US 3610546 A
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United States Patent  Inventor Francis J. McGorry 128 Vermillion Drive, Levittown, Pa. 19054 ] Appl. No. 849,816  Filed Aug. 13, I969  Patented Oct. 5, 1971  AUTOMATIC STRIP ALIGNMENT SYSTEM 8 Claims, 3 Drawing Figs.  US. Cl 242/57.l, 226/15, 242/786  Int. Cl B6511 25/26  Field of Search 242/57,
 References Cited UNITED STATES PATENTS 2,641,416 6/1953 McCleary et a1. 242/57.l 2,643,117 6/1953 Frisbie et a]. 242/57.1 2,735,630 2/1956 Ziebolz..... 242/57.l 2,860,841 11/1958 .lacobsen 242/57.l 2,941,572 6/1960 242/57.1 X
Densen et al.
2,990,173 6/1961 Melville 242/57 .l X 3,322,362 5/1967 Nordgren 242/57.l 3,322,963 5/1967 Pages 242/571 X Primary ExaminerStanley N. Gilreath Assistant ExaminerWerner H. Schroeder Attorney-Martin J. Carroll ABSTRACT: In a strip-processing line in which the trailing end of a first strip is welded to the leading end of a second strip vertically spaced from the first strip, apparatus is provided for aligning one edge of the moving first strip with the corresponding edge of the clamped second strip. A carriage movable transversely of the strip carries a pair of edge sensors one in alignment with each strip. When the edges of the strip are out of vertical alignment, an alignment control operable by the sensor associated with the moving strip moves the moving strip transversely until the edges return to alignment. A control is provided to move the carriage into a rearward position away from the strip when the leading edge is not clamped and into a forward operative position when clamped. The carriage position control prevents operation of the alignment control until the leading edge of the second strip is clamped and its sensor is in alignment therewith.
PATENTEU UBT 5197i SHEET 1 BF 2 INVENTOR FRANCIS J. MCG'ORRY m M his Allarnay PATENTED BET 5197! SHEET .2 BF 2 IN VENTOR FRANCIS J. McGORRY a, m awq his Attorney AUTOMATIC STRIP ALIGNMENT SYSTEM This invention relates to an automatic strip alignment system and, more particularly, to a system for aligning the edges of vertically spaced strips. In a continuous processing of strip, particularly steel strip, the common practice is to process one length of strip from a first uncoiler while another coil of strip is positioned in a second uncoiler and its leading end squared off and held stationary at an in-line welding machine until the first coil is depleted. The trailing end of the first coil is then held stationary and welded to the leading end of the second coil. Unless the strips are properly aligned before the weld is made, offset welds will occur which is detrimental for many reasons.
Prior to my invention, the edges of the strip were normally aligned by sight of eye. Since the strips are vertically spaced a distance of several inches, errors of one-quarter inch or more commonly occur in the welds.
lt is, therefore, an object of my invention to provide apparatus for automatically aligning the edges of the strips before the weld is made.
This and other objects will be more apparent after referring to the following specification and attached drawings, in which:
FIG. I is a schematic view of a strip processing line having my invention incorporated therein; and
H65. 2 and 2a when joined on lines A-A to -0 are a schematic diagram of the control system of my invention.
