US3746273A

US3746273A - Reeling and unreeling device

Info

Publication number: US3746273A
Application number: US00192256A
Authority: US
Inventors: R Elsworth
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1971-10-26
Filing date: 1971-10-26
Publication date: 1973-07-17
Anticipated expiration: 1990-07-17

Abstract

The disclosure relates to a device for reeling and unreeling a web or filiment under constant tension. The reeling mandrel is mounted on a sliding frame which is positively biased. The mandrel is driven by an electric motor mounted on the frame and any movement of the frame varies the rotational speed of the motor, whereby the speed of the motor is reduced as the diameter of the roll increases. This assures a constant tension on the web as it is reeled or unreeled.

Description

United States Patent Elsworth July 17, 1973 [54] REELING AND UNREELlNG DEVICE 2,775,414 12/1906 Rush 242/755 Inventor: Robert M Elsworth, Loudonvme 3,279,719 10/1966 Kabelltz 242/7553 N.Y. Primary ExaminerGeorge F. Mautz Assigneei General Electric p y, Assistant ExaminerEdward J. McCarthy Waterford, Attorney-Donald J. Voss [22] Filed: Oct. 26, 1971 211 Appl. No.2 192,256 1 ABSTRACT The disclosure relates to a device for reeling and un- 52 US. Cl. 242/7551 'sshhg a hhmshi hdsi sohsishi The 51 Int. Cl. B65h 25/02 'sshhg mandrel is "ishhisd a sliding frame which is 53 Field of Search 242/755 75.52 Psiiivs1Y hisssd- The "ishdisl is drive" by an electric 242/7553 7551 226/195 motor mounted on the frame and any movement of the frame varies the rotational speed of the motor, whereby 56] References Cited the speed of the motor is reduced as the diameter of the roll increases. This assures a constant tension on the 2 9 431 :I gT PATENTS 242/75 53 web as it is reeled or unreeled.

o 7 1,916,467 7/1933 Eger 242/75.5 X 10 Claims, 3 Drawing Figures Paiented July 17, 1973 3,746,273

2 Sheets-Sheet 1 Patented July 17, 1973 2 Shee ts-Sheet :3

FIG. 2.

REELING AND UNREELING DEVICE BACKGROUND OF THE INVENTION This invention relates to those devices which are intended to insure a constant tension on a web that is being reeled or unreeled during the processing or handling of a long indeterminate length of material. As the material is wound about a mandrel or other reeling device, its diameter increases, and although the rotational speed of the mandrel or other reeling device remains constant in terms of revolutions per minute, the speed of the winding in feet per minute at the periphery of the roll continues to increase. Therefore some means is necessary to constantly reduce the rotational speed of the mandrel as the size of the roll increases. Conversely, when unreeling the material, it is also necessary to gradually increase the rotational speed of the mandrel as the material web is paid out.

Reeling and unreeling devices currently in use in the prior art involve elaborate electrical equipment to attempt to synchronize the feeding and take-up speeds of the reeling and unreeling devices. This is usually done by attaching a selsyn generator to the output or calendar rolls and a selsyn receiver to the take-up or wind-up rolls. Electronic torque sensing circuits then attempt to superimpose corrections to hold the torque constant at a given speed.

The present invention, however, maintains a constant tension on the web that may be controlled at any rotational or peripheral speed. It is the tension on the web that is of paramount importance, not the torque or the wind-up or calendar rolls.

OBJECTS OF THE INVENTION It is therefore an object of this invention to provide an automatic device which will receive and roll up material for an indeterminate length with an inexpensive and simple control. The device regulates the winding speed to provide a controlled wind-up tension regardless of the diameter of the roll or speed of rotation. If the delivery of the indeterminate web is increased, the machine will accommodate the change in velocity while maintaining a constant tension on the material itself. The device is equally applicable to calendar or pay-out rolls as it is to the wind-up roll. The conversion from one to another is made by simply reversing the polarity of the drive means.

It is another object of this invention to provide a device for reeling and unreeling a web wherein the mandrel or spool is mounted on a sliding frame which is positively biased in a direction opposite to the direction of the pay-out or incoming material. It is another object of this invention to provide an electric drive means for the mandrel that is mounted on the sliding frame wherein any movement of the frame will vary the rotational speed of the drive motor. The positively biased sliding frame maintains a constant tension on the web itself. Any movement of the frame itself varies the rotational speed of the motor to reduce the peripheral speed of the material as the diameter of the roll increases.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagramatic and isometric view of a reeling and unreeling device constructed in accordance with my invention.

FIG. 2 is a detailed diagramatic and isometric view of the transmission means and tension means coupled to the sliding frame.

