Strip winding apparatus
United States Patent Daves [45] Apr. 22, 1975 STRIP WINDING APPARATUS [75] Inventor: Howard W. Daves, Pittsburgh, Pa.  
 [73] Assignee: Aluminum Company of America, Pittsburgh, Pa.  
 [22] Filed: Aug. 18, 1972 [21] Appl. No.: 281,965  
 [52] US. Cl. 242/56.9; 242/72 R [51] Int. Cl B65h 19/04 [58] Field of Search 242/569, 72, 72 B [56] References Cited UNITED STATES PATENTS 1,297,809 3/1919 Dixon ct a1 242/72 B FOREIGN PATENTS OR APPLICATIONS 1,143,074 1/1963 Germany 242/72 B 11/1955 United Kingdom 242/72 8/1967 United Kingdom 242/56.9  
 Primary E.\&#39;aminer.lohn W. Huckert Assistant E.\&#39;aminer,lohn M. Jillions Attorney, Agent, or F irmGleim &amp; Tritle [57] ABSTRACT Apparatus for maintaining equal winding tension on all strips while a plurality of coils of strip material are wound simultaneously on individual cores. The cores are mounted for rotation on a mandrel having a plurality of side-by-side expandable mandrel sections. Each section includes a wall portion movable relative to the mandrel body for securing a core thereto when said tension is at a desired value and at other times, permitting slippage of the core relative to the rotation of the mandrel.  
 3 Claims, 2 Drawing Figures PATENIEUAPRMQYE,  
 sum 1 a;  
 STRIP WINDING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to the winding of strip or strip-like material and, more particularly, to means for winding with equal tension a plurality of individual coils of strip or striplike material on a single mandrel.  
  Heretofore, various devices have been utilized for receiving a relatively wide web or sheet of material and slitting the material longitudinally into strips which are then wound on individual cores to form individual coils of the strip material. Such prior art devices have included various means to control the tension of the individual strips during the winding operation in an effort to insure uniformity of quality of the strip material in the individual coils as well as uniformity of size thereof. Heretofore, it has been found necessary to provide a plurality of separate tension control means for controlling the winding tension of each of the individual coils in order to obtain such uniformity. Additionally, it has been necessary heretofore to mount adjacent coils in a staggered manner on at least two mandrels particularly when winding coils of relatively large diameter in order to provide room and avoid mechanical interference between the individual coils and their respective tension control means.  
 SUMMARY Accordingly, it is a principal object of the present invention to provide improved means for controlling winding of coils of strip material on individual cores all mounted on a single mandrel. This is accomplished in accordance with the invention by the provision of a mandrel having a plurality of expandable sections mounted in side-by-side relationship along the longitudinal axis of the mandrel. Each of said sections has a wall portion movable radially relative to other portions of the mandrel responsive to variations in pressure of a single source of pressurized fluid for selectively establishing a driving and/or slipping relationship between individual cores and the mandrel.  
  These and other objects and advantages will become apparent from the following description taken in connection with the following drawings in which FIG. 1 is a cross sectional view of one of the mandrel sections embodying the present invention; and  
  FIG. 2 is a view of a mandrel having a plurality of sections according to the embodiment of FIG. 1 and showing the individual sections mounted in side-by-side relationship.  
  In the drawings a mandrel embodying the present invention is indicated generally at 10. The mandrel includes an arbor portion 11 which is adapted to be mounted for rotation in a suitable drive housing of a winding device which is not shown since the details of such device are not necessary to the understanding of the present invention.  
  The mandrel extends axially along its longitudinal axis to an extent sufflcient to accommodate a desired number of mandrel sections 12.  
  The mandrel also includes a central bore 13 which is closed at one end by a suitable plug 14, and terminates at a port 15 at the opposite end for receiving pressurized fluid from a supply conduit 16.  
  It is to be understood that each of the individual sections 12 is of like construction and each functions in the same way so that the structure and function of only one of such sections will be described herein. As is best shown in FIG. 1, that portion of the mandrel that extends beyond the arbor portion and supports the individual sections is shown at 10a. Mand-rel portion 10a is cross-bored relative to bore 13 to receive a cylinder 17 which is closed at one end and retained within mandrel portion 10a by members 18, 19, 20. A piston 21 is slid ably mounted within cylinder 17 for reciprocation therein. Piston 21 includes a rod portion 22 that extends through ari opening in the unclosed end of cylinder 17 and has connected thereto an end portion 23.  
  Members 18 and 19 are provided with central bores 18a, 19a for receiving the head of a bolt 24 extending through an opening in member 18 and threadedly connected to piston 21. A spring 25 is interposed between member 18 and the head of bolt 24 for urging piston 21 v radially inward toward the center of mandrel portion One or more arcuate wall portions 26 are hingedly connected to the mandrel portion 10a at pivots 27 and the opposite end of wall portion 16 is suitably shaped to bear against end portion 23 of piston 21.  
  Wall portions 26 are also connected to mandrel portion 10a by a bolt 28 extending through a portion of wall portion 26 and permitting relative movement therebetween. A spring 29 is interposed between the head of bolt 28 and a portion of wall portion 26 to urge wall portion 26 inwardly toward the central portion of mandrel portion 10a.  
