US3094295A

US3094295A - Apparatus for open coiling of strip material

Info

Publication number: US3094295A
Application number: US109729A
Authority: US
Inventors: Frederick W A Ward
Original assignee: Steel Company of Canada Ltd
Current assignee: Steel Company of Canada Ltd
Priority date: 1961-05-12
Filing date: 1961-05-12
Publication date: 1963-06-18
Anticipated expiration: 1980-06-18
Also published as: BE614769A; GB941350A; DE1449685A1

Description

F. w. A. WARD 3,094,295 APPARATUS FOR OPEN COILING OF STRIP MATERIAL Filed May 12, 19e1 June 18, 1963 3 Sheets-Sheet 1 V V- v a x if;

. F INVENTOR.

fiwonwcx MM. WARD BY M W W ATTORNEYS.

June 18, 1963 F. W. A. WARD APPARATUS FOR OPEN COILING 0F STRIP MATERIAL Filed May 12, 1961 3 Sheets-Sheet 2 r32 /3! /33 rrn n11 i W I 1 null INVENTOR. fiemEe/c/a 14/ A. 1/1/4220 BYM W 9 /M ATTORNEYS.

June 18, 1963 F. w. A. WARD v 3, ,2

APPARATUS FOR OPEN COILING OF STRIP MATERIAL- Filed May 12.1961

' 3 Sheets-Sheet 3 I IIIIIII F" INVENTOR.

Z sewn/m w. A. W/Wfi ATTORW United States harem O 3,094,295 APPARATUS FOR OPEN COILING OF STRIP MATERIAL Frederick W. A. Ward, Hamilton, Ontario, Canada, as-

signor to The Steel Company of Canada, Limited, Hamilton, Ontario, Canada, a corporation of Canada Filed May 12, 1961, Ser. No. 109,729 17 Claims. (Cl. 242-612) This invention relates to apparatus for recoiling tight Wound coils of strip metal into loose or open coils having the laps thereof spaced apart, and more particularly to apparatus for forming such open coils of strip metal without the use of spacer strands or the like.

A recent development in the treatment of strip steel or the like is the so-called open coil process wherein a tight wound coil of strip is recoiled into open form with spaces between the laps of the coil whereby atmosphere Which heats, and/ or modifies the composition of, the strip may be circulated through the coil in contact with both sides of the coil throughout its entire length, thus effecting most economical, rapid and uniform processing of long lengths of strip metal.

In one form of the open coil process a tight coil of strip metal is rewound with a spacer strand, which may be in the form of a string, corrugated metal strip or the like, in between the laps. The thickness of the spacer strand is such that the desired lap spacing is established. In the case of a spacer string the string is removed before treatment of the coil thus leaving the spaces completely unobstructed but, when a corrugated metal spacer or the like is used, it may be left in position during treatment.

Although the use of a spacer strand is effective and desirable in many instances, there are certain applications of the open coil process wherein it is advantageous to form the open coil directly from the tight coil without the use of any spacer means whatever. Accordingly it is an object of the present invention to provide an improved apparatus for forming open coils from tight coils of strip metal which Will rewind a tight coil into open form with a uniform predetermined gap between each lap of the opened coil without the use of any spacer string or the like.

Other objects of my invention include the provision of a stringless coil opening apparatus which may readily be regulated to form a predetermined and desired space or gap between each of the laps of the open coil or which may be so set as to give varying lap spacing at successive portions of the open coil; and the provision of coil opening apparatus wherein the speed of the open coil turntable is automatically correlated with the speed of the strip being fed thereto whereby the predetermined spacing will be maintained between the laps of the open coil throughout the entire recoiling operation.

:The above and other objects of my invention will appear from the following description of one embodiment thereof, reference being had to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic perspective view illustrating the principal elements of my improved coil opening apparatus; and

FIGURE 2 is an enlarged vertical cross sectional view of the ball and disc integrator type variable speed unit shown in FIGURE 1;

FIGURE 3 is a View generally similar to FIG. 1, but omitting the tight coil turntable and strip guides and illustrating a modified strip feeding and coiling apparatus; and

:FIGURE 4 is a diagrammatic illustration of an electrical control system embodying my invention.

A tight Wound coil C, having its laps in close engagement with each other, is supported on the tight coil Patented June 18, 1963 turntable T which in turn is driven by a shaft 1 which extends into the base 2 in which a suitable variable speed drive motor is provided for rotating the turntable T. A suitable mandrel M or the like extends up into the center opening in the coil C to maintain same in proper centered position on turntable T during unwinding. The strip S as it is unwound from the coil C passes through a tension control unit of any suitable type diagrammatically indicated at 3 on the drawing and which is adapted to control the rotation of turntable T so that a substantially uniform tension is maintained in the strip between the coil C and the bridle rolls 4 and 5.