Referring more particularly to the drawings, reference numeral 1 indicates the No. 1 uncoiler from which a coil of strip S is fed. A coil of strip SB is fed from No. 2 uncoiler 2. Hydraulic motors 3 and 4 move the uncoilers l and 2 transversely. Oil is fed to one end of motor 3 from pump 5 through conduit 6 and three-way solenoid valve 7 and to the other end through conduit 8 and three-way solenoid valve 9. The valves 7 and 9 also control return flow of oil to pump 5 through conduits l0 and 11, respectively. When solenoid 7S is energized, valve 7 will connect motor 3 to conduit 6 and when deenergized to conduit 10. When solenoid 9S is energized valve 9 will connect motor 3 to conduit 8 and when deenergized to conduit 11. Oil is fed to one end of motor 4 from pump 5 through conduit 12 and three-way solenoid valve 13 and to the other end through conduit 14 and three-way solenoid valve 15. The valves 13 and 15 also control return flow of oil to pump 5 through conduits l6 and 17, respectively. When solenoid 135 is energized valve 13 will connect motor 4 to conduit 12 and when deenergized to conduit 16. When solenoid 15S is energized valve 15 will connect motor 4 to conduit 14 and when deenergized to conduit 17. The strip passes over idler rolls 18 to a welding machine 19 and then around pinch rolls 20 through a looping pit 21 to a strip-processing line 22 such as an electrolytic tinning line. The parts so far described, except for the solenoid valves, are conventional. v
According to my invention 1 provide an edge sensor assembly 24 between the rolls l8 and welding machine 19. The assembly 24 includes a frame 26 having vertically spaced traversing rods 28 extending transversely of the direction of travel of the strip. A traversing carriage 30 is supported on the rods 28 by means of rolls 32. A pair of edge sensors 34 and 34B is provided in vertical alignment on the carriage 30 in line with the top and bottom strips. These are preferably Lenco Model 163 manufactured by Columbia Research Company. This is a radio frequency wave sensor having an area in its jaws where a signal change occurs when metal is present. A traversing rack 36 attached to the carriage 30 is driven from a motor 38 through a gear reducer 40 and pinion 42. Power for driving motor 38 is provided from power source L1, L2 through silicon controlled rectifiers 44 or 46 connected in parallel. The direction of rotation of motor 38 is controlled by means of driver 48 connected to rectifier 44 and driver 50 connected to rectifier 46. The drivers 48 and 50 supply the proper amount of current to turn on and off rectifiers 44 and 46 and may be Engineered Electronics Company Model No. T-l34. Normally open limit switches 52 and 54 are located adjacent the path of travel of rack 36. The switch 52 limits forward travel of the carriage 30 when it is opened by bracket 52B and switch 54 limits reverse travel of the carriage 30 when opened by the carriage. Switches 52 and 54 are connected in parallel to a 24 V. direct current power source L3, L4 which is common to all relays. Switches 52 and 54 are connected in series with relay coils 56 and 58, respectively. Relay coil 56 has a normally closed contact 56C in series with rectifier 46 and a normally open contact 56Cl, which when closed operates a safety limit relay to retract the carriage 30 out of the line. Relay coil 58 has a normally closed contact 58C in series with rectifier 44.
The output of sensor 34 is connected through a voltage divider 60 to the plus input of an operational amplifier 62 and the output of sensor 34B through voltage divider 64 to the plus input of an operational amplifier 66. Adjustable power sources 68 and 70 supply reference voltage to the minus input of amplifiers 62 and 66, respectively. The outputs of amplifiers 62 and 66 are fed to position indicators 72 and 74, respectively, also to a motor control signal conditioning control circuit 76 through a normally closed contact 78C or a normally open contact 78Cl operated by relay coil 78, and also to an uncoiler control signal conditioning circuit 80 through a normally open contact 82C or a normally closed contact 82C1 operated by relay coil 82. Circuit 76 includes sensitivity rheostats 83 which determine the value of the error signal from amplifiers 62 and 66 which will activate the circuit 76. Relay coils 78 and 82 are connected in parallel with each other and in series with normally open contact 84C operated by relay coil 84. Contact 86 of a selector switch is connected in series with coil 84. When the top strip S is stationary and the bottom strip SB running the operator sets the switch so contacts 86 are open. Thus, the output of amplifier 62 is fed to circuit 76 and that of amplifier 66 to circuit 80. When the top strip is running and the bottom strip stationary the contacts 86 are closed. Thus, the output of amplifier 62 is fed to circuit 80 and that of amplifier 66 to circuit 76. Relay 84 also has normally open contacts 84C1 and 84C2 and normally closed contacts 84C3 and 84C4.
