to the neutral position of the orientating roll.

Such simple and reliable devices permit of coiling the strip so that the sides of the coils are absolutely flat, irrespective of the material employed and the orientation of the plane of the strip relative to the direction of gravity.

Furthermore, in lines adapted to process such continuous strips, any marginal flaws on the treated strip are eliminated by effecting cuts along the faulty edge. Similarly, the widths of the strips inserted in succession along such lines tend to vary, thus leading to possible steps at the joining points of said strips.

Such cuts and steps might disrupt the adjustment process, in consequence whereof the present invention likewise has for its object to eliminate such disrupting influences without the need to exercise special supervision as the faulty parts run past.

To this end a threshold is fixed for operation of the motor regulating the roll, below which threshold adjustment can take place and above which all magnitude information ceases to operate.

Thus, the passage of a cut-out portion representing a variation in the straightness of the strip greater than the threshold value produces no effect.

The device for performing such an operating phase can comprise a relay interposed between the roll-displacing motor and its actuating amplifier, which relay is in turn controlled by a threshold-type amplifier placed in parallel with the normal control amplifier.

With regard to passage of the steps occurring at the joining points of strips of different widths, since the axes of the joined strips are coincident the steps must be symmetrical, and the position detector is therefore caused to be displaced in response to the information received by a pair of detectors which sense the band Width.

The apparatus for performing such an operating phase can comprise with advantage a position detector mounted on a moving carriage in conjunction with a first width detector and, on an opposite moving carriage, a second width detector, the two carriages being interconnected by a mechanism which moves them by equal and opposite amounts and operates in response to the sum of the in formation provided by the width monitoring detectors.

Thus, when a joint step runs past, the position detector reverts automatically and very rapidly to its straightrunning monitoring configuration.

The description which follows with reference to the accompanying drawings, which are filed by way of nonlimitative examples, will give a clear understanding of how the invention can be carried into practice.

Referring to the drawings filed herewith:

FIG. 1 shows a front view of a pinch-roll orientating mechanism partially cut away;

FIG. 2 is a top view corresponding to FIG. 1;

FIG. 3 is a schematic top View of the disposition of the component parts of a coiling line and of one of the possible locations of said pinch-rolls;

FIG. 4 is a diagram wherein a detection unit controls the orientation of pinch-rolls;

FIG. 5 shows an alternative arrangement;

FIG. 6 illustrates another alternative arrangement utilizing two orientating units;

FIG. 7 shows the wiring diagram of a balancing bridge with two photo-electric cells;

FIG. 8 is a diagram showing the form of regulation obtained;

FIG. 9 shows in schematic fashion the diagram of a regulating system into which is interposed a threshold amplifier, with a rupturing relay inserted into the adjusting motor feed circuit;

FIG. 10 is a highly schematic view of an arrangement of band-width monitoring carriages partially cut away;

FIG. 11 is a plan view corresponding to FIG. 10; and

FIG. 12 is a diagram of a regulating system operating on the band-width fluctuation detecting element.

Referring first to FIG. 1, the device shown therein comprises two brackets 1 and 2 facing each other and bearings 3 and 4 on the tops thereof, which bearings support journals 5 and 6 placed on either side of frame uprights 7 and 8. The bracket and frame elements are fabricated from welded sheet-metal forming hollow open-work boxes. Uprights 7 and 8 have their extremities connected to an upper cross-member 9 and to a lower cross-member 10 of similar construction.

Adjacent upright 7, cross-members 9 and 10 are provided with thrust bearings 11 and 12 between which extends the shaft 13 of a fixed roll 14.

Adjacent roll 14 is disposed a mobile roll 15 the extremities of the shaft 16 of which are mounted in thrust bearings 17 and 18, each bearing being provided with supporting lugs 19 slidably mounted in slide-ways in supports 20 rigid with the walls of cross-members 9 and 10, these slideways extending perpendicular to the direction of shafts 13 and 16.

The housings of bearings 17 and 18 are each connected, through the medium of an eye-lug and a shaft 21, to the terminal clevis 22 of the pushrod 23 of an actuator 24 the cylinder of which is pivotally connected via an eye-lug and a shaft 25 to a clevis 26 which is rigid with an end closure provided at the extremity of an extension on each of said cross-members. Thus the cylinders of actuators 24 and 27 provided at the two ends of shaft 16 can be connected in parallel to a single source of compressed fluid, whereby to apply pinch-roll 15 against roll 14 with equal force at both ends of shaft 16.