In order to maintain the strip S in proper vertical position as it approaches the loose coil turntable T, I provide an adjustable bottom strip edge guide unit G which includes a plurality of rolls 6 carrying a belt 7 which extends horizontally and on which the lower edge of strip S rests. This edge guide unit G is vertically adjustable by means of a screw 8 which supports the roll carrying block 9 at its upper end and has a non threaded bearing support in a stationary block 10 on the frame of the machine. As will be more fully explained later, the vertical position of the belt 7 is so adjusted that the bottom edge of the strip S as it leaves the driven bridle roll 5 Will be at an elevation slightly above the top face of the open coil turntable T. Vertical guide rolls 11 and 12 maintain the strip in proper position to pass over the edge guide 7 and an adjustable upper edge guide unit G, similar in its essential parts to the edge guide G, is adapted to engage the upper edge of the strip S and prevent vertical movement thereof. It will be understood that this upper edge guide unit G may be adjusted vertically to accommodate different widths of strip.

In order to feed the strip S to the open coil turntable T I provide a pair of bridle rolls 4 and 5 around which the strip passes. The first bridle roll 4 is not driven and rotates with the strip as it moves thereover. Its function is to maintain the necessary circumferential contact of the strip with the surface of the second bridle roll 5 which is driven through shaft 13, gear box 14 and motor 15. In the preferred operation of my apparatus the roll 5 is driven at a constant speed and accordingly the strip S will be advanced toward the turntable T in the direction of the arrow at a constant lineal velocity. In order further to insure proper contact of the strip with the driven bridle roll 5, a snubber roll 16 is adapted to coact with roll 5. This snubber roll also assists in guiding the strip S in proper direction toward the loose coil turntable T and is driven through shaft 17 and gear box 18 by a motor 19. The speed of roll 16 is correlated with that of roll 5 to feed the strip S at the desired lineal velocity.

The open coil turntable T, on which the open coil C is formed and supported, is driven by a vertical shaft 20 which in turn is connected to the variable speed electric motor 21 through the angle gear box 22. It will be understood that in the apparatus of FIGURE 1, as the strip S is fed to the turntable T at a constant velocity, the speed of rotation of the turntable T will have to be progressively reduced as the diameter of the open coil C builds up. Furthermore this progressive re duction in the rate of rotation of the turntable T during the formation of an open coil of strip steel must be very accurately controlled as will be understood from the fact that the steel strip material for which my invention is particularly adapted may have a thickness or gage !of from about .010 up to about .08" or greater, while the space between the adjacent surfaces of adjacent laps of the completed open coil will ordinarily vary from about /2 to about 3 times the strip thickness. As the finished open coil may be as much as 10' in outside diameter,

ice

great accuracy of control of the strip speed and the open coil turntable rotation is necessary to maintain the relatively very small lap spacing in such a large diameter open coil. As will be more fully explained later, in some cases the lineal velocity of the strip f-eed may be varied and the speed of rotation of the turntable T held constant.

To effect the desired control of the rotation of turntable T I provide a variable speed unit generally indicated at F. As illustrated this unit is .of the type known as a ball and disc integrator but it will be understood that other equivalent devices may be employed. The unit F, as is best seen in FIGURE 2, includes a driving element in the form of a constant speed drum 23 mounted on a shaft 24 which is rotatably supported in

bearings

25 and 26. The shaft 24 extends to angle gear box 27 which establishes driving connection between shaft 24 and shaft 28 which in turn is connected to, and driven by, the driven bridle roll 5. Thus the speed of rotation of the driving element 23 of the ball and disc integrator F is constant and is directly proportional to the speed of rotation of the bridle roll and thus to the speed of travel of the strip S. A driven element in the form of a disc 29 is enclosed within the housing 30 of the .unit F and has an upwardly extending cylindrical portion 31 which is supported in bearings 32 and 33 in housing 30. The shaft 34 extends from portion 31 through the top of housing 30 and is driven by and rotates with the disc 29.

The variable speed unit F also has an adjustable or variable means for effecting driving connection between the driving element 23 and the driven element 29 and varying the speed of the driven element 29 relative to that of the driving element 23. This means includes the shaft 35 which extends generally parallel to drum 23 and has a bearing 36 in housing 30. The inner end of shaft 35 is threaded to form a feed screw 37 which has threaded engagement with a movable traverse block member 38. This block 38 is supported between the drum 23 and the disc 29 and has a cylindrical hole 39 extending vertically therethrough in which are disposed a pair of superimposed steel balls 40 and 41. These balls are of a diameter to have a close rotational fit in the hole 39 and, when held therein, extend between the drum 23 and the disc 29 and effect a driving connection therebetween. Thus when the drum 23 is rotated it will frictionally engage and rotate the ball 40 about a horizontal axis. The ball 40 in turn engages the ball 41 and will rotate it about a horizontal axis. As the upper portion of the top ball 41 has frictional engagement with the under face of the disc 29, rotation of the ball 41 will cause corresponding rotation of the disc 39 and the shaft 34. The speed of rotation of the disc 29 relative to the speed of rotation of the drum 23 will depend on the radial disposition of the balls 40 and 41 relative to the center of the disc 29.