Control circuit 76 includes a transistor 88 which controls a transistor 90, the output of which is connected to a voltage comparator 92 which is connected to driver 50. The circuit 76 also includes a transistor 94 which controls a transistor 96, the output of which is connected to driver 48.
Control 80 is similar to control 76 and includes a transistor 98 which controls a transistor 100, the output of which is connected to a voltage comparator 102. Control 80 also includes a transistor 104 which controls a transistor 106 and also sensitivity rheostats 107 similar to rheostats 83. The comparator 102 is connected to an inverter 108, the output of which is connected to an AND gate 110. Signals from drivers 48 and 50 are also fed to gate 110. The only time gate 1 10 can be enabled is when motor 38 is not running and when running strip SB has moved forward causing its edge to move away from the center point of the signal change area of its sensor. The output of gate 110 is fed to an AND gate 112 and an OR gate 114. Time controlled pulses of a one shot multivibrator 116 is also fed to gate 112 to do the correcting. The pulses originate from a free running multivibrator 118 whose frequency is determined by capacitors 120 and 122 and which is connected to multivibrator 116 through capacitor 124. When gate 110 has a zero output, gate 112 becomes enabled for every correction pulse that appears at its input. Each time gate 112 is enabled it turns on driver 126 which is connected to and picks up relay coils 128 and 130 depending which coil has voltage applied to it through 84Cl or 84C3 which are connected in parallel with each other in series with normally closed contact 132C of uncoiler and oil pump safety relay 132. Solenoid coil 78 is energized through normally open to 128C to control the position of uncoiler 1 and solenoid coil 13S is energized through normally open contact 130C to control the position of uncoiler 2.
The output of transistor 106 is connected to AND gate 138 which is also fed from drivers 48 and 50. The output of gate 138 is fed to AND gate 140 and also to gate 114. The output of multivibrator 116 is also fed to gate 140. Gate 138 is only enabled when motor 38 is not running and strip SB is running and has made a reverse movement error. gate 140 turns driver 142 on and off at the pulsed rate. Driver 142 will pick up relay coil 144 closing its contact 144C and complete a circuit to solenoid coil 158, thus positioning uncoiler 2 and the strip SB in the correct position. With the strip S being fed from uncoiler 1, the driver 142 will pick up relay coil 148 closing its contact 148C and complete a circuit to solenoid coil 9S, thus positioning uncoiler l and the strip S in the correct position. Voltage is applied to coils 144 and 148 through contacts 84C4 and 84C2, respectively, which are connected in parallel with each other and in series with contact 132C.
When an error in the position of the running strip occurs the OR gate 114 is enabled and its output is inverted in inverter 152 and fed to driver 154 which enables relay coil 156 through contact 132C closing its contact 156C to complete a circuit to relay coil 158 closing its normally open contact 158C. This completes a circuit to pump motor 159 from power source L1, L2 causing the pump to run.
A relay coil 160 having a normally closed contact 160C is connected to DC power lines L3, L4 through contacts 162 and 164 which are closed when the mill is running. Also connected to DC power lines L3, L4 through a pushbutton switch 166 is a relay coil 168 having a normally open contact 168C and a normally closed contact 168C1. Contact 160C is connected to power source L3, L4 in series with coil 132. Thus, its normally closed contact 132C will be open when the mill is not running and prevent movement of the coilers 1 and 2 and operation of pump 5. Relay coil 170 is also connected in series with contact 160C. As long as the line is not running its contacts 170C and 170C! are open. Since contact 170C is in the line from power source 68 and contact 170C1 in the line from power source 70, the outputs of amplifiers 62 and 66 will be such as to cause the motor 38 to turn in the direction which will move the sensors 34 and 348 out of the line. When the line is operating the reference voltage is applied to the amplifiers 62 and 66 and the motor 38 will operate to move the sensors into the line until they are correctly positioned.