At one corner of the frame thus constituted, and more particularly at one extremity of cross-member 10, is provided a coupling clevis 28 adapted to be connected to eye 29 of the pushrod 30 of a mechanical actuator associated with a reduction gear 31 and a reversible electric motor 32, the casing of said actuator being supported by a shaft 33 the end journals of which are in turn supported in lateral bearings carried on brackets 34. Shaft 33 and the shaft passing through eye 29 and clevis 28 are parallel with journals 5 and 6.

The continuous strip running over roll 14 can thus be pinched between the latter and roll 15. Should the axes of these rolls come to be inclined under the action of motor 32, such action shifts the travelling strip in a direction and by an amount that depend on the direction and magnitude of the angle of inclination of the aforementioned frame.

To ensure correct positioning of one of the edges of the travelling strip, it will sufiice to control motor 32 in accordance with the indications provided by a sensing system.

In the specific case of FIG. 3, involving vertical-axis former 35 associated with a lower plate 36 adapted to receive an expanded coil 37 of sheet material, it is possible to dispose at the exit end of such a coil a fixed idler roll 38 over which, independently of the instantaneous coil diameter, a metal strip 39 is caused to run in a constant direction as it travels between two pinch- rolls 14 and 15 of the aforementioned type. The said pinch-rolls are placed ahead of a tautening block which possibly comprises, on the entry side, a roll 40 which presses against a roll 41 of fairly large diameter which is in turn associated with an exit roll 42 adapted to increase the amount of wrap of strip 39 around roll 41. Past roll 42, strip 39 is wound onto a vertical-axis forming roll 43 parallel to roll 35, on which strip 39 is butt-wound under tension. The shafts of formers 35 and 43, that of roll 41 and possibly also those of rolls 40 and 42 are powered, being driven and braked in any convenient manner whereby to ensure synchronized uncoiling and coiling.

At the exit end of expanded coil 37, pinch- rolls 14 and 15 can be so actuated in response to a mechanism monitoring the edge of the travelling strip as to adjust the level of the edge of strip 39 in such manner as to ensure that winding takes place without the edges of the tightly wound turns of the coil wound onto former 43 projecting from either side thereof.

To ensure symmetrical action, the axis of journals 5 and 6 is median. When the upper part of the frame is turned in the downstream direction of travel, strip 39 is shifted downwardly; conversely, when the upper part of the frame is turned upstream, strip 39 is shifted upwardly.

As shown in FIG. 4, idler roll 38 can be eliminated if pinch- rolls 14 and 15 impart an angular path to strip 39 between the point where it leaves expanded coil 37 and the point where it touches roll 41.

When such is the case, the pinching effect can in fact prove superfluous and the guiding system consisting of rolls 14 and 15 can be reduced to a single such roll, provided that the angular path followed by strip 39 causes the same to wrap to a sufficient extent around the remaining guide roll, as in the case of roll 15 in FIG. 4. Similarly, as shown in FIG. 4, a single sensing roll 44 is disposed on the exit side of tautening-block rolls 41 and 42, which sensing roll is located on the entry side of coil 43 and again provides an adequate degree of wrap. Such a single roll can likewise enter into an oscillating frame as hereinbefore described.

Referring next to FIG. 5, therein is shown a simplified system wherein the pinch-rolls 14a and 15a are positioned past the rolls 41 and 42 of a tautening block located directly at the exit end of coil 37, whereby to bring said pinch-rolls 14a and 15a closer to the coil 43 to be formed with uniformly aligned edges, the whole arrangement being such that these solitary pinch-rolls are placed as near as possible to the position where adjustment must be effective, i.e. near coil 43.

As is clearly shown in FIG. 6, provision can likewise be made between sensing roll 44 and the last roll 42 of the tautening block for a complementary idler roll 45 adapted to permit, where necessary, greater angular travel of said sensing roll 44.

The guiding rolls, and more particularly the motor 32 driving the same, can be actuated by any convenient nonmaterial sensing element activated by the edge of strip 39. Such a sensor could be a capacitive detector, an inductive detector or an optical detector. In the specific case of optical detectors, such a sensor would comprise for instance a projector and a photoelectric cell, the cell being disposed so that exactly one-half of its sensitive surface is masked from the radiation of the projector when the monitored edge of strip 39 is precisely positioned for normal uniform winding, the arrangement being such that operation takes place within the ranges of maximum functional sensitivity of such a sensor. Clearly, such projector-cell units can be variously positioned. As shown in FIG. 4, projector 46 and cell 47 could be placed at the exit end of the tautening block, for instance.