When the parts are in the position seen in FIGURE 2 and the drum 23 is rotated at a constant speed due to its driving connection with the constant speed bridle roll 5, the disc 29 will be driven at a certain definite speed depending on the radial position of the balls 40 and 41. Now if the shaft 35 and feed screw 37 are rotated to cause the movable block 38 to move to the left as seen in the drawings, the length of the radius at which the ball 41 engages the disc 29 will become greater and, as the rate of rotation of the ball 41 remains constant but the effective circumference on which the ball 41 engages the disc 29 said disc becomes greater, the rate of rotation of the disc 29 will be progressively decreased.

With this explanation of the mode of operation of the variable speed unit F, and as previously noted this unit may take other forms than the ball and disc integrator device illustrated, it will now be explained how the desired speed control of the turntable T is effected.

The variable speed turntable drive motor 21 is connected at its left hand end (FIG. 1) to drive the turntable T. A shaft 42 extends from the right hand end of motor 21 and is connected to shaft 43 through an angle gear box 44. The adjustable variable speed control unit 45, preferably having a wide range of speed variation, is disposed between shaft 43 and shaft 46. By adjusting the regulator handwheel 45 of unit 45 the speed of shaft 46 may be varied relative to the speed of shaft 43 over a considerable range. Angle gear box 47 establishes driving connection between shaft 46 and shaft 48 which is connected through a speed reducer 49 and clutch 35 to shaft 35 of the variable speed unit F These driving connections between the motor 21 and the unit F are adapted to actuate the

adjustable means

38, 40, 41 of unit F to cause same to traverse the disc 29 and thus effect progressive variations in the speed of driven element 29.

From the preceding description it will be observed that the traverse block 38 of variable speed unit F and the balls 40 and 41 (which constitute an adjustable means for varying the speed of driven element 29 relative to that of driving element 23) will be moved radially of the disc 29 .by the feed screw 37 at a rate of travel which will vary directly with variations in the rate of rotation of the open coil turntable drive motor 21. The actual rate of movement of the block 38 and the balls 40 and 41 across the face of disc 39 for any given speed of rotation of motor 21 may be varied by adjusting the speed control unit 45 through its regulator 45 and, as will be explained more fuly later, this speed control unit 45 comprises means for adjustably varying the rate at which the ratio between the speed of rotation of the turntable and the speed of feed of the strip is changed. This enables my apparatus to be set to form an open coil having any desired spacing of the laps and to accommodate coils of different strip thickness.

The vertical shaft 34 which rotates with the driven disc 29 is connected through a gear box 50 to a shaft 51 which in turn drives a tachometer type generator unit 52. This unit 52 is adapted to generate an electrical current which varies in accordance with the speed at which it is driven. The electrical output of unit 52 is conducted through wires 53 to the control unit 54- to which electrical supply lines 55 are connected from any suitable source of current and from which the wires 56 extend to the variable speed turntable drive motor 21. The function of the control box 54 is to vary the current supplied to motor 21 in accordance with variations in the control current from the generator unit 52 in such a manner that, as the disc 29 and generator 52 slow down, the motor 21 will correspondingly slow down. The specific type of electrical control apparatus employed in unit 54 to effect this result forms no part of the present invention and any suitable control means, responsive to the speed of the driven element of the variable speed unit F for varying the speed of rotation of the open coil turntable drive motor 21, could be employed.

The forming of an open coil from a tight coil by my above described apparatus will now be explained. Before the start of a coil opening operation the variable speed unit F must be set at its start position with the balls 40 and 41 at their innermost position relative to the disc 29. This may be effected by disengaging the clutch 35 between shaft 35 and speed reducer 49 and turning shaft 35, by any suitable means (not shown) sothat the screw 37 moves the block 38 inwardly (to the right as seen in FIGS. 1 and 2) until the established starting position is reached. For purposes of this explanation this may be considered to be the position seen in FIGURE 2 of the drawings. Clutch 35 is then reengaged and the strip S from the tight wound coil C is led through between the edge guides G and G and around the bridle rolls 4 and 5 and its forward end secured to a mandrel M or other anchoring device on the turntable T. The diameter of mandrel M is, of course, equal to the desired inside diameter of the open coil that is wound therearound. The

, variable speed control unit 45 is set by adjusting the regulator 45' to give the desired and pro-determined ratio between the speed of the motor 21 and the speed of shaft 4'6. The speed of rotation of shaft 46 determines the speed of rotation of shaft 35 and screw 37, and accordingly determines the rate of traverse of the block 33 and the balls 40 and 41 across the face of disc 29 relative to the speed of rotation of motor 21. When the motor 21 rotates to drive the turntable T in coil forming direction as indicated by the arrow in FIGURE 1, the direction of rotation of shaft 35 is such that the block 38 will be traversed to the left from the start position seen in FIGURES 1 and 2.