  Pressurized fluid is supplied to conduit 16 at constant pressure by a pump 30 and a directional control valve 31 from a reservoir 32. Conduit 16 is connected by a branch conduit 33 to an hydraulic cylinder 34. A check valve 31a is shown located between the pump 30 and valve 31 to provide a unidirectional flow of fluid from the pump to the valve 31. The pump and the reservoir can be quite small because the reservoir merely provides replacement fluid in the event of minor leakage of fluid from the system.  
  A piston member 35 extends through one end of cylinder 34 and is adjustably positioned therein by a rack 36 and a pinion 37 by means of a reversable direct current motor 38.  
  A core 39 is indicated by the broken lines in FIGS. 1 and is mounted on one of the sections 12 of the mandrel prior to a coil winding operation. It will be understood that as many cores are mounted on as many individual sections 12 as there are individual strips of material to be wound into coils.  
  Means sensing the winding tension of individual coils includes a transducer 40 which converts the sensed tension into an electrical signal. Such signal is fed into a controller 41 by an electrical connector 42. Controller 41 is of a known type which compares such signal with a preselected value and produces another signal if the sensed signal is greater than or less than said preselected value. Signals produced by controller 41 are communicated to motor 38 by electrical connections 43, 44. A pressure transducer 45 senses the value of pressure in conduit 33 and produces a corresponding signal which is communicated to the controller by an electrical connector 46.  
  In operation sheet material is divided into a desired number of strips by conventional slitting means. A corresponding desired number of cores desired width are individually mounted on the individual sections 12 of a mandrel l embodying the present invention. The arbor portion 11 of the mandrel is rotatably mounted in the drive housing of a conventional winding machine and is driven thereby after the supply conduit means 16 is connected to port 15. Pressurized fluid is supplied by pump 30 to bore 13 and to each of the pistons 21 of the individual sections 12, thus causing the piston 21 and the wall portions 26 to move radially outward relative to a core 39 mounted on an individual section and thereby connecting the mandrel section in driving relationship with the core. Since all pistons of the individual sections receive pressurized fluid from the central bore 13, such driving connection between all individual mandrel sections and the individual cores mounted therein is established simultaneously.  
  As the winding of the strips into coils proceeds, unequalities in winding tension will result in sag or slack appearing in one or more of the strip. When this occurs, the inequality is sensed by sensor 40 and an appropriate signal is transmitted to the controller 41 which in turn causes operation of motor 38 to cause slow rotation of pinion 37 in a clockwise direction. Such rotation of the pinion causes corresponding movement of rack 36 to partially withdraw piston member 35 from cylinder 34 and thereby increase the effective volume thereof. Such increase in the effective volume of cylinder 34 causes a slow and controlled reduction in the fluid pressure in bore 13 and received by the pistons 21 of the several mandrel sections 12. At  
 . some time during the occurrence of this slow and controlled reduction of pressure, the arcuate wall portions 26 of a mandrel section carrying a tight coil strip will retract sufficiently to permit the core of the right coil to slip until the sag or slack in the loose coil or coils is taken up and equal winding tensions are restored. As  
 such slippage occurs and as equal winding tensions are approached, such conditions are also sensed by sensor 40 which, as indicated heretofore, compares such conditions with preselected conditions and makes a corrective signal which is transmitted to the direct current motor 38 in the form of a signal causing rotation of the motor and pinion 37 in a counterclockwise direction, thus tending to reduce the effective volume of hydraulic cylinder 34, and thus restore the pressure in conduit 16 to the desired value corresponding to the preselected pressure fixed by pressure transducer 45. This also results in a slow and controlled change in pressure which thus slowly increases until it approaches the preselected value. When the pressure reaches a preselected value, this condition is sensed by pressure transducer 45 which communicates a signal via connection 46 to the controller 41 so as to stop the operation of motor 38 when the pressure in the conduit 16 has been restored to the preselected value.  
 While a particular embodiment of the invention has been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention and it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.  
 What is claimed is:  
  1. Strip winding apparatus for winding simultaneously and under equal tension individually a plurality of strips of material on individual cores comprising in combination a rotatable mandrel body having a plurality of sections each having a core-supporting member movable radially relative to the axis of rotation of said body and resiliently biased inwardly toward said axis,  
 pressure-actuated means operatively connected to each of said members and individually moving said core-supporting members under the influence of a pressurized fluid,  
 a core member supported by and releasably frictionally engaged in driven relationship by one of said core-supporting members for winding a strip of material onto said core member,  
 another core member supported by and releasably frictionally engaged in driven relationship by another of said core-supporting members for winding another strip of material onto said another core member,  
 a passageway within said body connected to each of said pressure-actuated means in fluid communication relationship,  
 means including a conduit supplying pressurized fluid at a preselected pressure during operation of the apparatus connected to said passageway,  
 means sensing and comparing tension of said strips of material and producing a signal when the tension of the individual strips is unequal, and  
 pressure influencing means connected to said signal producing means and to said supply means and effecting a pressure change from said preselected pressure and allowing one of said core members to slip individually relative to said body until the tension of both strips of material becomes equalized.  
  2. Apparatus according to claim 1 wherein said pressure influencing means reduces the pressure of said fluid below said preselected pressure when the tension of said individual strips is unequal and thereafter restores said pressure to said preselected value when the tension of said individual strips become equalized.  
  3. Apparatus according to claim 1 wherein said pressure influencing means reduces the pressure of said fluid to a value less than that of said preselected pres-