A safety limit relay coil 172 is connected to power source L3, L4 through brass strips 174 and 1748 connected in parallel and attached to the jaws of the sensors 34 and 348. Contact 56C1 is also connected in parallel with brass strips 174 and 1748. The same side of coil 1172 is connected to a normally closed reset switch 176 and normally open contact 172C. Relay coil 172 also operates a normally open contact 172C1 connected in the circuit to coil 170. When contact 56C1 or the edge of either strip 174 or 174B contacts the top or bottom strip it picks up coil 172 and locks itself in through contact 172C. Closing of contact 172Cl causes relay 170 to pick up and move the sensors out of the line. Relay 172 will remain picked up until safety switch 176 is opened. When this is done relay 170 drops out and the sensors now return into the line.
When switch"l66 is momentarily closed it causes relay coil 168 to pick up and lock it in through its contact 168C and a normally closed pushbutton switch 178. Thus, relay coil 168 remains energized until switch 178 is opened. Normally closed contact 168C1 is connected in parallel with contact 160C so as to keep relays 132 and 170 picked up and the sensors out of the operating line when relay coil 168 is not picked up.
The operation of my control is as follows:
To calibrate the system, two pieces of metal are inserted into the jaws of sensors 34 and 34B with their edges in vertical alignment. When they reach the centers of the signal change area of the sensors a DC voltage appears at the output of each sensor. With the installed circuit this voltage will be approximately 17.5 volts. The voltages appear at voltage dividers 60 and 64 and a portion thereof are fed to amplifiers 62 and 66. Also fed into amplifiers 62 and 66 are the reference voltages from adjustable voltage sources 68 and 70 and these reference voltages are adjusted until the output of each amplifier is zero as indicated on meters 72 and 74.
The line can now be started with a coil of strip SB in the uncoiler 2. With the mill running, contacts 162 and 164 will be closed. Contact 86 will be open so that relay contacts 84C3 and 84C4 are closed and 84C, 84C] and 84C2 are open. At this time switch 166 is kept open so that my control will not be in operation. A coil of strip S is then put on uncoiler 1 and the front end fed into the welding machine 19 and clamped in centered position with its edge becoming the control point. Switch 166 is then momentarily closed to lock a coil 168 and close contact 132C. Once the strip S is locked in position, the carriage 30 which has been in retracted position will be moved forward due to the unbalance in carriage position amplifier 62 which will cause motor 38 to rotate in the direction to move the carriage 30 forward until the strip S reaches the center point of the signal change area of the edge sensor 34. This portion of the control then will be inoperative unless the stationary strip S moves out of the center point of the signal change area.
The uncoiler control now comes into operation. As long as the edge of the strip SB remains in alignment with the edge of strip S nothing happens. If the strip SB moves forward into the line an unbalance occurs in amplifier 66 and a signal passes to uncoiler position control 80, which causes a signal to be applied to voltage comparator 102. Then, as previously described, relay coil 144 is energized to energize solenoid 15S and relay coil 156 is energized to start up the pump. Energization of solenoid 158 will cause valve 15 to open to conduit 14 and cause coiler 2 to move rearward until the edges of strip S and SB are aligned. If the strip SB moves rearward out of line with strip S, a signal of opposite polarity will occur at amplifier 66 so that the signal from control will be applied to the AND gate 138. This, as described above, energizes relay coils 148 and 156. Energization of coil 148 completes the circuit to solenoid 138 which will cause valve 13 to open to conduit 12 and thus move coiler 2 forward until the edges of strips S and SB are aligned.