When the strip has been fed through the bridle rolls and secured to the mandrel M on the open coil turntable T the motors driving the bridle roll 5, turntable T, and turntable T are simultaneously started. When this occurs the strip S is fed through the bridle rolls at a constant velocity toward the turntable T. The control of motor 21 by unit 54 is such that, when the apparatus is started, the peripheral speed of a point on the outer face of the mandrel M is approximately the same as the lineal velocity of the strip S as it leaves the bridle roll 5. With constant strip speed, in order to form an open coil having uniform lap spacing, it is necessary smoothly and progressively to reduce the speed of rotation of the turntable T so that the strip will continuously be fed to the turntable T at a lineal velocity corresponding to the peripheral velocity of a predetermined point on the turntable T. The rate of change of the rotational speed of turntable T is determined from the gage of the strip being coiled and the width of the gap that it is desired to form between the laps of the open coil. The gap between l-aps is determined by the rate at which the balls 40 and 41 are traversed radially of the disc 29, the greater this rate of traverse the greater this gap or space.

When the bridle roll 5 is started, the drum 23 of the variable speed unit F rotates at a speed which is proportional to the lineal speed of the strip toward the turntable T. The starting of the bridle roll motor 15 also signals the motor 21 to start. The screw 37 will start to rotate in the unit F and the block 38 and balls 40 and 41 will start to travel to the left. Thus, as the drum 23 rotates at a constant speed, the speed of rotation of the disc 29 will be progressively reduced. This results in a corresponding reduction in the electrical output of the tachometer generator 52 which in turn, through the control box 54, results in a progressive reduction in the speed of rotation of motor 21 and the turntable T.

It should be noted that, as the speed of rotation of the motor 21 continuously diminishes from the start of the coiling operation to the end, the speed of rotation of the shaft 35 and screw 37 of the variable speed unit F will also continuously diminish proportionately. Thus the rate of traverse of the block 38 and the balls 40 and 41 across the disc 29 is not constant but rather is of a progressively diminishing nature. The result of this is to so control the speed of motor 21 through unit 54 that the gap or spacing between successive laps of the open coil that is formed on the turntable T is uniform. This is important in the forming of open coils of strip metal for the purposes intended because, if the screw 35 were rotated at a constant speed, with resultant constant traverse of the block 38 and the balls 40 and 41 across the disc 29, the result would be a progressively increasing lap spacing from the center of the open coil outwardly.

This would be undesirable because it would make the finished coil larger than necessary for a given length of strip and could result in uneven heat treatment of the material.

From the above explanation it will be understood that the adjustable speed control unit 45, which enables the ratio between the speed of rotation of the turntable drive motor 21 and the variable speed unit traverse shaft 35 to be varied through a substantially infinite number of in- 6 crements and over a relatively large range, enables the rotation of the open coil turntable T to be so controlled that any gage or thickness of strip, Within the design limits of the apparatus, may be recoiled into open coil form with any lap spacing within the designed range of the apparatus. It will be further understood that the unit 45 is preferably provided with indicating means, not shown, whereby the proper adjustment may be visually set, the setting for any given gage and lap spacing being based upon calculations and arranged in tabulated form according to strip gage or thickness and desired lap spacing for convenience in operating the apparatus. By precalcuating the lengths of strip in the tight coils it is also possible to set the variable speed control unit 45 to produce open coils all with the same outside diameter, regardless cf the diameter of the original tight coil. This is advantageous when the open coils are heated in a furnace.

In the apparatus just described, although the lineal speed of the strip S as it approaches the turntable T is intended to be maintained constant, any minor variations in the speed of strip travel will automatically be taken care of because the speed of rotation of the drum 23 of variable speed unit F will vary correspondingly. Thus, if the strip should slow down for some reason the drum 23 would also slow down and the disc 29 would slow down correspondingly. This would reduce the output of the tachometer generator 52 and the energizing current of motor 21 would be correspondingly reduced by control unit 54 with resulting reduction in the speed of rotation in turntable T. If the speed of travel of the strip to the turntable T is held substantially constant the shaft 24 of the variable speed unit F might be driven by an independent constant speed driving means but I prefer to correlate the speed of rotation of the constant speed member of the unit F with the speed of rotation of the driven strip feed roll 5. Although the correlating means is illustrated as a mechanical connection it will be understood that it could readily be electrical in nature.