FIG. 3 is a diagramatic side view of a reeling and unreeling device constructed in accordance with my invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a web 11 of indeterminate length is being wound on a mandrel 12 in the direction indicated by arrow 13. The reeling and unreeling apparatus consists of two frames, a first fixed frame 14 and a second frame 15 which is mounted for reciprocal movement within frame 14 in the direction indicated by arrow 16. The second frame means 15 is guided by and suspended from a pair of parallel guides 17 and 18 which are firmly and fixedly attached to frame 14. The second frame means is suspended from brace members 19 and 20 from a pair of

low friction bearings

21 and 22. While the parallel guides 17 and 18 have been indicated in FIG. I as case hardened steel shafts, and while the bearing means 21 and 22 have been indicated as low friction bearings of the Thompson variety, it would be apparent to anyone skilled in the art to substitute a different type of guide means and low friction bearing means to allow for reciprocal movement of the frame means 15 within stationary frame I4. An example of such a guide would be conventional track and roller car assembly wherein the tracks would be mounted on the stationary frame 14 and the roller cars on movable frame 15.

Mandrel 12 is securely mounted for rotation within the upper portions 19a and 20a of the frame members 19 and 20. Any conventional bearing means may be employed to provide for the rotation and support of mandrel l2.

Mandrel 12 is driven by means of a sprocket 23, drive chain 24, and drive sprocket 25. The drive means for the assembly in this embodiment is an electric motor 26. The speed of motor 26 is controlled by a power supply and control device 27, translator 28 and transmission assembly 29 as will be hereinafter explained.

Transmission assembly 29 is comprised of a rack 30 and pinion gear 31 which cooperate in a conventional manner to turn reciprocal movement into rotary movement. The rack 30 is aligned parallel to the parallel guides 17 and 18.

The second frame means 15 is positively biased in the direction indicated by arrow 32. This is directly opposite to the direction of the reeling or unreeling web of material. Biasing means described in accordance with the preferred embodiment comprises a weight 33, a pair of

pulleys

34 and 35, and wire rope member 36 which is fixedly attached to frame I5 at point 37 and securely attached to the weight 33. Thus, it is apparent that the tension maintained on web II is constant regardless of the position of the movable frame 15. This tension is exerted by the weight of member 33 and may be varied depending upon the material to be reeled or unreeled, and the speed at which the reeling or unreeling is to take place.

Altemately, it would be possible to employ a constant torque spring means to positively bias the frame means 15 in one direction. The constant torque spring would provide a specific amount of pull or torque regardless of the elongation of the spring, and would therefore provide for constant tension regardless of the location of frame means 15.

HO. 2 is a perspective view of the speed control means used in this embodiment of the invention. The movable frame means 15 is mounted for reciprocation along the paths indicated by arrow 16. As the movable frame 15 reciprocates back and forth, the transmission means 30 and 31 translate that reciprocal movement into rotary movement at shaft 40. Translator 28 is a variable impedance device actuated by shaft 40. in the instant embodiment, it comprises a wire-wound variable resistor which regulates the power supply means 27. While a wire-wound variable resistor has been disclosed in the preferred embodiment, it is understood that any suitable type of variable impedance device could be used to translate the rotary motion of shaft 40 into a variable impedance for the control circuitry of the motor 26.

Motor 26 in the preferred embodiment is a compound or interpole DC motor which has a normally fixed voltage across the field coil, and a variable voltage impressed upon the windings of the armature. When a motor is running, the coils of the armature cut the lines of force from the field coils to generate an internal voltage or counter-emf. The sum of the counteremf and the resistance drop through the armature equals the impressed voltage from the external circuitry supplied from the power source 27. Consequently, the current taken is much larger when the motor is revolving slowly than when it is at its maximum speed. In order to increase the speed of the motor, the armature current is increased by decreasing the dampening of the silicon rectifier control circuitry and this causes the armature to increase its speed since the field is held constant. This produces more torque which increases the speed until the back voltage allows just the right current to flow to carry the existing load. The control circuitry for varying the voltage supplied to motor 26 is contained within the power supply 27, and is regulated by the translator 28. The direct current for the motor is also supplied by power source 27. While a direct current motor has been described with regard to the preferred embodiment, it would be entirely possible to substitute a wound-rotor or brushshifting AC motor which would provide for the proper and variable speed control necessary for the invention. Alte'mately, it would be possible to connect the output of shaft 40 to a mechanical linkage and use that to regulate the speed of an internal combustion motor if the device were to be used in a remote location where electrical service was not convenient.

