Apparatus for tension control of a flexible material during winding or unwinding from a drum or reel
AssigneeBeta Instruments Co., Ltd.
InventorOwen J. Orchard
Life of this patent
Estimating the term…
Abstract
Apparatus for controlling the tension of travelling filamentary material such as that being unwound from a drum or spool. It comprises a three phase induction motor for turning the drum or spool modified to have a high resistance rotor providing a torque speed characteristic of falling torque with increasing speed. The motor drive, and torque in either forward or reverse drive, is controlled by a pair of thyristor banks selectively triggered for forward and reverse drive modes by error signals representative of variation in tension from the required value.
Claims6
Apparatus for controlling the tension of travelling flexible materials during winding and unwinding processes comprising,
- an A.C. three phase induction electric motor coupled to a spool to rotate said spool,
- said spool having flexible material wound thereon and travelling flexible material extending from said flexible material on said spool,
- detector means for detecting changes in the tension of said travelling flexible material from a prescribed tension value, said detector means producing a signal representative of variation in the tension of said travelling flexible material from the prescribed tension value,
- control means for receiving said signal and operatively responsive to said signal to control the rotation of said electric motor to thereby maintain said tension of said travelling material at said prescribed tension value, and
- said control means includes a pair of thyristor banks selectively operable in response to said signal to effect rotation of said induction motor in a predetermined rotational direction to attain said prescribed tension value,
- said thyristor banks operable to vary the torque of said motor in said predetermined rotational direction to restore said tension of said travelling flexible material to said prescribed tension value by varying a voltage between a pair of phase windings of said motor connected between said thyristor banks.
Dependencies are inferred from the claim text.