As previously noted, the bottom edge guide unit G determines the vertical position of the bottom edge of the strip S as it enters, and also as it leaves, the bridle rolls 4 and 5. In order to avoid undesirable scraping of the bottom edge of the strip S on the outer portion and the upper face of the turntable T during forming of an open coil thereon, the bottom edge guide G is preferably so adjusted that the bottom edge of strip S will be disposed a short distance above the top surface of the outer periphery of the turntable T as it moves past this point during a coiling operation. In practice a setting of guide G which establishes this distance at about one-half inch has been found satisfactory in forming open coils up to 8 to 10' feet in outside diameter. This clearance prevents undesired rubbing contact of the strip on the turntable but permits proper location of each lap relative to the previously wound lap. Variations in the Width and gage of the strip being coiled may require variations in this distance for best results and this is provided by the vertical adjustment of units G and G.

In some cases it may be desirable to form open coils having alternate portions of engaging laps and spaced apart laps. Thus a coil might be for-med with three laps in engagement followed by six spaced apart laps, then three more laps in engagement, etc. This type of coil is particularly advantageous in the annealing of light gage strip material where such a coil formation enables the outside diameter of the open coil to be reduced, or the length of strip in a coil of given outside diameter increased, While still providing sufiicient heat transfer surface to effect the desired results. Such a coil may readily be :formed with my apparatus by varying the adjustment of the speed control of unit 45 as the rewound coil is being built up. Thus, for the coil of the example given, the setting of the unit 45 Would be maintained at a value to give engaging laps for the time required to form three revolutions of the turntable T.

The setting of the unit 45 would then be shifted to give the desired lap spacing and maintained at this setting for the time required for six more laps to be laid down. The setting would then again be returned to the first value for another three laps, and this cycle repeated until the complete coil is formed. Such cycling of the unit 45 might be effected by manual manipulation by the regulator 45' or by suitable automatic means.

The apparatus illustrated in FIGURE 1 is arranged for, and adapted to operate by, feeding the strip at a constant rate toward the open coil turntable and varying the speed of the turntable to effect the desired spaced apart lay-up of the laps of the open coil on the turntable surface. As has previously been noted, the same result may be obtained by rotating the turntable at a substantially constant speed of rotation and varying the speed of feed (lineal velocity) of the strip to the turntable. in such an operation the speed of feed of the strip will be progressively increased as the diameter of the open coil builds up on the turntable with resulting progressive change in the ratio between the speed of feed of the strip and the speed of rotation of the turntable.

The apparatus illustrated in FIGURE 3 of the drawings is designed for such an operation. In this view similar parts are identified by the same reference characters as were employed on FIGURE 1. The open coil turntable T in FIGURE 3 is driven at a constant speed of rotation by the motor 21. The speed of drive motor 15 for the driven bridle roll 5 is progressively increased during an open coil forming operation so that the speed of feed of the strip S will be progressively increased as the coil is formed on the turntable T.

In order progressively to increase the speed of strip feed motor 15 a variable speed unit F similar to that shown in FIGURES 1 and 2, is provided. However, in the arrangement of FIGURE 3 the disc 29 constitutes the driving element and is rotated at a constant speed through shaft 60, angle gear box 61, shaft 62, angle gear box 63, and shaft 64 which is driven from constant speed motor 21 through gear box 22. The drum 23 of unit F is the driven member and the driving connection between disc 29 and drum Z3 is effected through a pair of balls carried by the traverse block member 38 which has threaded engagement with the feed screw on the end of shaft 35 as best seen in FIGURE 2.

Rotation of the feed screw shaft 35 is effected from the motor 21 through the shafts 43, variable speed control unit 45, shaft 46, gear box 47, shaft 48, reduction gear 49 and clutch 35'. The driven drum member 23 of the variable speed unit F is supported by and rotates shaft 65 which in turn drives a tachometer generator '66. The signal from this tachometer generator 66 is conducted through Wires 67 to the control unit 68 to which the main supply line 69 is connected. Wires 70 extend from control unit 68 to the strip feed drive motor 15. Furthermore, the drive motor 19 of the snubber roll '16 is connected by wires 71 to the line 70 so that the speed of rotation of the snubber roll 16 will be varied in the same manner as the speed of rotation of the bridle roll 5.

In the operation of the apparatus just described, before starting to form an open coil on the turntable T the clutch 35 will be disengaged and the traverse block 38 of the variable speed unit F will be run to the right to its starting position as has been previously explained in describing the apparatus of FIGURE 1. Clutch 35 is then engaged and, when the motor 21 is driven at a constant speed, the turntable T and the disc 29 of unit F will be driven at constant speed and the traverse block 38 and the balls 40 and 41 will be traversed radially outwardly of the disc 29 at a constant speed.