Referring back to FIG.v 1, when the device is set for normal operation, the variable impedance means 28 is placed in the middle of its impedance range, and the movable frame means 15 is placed midway between its outer limits of travel within frame 14. As the drive motor 26 begins to drive mandrel 12, a tension is exerted on web 11. This tension is essentially-equivalent to the tension exerted along the reciprocal path by cable 36 as indicated at arrow 32. As indicated previously, if more tension is desired, the size of weight 33 is increased. As the diameter of the roll indicated at 38 increases, the speed of the motor is gradually reduced. This reduction in speed is brought about in the following manner. As the diameter 38 grows, the peripheral speed of web 11 will increase, thereby slightly increasing the tension on the material. This slight increase in tension will cause the movable frame means 15 to move in the direction indicated by arrow 39, and this reciprocal movement of the frame means 15 will cause a slight rotary movement of the spur gear 31. This change in rotary movement will vary the impedance presented by translator 28, and thereby vary the speed of the DC motor 26 through the power supply means 27.

If for some reason the web of material 11 should go slack, the tension exerted by weight 33 in the direction of arrow 32 will cause the movable frame means 15 to move in the direction indicated by arrow 32. This change in reciprocal direction will again be reflected as the reciprocal movement is translated into rotary movement by means of the transmission means 29. This rotary movement is again translated by translator 28 into a variable impedance for varying the speed of motor 26. In this case, the speed of motor 26 would be increased to take up the slack in the material web 11.

Limit switches may be provided in translator 28 at the extreme opposite ends of the rotary movement allowed by the rack and pinion transmission means 29. Thus if the web goes completely slack and the movable frame means 15 is drawn beyond its predetermined limit in the direction of arrow 32, the translator limit switch will interrupt the power supply to motor 26 and thereby stop the reeling operation.

Conversely, if the supply of material should suddenly stop, or if the unreeling device at the other end should suddenly freeze, the movable frame means 15 will be very quickly moved in the direction indicated by arrow 39 and the translator 28 would again interrupt the current supplied to motor 26. The potentiometer thereby provides both a safety feature and an automatic shutoff device.

If it is desired to use the device as an unreeling machine rather than a reeling machine, it is only necessary to change the polarity'of the current supplied to motor 26. This is accomplished by means of a simple switch (not shown) attached to power supply 27.

While specific means have been illustrated and specific examples and mentions given herein, it is to be understood that various modifications of the reeling and unreeling device would appear to one skilled in the art. Accordingly, it is understood that the present invention is not limited to the specific examples given for the specific examples given for the specific embodiment, but is to be limited only in accordance with the appended claims.

What is claimed is:

1. An apparatus for reeling and unreeling a web under constant tension comprising,

a. a first and second frame means, said second frame means being mounted for a substantially horizontal reciprocal movement within said first frame means,

b. a mandrel mounted on said second frame means for reeling and unreeling a web of material, said mandrel being rotated by a drive means,

c. sensing means for measuring the substantially hori zontal reciprocal movement of said second frame means, said sensing means controlling said drive means and varying the rotational speed of said mandrel in accordance with said reciprocal movement.

2. The apparatus of claim 1 wherein said second frame means is positively biased along the path of said reciprocal movement substantially opposite to the tension direction of the web.

3. The apparatus of claim 1 wherein said sensing means comprises a transmission means adapted to translate the reciprocal movement of said second frame means to rotational movement.

4. The apparatus of claim 3 wherein said drive means comprises an electric motor.

5. The apparatus of claim 4 which further comprises means responsive to said rotational movement of said transmission means to vary the armature strength of said electric motor.

6. The apparatus of claim 3 wherein said transmission means comprises a rack and pinion gear in operable arrangement, said rack being parallel to said reciprocal movement.

7. The apparatus of claim 6 wherein said first frame means.

Claims

1. An apparatus for reeling and unreeling a web under constant tension comprising, a. a first and second frame means, said second frame means being mounted for a substantially horizontal reciprocal movement within said first frame means, b. a mandrel mounted on said second frame means for reeling and unreeling a web of material, said mandrel being rotated by a drive means, c. sensing means for measuring the substantially horizontal reciprocal movement of said second frame means, said sensing means controlling said drive means and varying the rotational speed of said mandrel in accordance with said reciprocal movement.

7. The apparatus of claim 6 wherein said first frame means defines parallel guides, said second frame means being mounted on said guides for reciprocal movement.

8. The apparatus of claim 5 wherein said means responsive to said rotational movement comprises a variable impedance.

9. The apparatus of claim 8 wherein said impedance means comprises a variable resistor.

10. The apparatus of claim 2 wherein said means to positively bias said second frame means comprises an adjustable weight suspended from said first frame and adapted to exert a positive bias on said second frame means.