Reference is next had to FIG. 5, wherein projector 47a and cell 46a are disposed as close as possible to winding former 43; in FIG. 6, projector 47b and cell 46!) are placed ahead of the tautening block, whereby to control associated pinch- rolls 14 and 15. A further unit comprising a projector 46c and a cell 47c is positioned as close as possible to coiling former 43, whereby to control sensing roll 44.

In order to avoid any hunting phenomena, it is preferable in all cases to couple such a projector-cell unit monitoring the position of the edge of strip 39 to an equivalent detector monitoring the position of the frame supporting the guiding rolls, irrespective of whether the latter are pinch- rolls 14 and 15 or a sensing roll 44.

Such a monitoring unit preferably includes a projector and a cell identical to those monitoring the strip edge and cooperates with a masking screen (not shown) carried by the frame. Here again, said screen is so positioned that when the frame occupies a position exactly perpendicular to the direction of travel of strip 39, said cell is exactly half-masked.

As is shown in FIG. 7, cell 47 is disposed in one of the branches of a Wheatstone bridge, while the cell 48 monitoring the position of the frame occupies another branch thereof. These two branches are bothconnected to one of the terminals 49 of a current source. The other two branches are both connected to the other terminal 50 and comprise resistors 51 and 52. The first two branches comprising cells 47 and 48 have their extremities connected to those of resistors 51 and 52, and these common points are connected by leads 53 and 54 respectively to an amplifier 55.

The bridge hereinabove described constitutes a comparator generally designated by reference numeral 48a. Leads 53 and 54 feed an amplifier 55 which controls rotation of motor 32, which motor actuates the frame crossmember through its reduction gear 33. The position of the frame is monitored by cell 48, information from which is furnished directly to comparator 43a. The position of strip 39 at the exit end of the frame affects the position of the strip and the latter provides a feedback effect on the level of cell 47 by furnishing data that is superimposed on that which is provided by the position of the strip and transmitted by the latter to the output end 39a of the open coil, whereby the very material of the strip serves as an adding or subtracting comparator.

This system is schematically illustrated in FIG. 8, which clearly shows the nature of the slaved and damped servomechanism of the system. Such means permit obtaining faithful correction devoid of hunting, for when the monitored edge of the strip is in its average position, the rolls-frame is perpendicular to the strip centerline, the two cells 47 and 48 are half-masked, and the bridge 48a is in equilibrium. Should the monitored edge deviate, the degree of occultation of cell 47 varies, thereby unbalancing the bridge and starting up motor 32 in the required correcting sense until said bridge is balanced anew, such equilibrium being reached despite variations in the action of cell 48. A fresh position of equilibrium is obtained when motor 32 stops, but this is a position which is unstable due to the fact that action of the frame-roll subjects the strip to a transverse component tending to restore it to its average position. The strip shifts in the opposite direction and causes the occultation of cell 47 to vary, thereby producing a fresh unbalancing, a fresh start-up of motor 32 in the reverse direction, and a fresh variation in the action of cell 48, thus restoring the edge of the strip to the desired average position by a damped correction process.

It should be noted that the angle of oscillation of the frame corresponding to a given shift in the monitored strip edge can be adjusted to a value such that the corrective guidance provides maximum eifectiveness. To this end it will sufiice to accordingly adjust the lever-arm of the screen carried on said frame in relation to the frame pivots formed by journals 5 and 6.

Naturally, when a plurality of guiding systems is provided, regardless of whether pinch-rolls are utilized, whether the latter are brake'd or not to ensure proper tension Where necessary, or whether sensing rolls are employed, each system can include its'own amplifying detector, motor and compensator; similarly, a single cellprojector unit and a single amplifier could be provided to control oscillation of all the frames in parallel.

Manifestly, alternative control and damping methods could be employed.

As is clearly shown in the diagram of FIG. 9', wherein like components already described hereinabove are designated by like reference numerals, strip 39a issuing from a device adapted to adjust its position is monitored by a photo-electric cell 47 which is half-masked by the strip itself when the same is in its normal travelling position. Cell 47 is in point of fact of a bridge 4841 connected to an amplifier 55 controlling an electric motor 32. Through a reduction gear 31, motor 32 tilts the frame 10 supporting an adjusting roll, which roll is in turn adapted to displace the strip 39 sideways. The position of frame 10 is itself monitored by a detector 48 equipped with a photo-electric cell which is half-masked in the normal frame position and operates on bridge 48a.