When the open coil forming operation is first started the drum 23 will be rotated at a relatively slow speed and the signal from the tachometer unit 66 will so control the current supplied to the motor 15 through the control unit 68 that the motor 15 will drive the roll 5 to feed the strip at the proper relatively slow lineal velocity. As the operation continues the traverse block 38 and balls 41 and 40 move radially outwardly of disc 29 and, as disc 29 rotates at a constant speed, the speed of the drum 23 and the tachometer unit 66 will be progressively increased. This increase, through control box 68, will progressively increase the speed of rotation of

motors

15 and 19 and effect a corresponding increase in the lineal speed of the strip S as it is fed to the turntable T.

As the speed of turntable T remains constant and the lineal speed of the strip progressively increases, the ratio between the speed of feed of the strip and the speed of rotation of the turntable will progressively change. The rate at which this progressive change is effected will determine the radial position on the turntable T at which each increment of length of the strip S will be laid down and thus Will control the space between the laps of the open coil. Changing the speed of traverse of the block 38 outwardly of the disc 29 will vary the rate of change in the ratio between the speed of feed of the strip and the speed of rotation of the turntable T and such change may be effected by regulation of the variable speed control unit 45 through the bandwheel 45 or other suitable means. Thus, the faster the feed screw shaft 35 is driven relative to the speed of the turntable motor 21 the faster will the block 38 traverse the disc 29 and the greater will be the rate at which the ratio between the speed of feed of the strip and speed of rotation of the turntable will change. It will be understood that the greater this rate of change the greater will be the spacing between the laps of the coil formed on the turntable and, by properly setting the variable speed control unit 45, the desired space between the laps of the open coil may be obtained for strip of any given thickness.

In the apparatus of FIGURES 1 and 3 the proper relation between the speed of feed of the strip and the speed of rotation of the open coil turntable to form an open coil having the desired spacing between the laps is effected largely by mechanical means. It is entirely practical, however, to effect the desired control of this relation through means which are largely electrical in nature and in FIGURE 4 I have diagrammatically illustrated such an arrangement. In this apparatus the strip S is fed through the bridle rolls 4 and 5, roll 5 being driven through shaft 75 by motor 76. The open coil turntable is not illustrated in this view but it will be understood that it will be driven by the open coil drive motor D the armature of which is indicated at 77 and the field coil at 78. A generator G having an armature 79 and a field coil 80 is driven by independent means (not shown) and its output is applied to the armature 77 of the turntable drive motor through line 81. The field 78 of the turntable drive motor is regulated by the regulator unit 82 and the field 80 of the generator G is regulated by the regulator unit 83.

The apparatus of FIGURE 4 is designed to feed the strip at a constant lineal velocity and to progressively reduce the speed of rotation of the open coil turntable at the proper rate to form the desired open coil thereon. Thus the motor 76 will be driven at a constant speed while the turntable motor D will operate at a progressively diminishing speed. This may be effected in various ways but, as illustrated, the strip feed motor 76 drives a tachometer generator unit 84 through a shaft 85 and the signal from this unit 84 is impressed upon the regulator unit 82 through line 86 while a similar signal is impressed upon the regulator unit 83 through line 87.

The open coil turntable motor D also drives a tachometer generator unit 88 through a shaft 89 which also extends to an adjustable variable speed control unit 90 which may be regulated as by a handwheel to vary the ratio between the speed of motor shaft 89 and the speed of shaft 91 which extends to a reduction gear unit 92. A clutch 93 is disposed in the output shaft 94 from reduction gear 92 which shaft is connected to move the contact arm 95 of the potentiometer P. The output of the tachometer generator 88 is connected by line 96, in which the potentiometer P is interposed, to the regulator unit 83 of the generator G. A signal corresponding to the voltage output of generator G is applied to the turntable drive motor regulator unit 82 through line 98 and another signal, corresponding to the armature current of motor D, is also applied to regulator 82 through line 97. The combination of these two signals will provide a counter E.M.F. feed-back to unit 82. The main current supply lines to

field regulators

82 and 83 are indicated at 99 and 100; respectively.

In the operation of the apparatus just described, the open coil turntable drive motor field regulator 82 acts to keep the back of motor D at a constant value. The output of regulator 82 is connected to the field 78 of motor D through line 101 and is controlled by three input signals, first, a signal through line 86 from the tachometer 84 corresponding to the speed of strip feed; second, a signal through line 98 from generator G which is proportional to the voltage applied to the loose coil turntable motor D; and third, a signal through line 97 which is proportional to the armature current in the armature 77 of motor D from the generator G. This control functions to maintain the speed of motor D, and the open coil turntable in a definite relation to the rate of strip feed which is established by the speed of rotation of motor 76 and bridle roll 5.

The generator regulator 83 receives a strip speed signal from the tachometer unit 84 through line 87 and a turntable speed signal from the tachometer unit 88 through the line 96 and potentiometer P. At the beginning of an open coiling operation the clutch 93 is released and the contact arm 95 of the potentiometer P is set in counter-clockwise direction (as seen in FIGURE 4) to its starting position. In this position a maximum of resistance is interposed in the line 96 by the potentiometer P. As the motor D and the turntable T rotate, however, the contact arm 95 is moved progressively in clockwise direction and decreases the resistance interposed by potentiometer P in line 96' with consequent increase in the voltage applied to regulator 83 through line 96 and reduction in the voltage applied to the generator field 80 through line 102.