When strip SB is terminated its end will be welded to the forward end of strip S in the usual manner. However, just prior to this time, switch 164 is opened to retract the carriage 30 out of the line. After welding, contact 164 is closed and uncoiling of strip S starts. Another coil of strip SB is then put on uncoiler 2 and the front end fed into the welder 19 and clamped in centered position with its edge now becoming the control point. Switch 166 is then depressed to energize and lock in coil 168 and switch 86 is closed to energize coil 84. This closes contacts 84C, 84C1 and 84C2 and opens contacts 84C3 and 84C4. Closing of contact 84C energizes coils 78 and 82, thus connecting amplifier 62 to control 80 and amplifier 66 to control 76. 1f the strip S moves transversely forward an unbalance occurs in amplifier 62 and a signal passes to control 80 which causes a signal to be applied to voltage comparator 102. Then, as described above, relay coil 148 is energized to energize solenoid 9S, thus causing uncoiler 1 to move rearward until the edges of strips S and SB are aligned and relay coil 156 is energized to start pump 5. 1f the strip S moves rearward out of alignment a signal of opposite polarity will occur at amplifier 62 so that signal from control 80 will be applied to the AND gate 138. This, as described above, energizes relay coils 128 and 156. Energization of coil 128 completes the circuit to solenoid 7S which will cause valve 7 to open to conduit 6 and thus move coiler 1 forward until the edges of strips S and SB are aligned.
When strip S is terminated the strips are welded end to end in the usual manner after switch 164 is opened. The operation is then repeated with a new coil of strip S being provided.
While one embodiment of my invention has been shown and described, other adaptations and modifications may be made.
1. Apparatus for aligning corresponding edges of lengths of strips preparatory to fastening the strips end to end which comprises a pair of uncoilers for mounting the lengths of strip in coiled form, a strip connector located longitudinally from said uncoilers, means for moving said strips from said uncoilers in the direction of said strip connector with one strip spaced vertically above the other strip, means for separately moving each of said uncoilers transversely, means for selectively clamping the ends of said strips from movement, an edge sensor associated with each of the top and bottom strips located between said uncoilers and strip connector, an alignment control connected to each of said sensors, and means operable when one of said strips is clamped and the other of said strips is moving longitudinally to cause the alignment control associated with the moving strip to move that strip and its uncoiler transversely until its edge becomes aligned with the corresponding edge of the clamped strip, said top and bottom strips being alternately moving and aligned with clamped bottom and top strips, respectively.
2. Apparatus according to claim 1 including a first amplifier connected to said top sensor, a second amplifier connected to said bottom sensor, and means for connecting said first amplifier to said alignment control when the bottom strip is clamped and connecting said second amplifier to said alignment control when the top strip is clamped.
3. Apparatus according to claim 1 including a transversely movable carriage, means mounting said edge sensors on said carriage in vertical alignment one associated with the top strip and the other associated with the bottom strip, means for moving said carriage into a forward position in which said sensors are adjacent one edge of the lengths of strip and to a rearward position away from said strip, a carriage position control for operating said carriage-moving means when the leading end of a strip is clamped in position, means connecting the sensor of said clamped strip to said carriage position control, and means operable by said carriage position control when he edge of said clamped strip is out of line with its sensor to cause said carriage moving means to move said carriage in the proper direction to being said edge and associated sensor into alignment.
4. Apparatus according to claim 3 including means operable by said carriage position control to prevent operation of said alignment control except when said clamped strip edge is in alignment with its sensor.
5. Apparatus according to claim 4 including a first amplifier connected to said top sensor, a second amplifier connected to bottom of sensor, and means for connecting said first amplifier to said carriage position control and said second amplifier to said alignment control when the top strip is clamped and connecting said first amplifier to said alignment control and said second amplifier to said carriage control when the bottom strip is clamped.
6. Apparatus according to claim 5 in which the means for moving each uncoiler transversely is a fluid motor, and in which the first and second amplifiers are operational amplifiers.
7. Apparatus according to claim 6 including a pump for supplying fluid to said fluid motors, and means operable by said alignment control for starting said pump in operation when said moving strip is out of alignment with said clamped strip.
8. Apparatus according to claim 3 including a first amplifier connected to said top sensor, a second amplifier connected to said bottom sensor, and means for connecting said first amplifier to said carriage position control and said second amplifier to said alignment control when he top strip is clamped and connecting said first amplifier to said alignment control and said amplifier to said carriage control when the bottom strip is clamped.