Connected in parallel with amplifier 55 and identically activated by bridge 48a is a threshold-amplifier 55a which operates on a relay R actuating a contact C placed between amplifier 55 and motor 32.

With such a monitoring system, should the travelling strip embody a sudden indent (made to eliminate a flaw, say) in the monitored edge that detector 47 could confuse with a sudden lateral shift of the strip, the great amplitude of the effect of the indent on cell 47 will suddenly unbalance bridge 48a and cause amplifier a to operate. Relay R is then energized and contact C opened, thereby cutting off the current to motor 32 through amplifier 55 until the indent has travelled past, at which instant amplifier 55a ceases to energize relay R, contact C trips out and amplifier 55 resumes its function over motor 32.

As may be seen in FIGS. 10 and 11, a strip 39 may reveal, to a shift-detecting photo-electric cell, a change in width due to the end of said strip 39 being joined to a strip 39a of different width, with the two strips nonetheless retaining a common longitudinal axis.

In order to avoid the undesirable action that would result as the step, thus formed on the edge of the strip, passes cell 47, the latter is mounted on a suitably guided carriage provided with a projector 61 facing the edge of strip 39, which strip half-masks a photo-electric cell 62. The projector-cell unit is carried on the two branches of a carriage 60 which thus assumes a configuration in profile that can be likened to a C embracing the edge of the strip.

In addition to being guided on orienting slideways perpendicular to the axis of travel of the strip (such guidance not being shown), said carriage cooperates by means of a screw thread 63 with a screw 64 the axis of which is parallel with said slideways.

The opposite edge of strip 39 runs through a symmetrically designed carriage 60a, comprising a projector 61a and a cell 62a and cooperating by means of a screw thread 63a with a screw 64a of equal pitch and reverse thread to that of screw 64. Screws 64 and 64a have a common axis and are rigid with each other, being driven by a reduction gear 65 and a motor 66.

As may be seen in FIG. 12, cells 62 and 62a operate by addition in a bridge 67 connected to an amplifier 68, which amplifier in turn operates on a system 69 comprising a threshold detector and a polarized changeover relay. Said changeover relay controls the current supplied to motor 66, which in turn operates through its reduction gear 65 to modify the spacing between carriages 6t) and 60a. As represented by the line '70 on the diagram. of FIG. 4, such spacing provides feedback onto cells 62 and 62a.

In this way, when a step due to the junction of two strips of different widths runs past, cells 62 and 62a detect an unbalance transmitted by the chain hereinbefore described to carriages 60 and 60a, which'carriages are then displaced in the direction required to re-establish halfoccultation of said cells 62 and 62a by the edges of the fresh strip section 3%. For since the normal disposition of cells 62 and 62a corresponds to half-occultation, the sum of the current issuing therefrom will be constant under steady operating conditions.

When a mere sideways shift of a strip of constant width is involved, cells 62 and 62a being identical continue to furnish a constant sum of electric currents, since to each supplementary portion masked on one cell there corresponds a supplementary unmasked portion on the other cell. On the other hand, since cell 47 remains invariable in such cases, it operates in normal fashion to correct the sideways shift involved.

Conversely, if a change in strip width is involved, the two cells 62 and 62a furnish a current the sum of which varies, thus triggering operation of motor 66 in the required direction and by an amount sufficient to restore cells 62 and 62a to a condition of half-occultation by the edges of the strip of different width.

It goes without saying that many modifications can be made to the specific embodiments and method hereinbefore described, without departing from the scope of the invention. Thus the two arrangements described precedingly can be combined in the same installation com- 7 prising both the threshold amplifier that enables the influence of the indents to be eliminated and the means for varying the position of the detector that monitors the edge of the strip running past, which detector is mounted on a movable unit for absorbing variations in the width of the strip.

What I claim is:

:1. In an apparatus for guiding an advancing strip between an uncoiling former and a coiling former, by guiding means including at least one oscillating frame supporting at least one orientating roll having an orientation which is responsive to the direction of travel of said strip, an improvement comprising controlling means for the orientation of said orientating roll, at least one primary detector for sensing the transverse position of an edge of said strip without material contact with said edge, a secondary detector associated with a respective frame for sensing the transverse position of an opposite edge of the strip without material contact with such edge, and electrical means connecting said primary detector, said secondary detector and said controlling means, said electrical means collecting displacement information from said primary detectors and damping information from said secondary detector, to damp oscillations of said frame when correction is made due to change in orientation in said strip.