Thus, as the open coiling operation continues and the motor D rotates, the strength of the field 30 of generator G will be progressively reduced with corresponding reduction in the output of generator G and the speed of turntable motor D. Due to the progressive reduction in speed of motor D the rate of travel of the contact arm 95 of potentiometer P will not be constant but will be diminishing in nature. As has been previously explained, the diminishing rate at which the speed of the turntable drive means is reduced effects the formation of a coil having uniform spacing between the laps thereof. By properly regulating the variable speed control unit 90 the rate of travel of contact arm 95 may be varied to obtain the desired space between laps for the particular strip thickness being handled.

"From the above description of several embodiments of my invention it will be seen that I have provided extremely flexible apparatus for forming \open coils from tight wound coils without the use of any spacer strands or the like and which is subject to such accurate control that large open coils may be formed at an extremely rapid rate and with great accuracy of lap spacing. Although I have described the illustrated embodiments of my invention in considerable detail it will be understood that numerous modifications and variations may be made in the form and arrangement of the various elements which make up my improved apparatus. Therefore, I do not wish to be limited to the particular equipment herein shown and/or described, but claim as my invention all 75 embodiments thereof coming within the scope of the appended claims.

I claim:

1. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; variable speed turntable drive means for rotating said turntable on its vertical axis; means for feeding strip toward said turntable at a substantially constant lineal velocity; means for progressively reducing the speed of said turntable drive means at a diminishing rate which diminishes more rapidly than would be required to produce a tight coil whereby a space is formed between adjacent laps of the coil; and means for adjustably varying said rate at which the speed of said turntable drive means is reduced whereby the desired lap spacing of the open coil may be obtained for strip metal of different thicknesses.

2. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; variable speed turntable drive means; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element; means for rotating said driving element at a speed proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for controlling the speed of said turntable drive means; and driving connections from said turntable drive means to said adjustable means and adapted to actuate said adjustable means to effect progressive variation in the speed of said driven element.

3. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; variable speed turntable drive means; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element; means for rotating said driving element at a speed proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for controlling the speed of said turntable drive means; driving connections from said turntable drive means to said adjustable means and adapted to actuate said adjustable means to effect progressive variation in the speed of said driven element; and means in said driving connections for adjustably varying the ratio between the speed of said turntable drive means and the speed of actuation of said adjustable means.

4. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element; means for rotating said driving element at a speed proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for controlling the speed of said electric motor; and driving connections from said electric motor to said adjustable means adapted to actuate said adjustable means to effect progressive variation in the speed of said driven element.

5. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element; means for rotating said driving element at a speed proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for controlling the speed of rotation of said electric motor; driving connections from said electric motor to said adjustable means adapted to actuate said adjustable means to effect progressive variation in the speed of said driven element; said driving connections including means for adjustably varying the ratio between the speed of said electric motor and the speed of actuation of said adjustable means.

6. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit having a driving element, a driven element, and adjustable means for effecting driving connection between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a substantially constant speed; control means responsive to the speed of said driven element for controlling the speed of rotation of said electric motor; and driving connections from said electric motor to said adjustable means for effecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively changed during operation of said motor to rotate said turntable.

7. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable at a substantially constant lineal velocity; a variable speed unit having a driving element, a driven element, and adjustable means for effecting driving connection between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a substantially constant speed; control means responsive to the speed of said driven element for controlling the speed of rotation of said electric motor; driving connections from said electric motor to said adjustable means for effecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively changed during operation of said motor to rotate said turntable; said driving connections including means for adjustably varying the ratio between the speed of said electric motor and the speed of actuation of said adjustable means.

8. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable in a vertical plane at a substantially constant lineal velocity; vertically adjustable edge guide means for positioning the bottom edge of said strip relative to said turntable; a variable speed unit having a driving element, a driven element, and adjustable means for eflFecting driving connection between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a substantially constant speed proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for varying the speed of rotation of said electric motor; and driving connections from said electric motor to said adjustable means for effecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively changed during operation of said motor to rotate said turntable.

9. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; a variable speed electric motor connected to drive said turntable; means for feeding strip toward said turntable at a substantially constant lineal velocity; vertically adjustable edge guide means for positioning the bottom edge of said strip relative to said turntable; a variable speed unit having a driving element, a driven element, and adjustable means for effecting driving connection between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a substantially constant speed directly proportional to the lineal speed of the strip being fed to the turntable; control means responsive to the speed of said driven element for varying the speed of rotation of said electric motor; driving connections from said electric motor to said adjustable means for eltecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively changed during operation of said motor to rotate said turntable; said driving connections including means for adjustably varying the ratio between the speed of said electric motor and the speed of actuation of said adjustable means.

10. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; drive means for rotating said turntable; means for feeding strip toward said turntable; drive means for said strip feeding means; control means for said drive means adapted progressively to change the ratio between the speed of feed of the strip and the speed of rotation of said turntable during the forming of an open coil thereon at a rate of change different from the rate that would be required to produce a tight coil on said turntable; and means for adjustably varying said rate at which said ratio between the speed of feed of the strip and the speed of rotation of said turntable is changed by said control means.

11. -In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; means for rotating said turntable at a substantially constant speed; means for feeding strip toward said turntable; means for progressively increasing, -at a constant rate greater than the rate of increase which would be required to produce a tight coil, the speed of feed of said strip whereby the laps of the coil being formed will be spaced apart; and means for adjustably varying said rate at which the speed of feed of said strip is progressively increased whereby the desired lap spacing of the open coil may be obtained for strip metal of different thicknesses.

12. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; constant speed turntable drive means; means for feeding strip toward said turntable at a progressively increasing lineal velocity; 2. variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element; means for rotating said driving element at a speed proportional to the speed of rotation of said turntable; control means responsive to the speed of said driven element for controlling the speed of said means for feeding strip toward said turntable; and driving connections from said turntable drive means to said adjustable means and adapted to actuate said adjustable means to effect progressive variation in the speed of said driven element.

13 13. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; constant speed turntable drive means; means for feeding strip toward said turntable at a progressively increasing lineal velocity; at

variable speed unit including a driving element, a driven element, and adjustable means for varying the speed of said driven element relative to that of said driving element, means for rotating said driving element at a speed proportional to the speed of rotation of said turntable; control means responsive to the speed of said driven element for controlling the speed of said means for feeding strip toward said turntable; driving connections. from said turntable drive means to said adjustable means and adapted to actuate said adjustable means to effect progressive vriation in the speed of said driven element; and means in said driving connection for adjustably varying the ratio between the speed of said turntable drive means and the speed of actuation of said adjustable means.

14. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; means for rotating said turntable at a constant speed; variable speed strip feeding means for feeding strip toward said turntable in a vertical plane at a progressively increasing lineal velocity during forming of an open coil on said turntable; a variable speed uni-t having a driving element, a driven element, and adjustable means for effecting driving connection between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a speed proportional to the speed of rotation of said turntable; control means responsive to the speed of said driven element for varying the speed of said strip feeding means; and driving connections from said means for rotating said turntable to said adjustable means for effecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively increased during rotation of said turntable.

15. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which the open coil is adapted to be formed; means for rotating said turntable at a constant speed; variable speed strip feeding means for feeding strip toward said turntable in a vertical plane at a progressively increasing lineal velocity during forming of an open coil on said turntable; a variable speed unit having a driving element, a driven element, and adjustable means for efiecting driving connections between said driving and driven elements whereby the speed of said driven element relative to that of said driving element may be varied; means for rotating said driving element of said variable speed unit at a speed proportional to the speed of rotation of said tumtable; control means responsive to the speed of said driven element for varying the speed of said strip feeding means; and driving connections from said means for rotating said turntable to said adjustable means for effecting driving connection between said driving and driven elements adapted to actuate said adjustable means whereby the speed of said driven element will be progressively increased during rotation of said turntable; said driving connections including means for adjustably varying the ratio between the speed of said turntable and the speed of actuation of said adjustable means.

-16. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; drive means for rotating said turntable; a pair of vertical axis bridle rolls disposed adjacent the periphery of said turntable and adapted to feed strip in a vertical plane toward said tumtable; drive means for one of said bridle rolls; edge guide means ahead of said bridle rolls for positioning the bottom edge of the strip relative to said bridle rolls and said turntable; control means for said drive means adapted progressively to change the ratio between the speed of feed of the strip and the speed of rotation of said turntable during the forming of an open coil thereon; and means for adjustably varying the rate at which said ratio between the speed of feed of the strip and the speed of rotation of said turntable is changed by said control means.

17. In combination in apparatus for forming an open coil of strip metal, a vertical axis turntable on which an open coil is adapted to be formed; an electric motor connected rotatably to drive said turntable; feed roll means for feeding strip toward said turntable; an electric motor for driving said feed roll means to feed said strip; means for varying the relative speed of one of said electric motors at a rate which will form an open coil on said turntable; and means for adjustably varying the rate at which said speed of said one of said motors is varied.

References Cited in the file of this patent UNITED STATES PATENTS 2,336,754 Schelhammer et al Dec. 14, 1943 2,660,380 B. G. Blackman et a1. Nov. 24, 1953 3,008 663 C C. Blackman et a1. Nov. 14 1961