2. In an apparatus as claimed in claim 1, wherein said detectors respectively comprise a light source and a photoelectric cell, each said cell having a sensitive surface half of which is masked, when the strip to be guided occupies the desired position and when said oscillating frame is oriented perpendicularly to the direction of travel of said strip.

3. In an apparatus as claimed in claim 1, wherein said detectors are electrically connected in an electrical bridge comparator, said electrical means comprising amplifier means electrically connected to said comparator, and a motor connected to said amplifier means for actuation of said oscillation frame.

4. In an apparatus according to claim 1, wherein said electrical means is interposed between said primary detector and said controlling means and comprises threshold means above which threshold said electrical means are locked and under which said electrical means are active.

5. In an apparatus as claimed in claim 1: a support movable transversely with respect to the direction of travel of said strip and integrally supporting said primary detector, detecting means for the width of said strip, and means for displacing said support according to variations of width of said strip.

6. In an apparatus as claimed in claim. 5: a third similar detector on said support, a second movable support, guiding means for said first and second supports, a fourth similar detector integral with said second support and disposed in the vicinity of the second opposed edge of said strip, moving means for moving said first and second support in opposite directions, and controlling means for said moving means electrically connected to said third and fourth detectors.

7. In an apparatus as claimed in claim 6, wherein said third and fourth similar detectors comprise photo-electric cells having sensitive surfaces which are half masked by respective edges of said strip in equilibrium positions of said supports, said electrical means comprising electrical connecting means for additionally receiving the information from said cells, an electrical bridge electrically connected to said connecting means, an amplifier electrically connected to said bridge, a second threshold device electrically connected to said amplifier, a polarized change-over relay electrically connected to said second threshold device, and an electric motor electrically connected to said relay and mechanically connected to said moving means of said first and second supports.

8. In an apparatus as claimed in claim 3, wherein said amplifier means comprise a first amplifier electrically connected to said bridge comparator and to said motor, and a second amplifier including a threshold device electrically connected to a relay having a contact open in active position and interposed between said first amplifier and said motor.

9. In an apparatus as claimed in claim 1, wherein said oscillating frame includes a second pinch roll, a pair of jacks mechanically connected to journals for pivots of said pinch roll and to said frame, and pivots for said frame disposed on either side of the passage of said strip between said pinch and orientating roll, perpendicularly to said passage.

References Cited by the Examiner UNITED STATES PATENTS 2,782,030 2/1957 Webster et al. 2262l 2,842,361 7/1958 Miller 22621 3,090,534 5/1963 Fromrner et al 226-21 FOREIGN PATENTS 645,334 1/1950 Great Britain.

ROBERT B. REEVES, Primary Examiner.

HADD S. LANE, Examiner.

Claims (1)

1. IN AN APPARATUS FOR GUIDING AN ADVANCING STRIP BETWEEN AN UNCOILING FORMER AND A COILING FORMER, BY GUIDING MEANS INCLUDING AT LEAST ONE OSCILLATING FRAME SUPPORTING AT LEAST ONE ORIENTING ROLL HAVING AN ORIENTATION WHICH IS RESPONSIVE TO THE DIRECTION OF TRAVEL OF SAID STRIP, AN IMPROVEMENT COMPRISING CONTROLLING MEANS FOR THE ORIENTATION OF SAID ORIENTATING ROLL, AT LEAST ONE PRIMARY DETECTOR FOR SENSING THE TRANSVERSE POSITION OF AN EDGE OF SAID STRIP WITHOUT MATERIAL CONTACT WITH SAID EDGE, A SECONDARY DETECTOR ASSOCIATED WITH A RESPECTIVE FRAME FOR SENSING THE TRANSVERSE POSITION OF AN OPPOSITE EDGE OF THE STRIP WITHOUT MATERIAL CONTACT WITH SUCH EDGE, AND ELECTRICAL MEANS CONNECTING SAID PRIMARY DETECTOR, SAID SECONDARY DETECTOR AND SAID CONTROLLING MEANS, SAID ELECTRICAL MEANS COLLECTING DISPLACEMENT INFORMATION FROM SAID PRIMARY DETECTORS AND DAMPING INFORMATION FROM SAID SECONDARY DETECTOR, TO DAMP OSCILLATIONS OF SAID FRAME WHEN CORRECTION IS MADE DUE TO CHANGE IN ORIENTATION IN SAID STRIP.

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