Abstract An apparatus for controlling a let-off motion in a loom having a let-off motion motor includes a tension detector for detecting a warp tension to produce a tension correction signal, a control unit responsive to the tension correction signal for producing a speed signal, a driving amplifier for controlling the let-off motion motor in response to the speed signal, a warp coil diameter detector for issuing a warp coil diameter correction signal inversely proportional to the diameter of a warp coil on a beam to the driving amplifier, and a normal-reverse rotation control unit responsive to the warp coil diameter correction signal for selectively applying prescribed normal- and reverse-rotation signals dependent on a rotation command to the driving amplifier. With this arrangement, the motor is rotated at a desired constant speed for feeding out or rewinding the warp yarn for a desired length irrespectively of the warp coil diameter. In an inching mode of operation, the motor is rotated in a normal or reverse direction for an interval equivalent to one pick each time a main shaft of the loom turns past a certain rotational angle, so that the warp yarn is kept under a desired tension.
An apparatus for controlling a let-off motion in a loom having a let-off motion motor, comprising: (a) a tension detector for detecting a warp tension to produce a tension correction signal; (b) a control unit responsive to said tension correction signal for producing a speed signal; (c) a driving amplifier for controlling the let-off motion motor in response to said speed signal; (d) a warp coil diameter detector for issuing a warp coil diameter correction signal inversely proportional to the diameter of a warp coil on a beam to said driving amplifier; and (e) a normal-reverse rotation control unit responsive to said warp coil diameter correction signal for selectively applying prescribed normal- and reverse-rotation signals dependent on a rotation command to said driving amplifier, said normal-reverse rotation control unit comprising an inching correction driver for temporarily rotating the let-off motion motor at a number of RPM dependent on the diameter of the warp coil on the beam and weaving conditions each time a main shaft of the loom turns past a preset rotational angle while the loom is in normal and reverse inching modes of operation.
Claim 2
Independent Claim
186 words
An apparatus for controlling a let-off motion in a loom having a let-off motion motor, comprising: (a) a tension detector for detecting a warp tension to produce a tension correction signal; (b) a control unit responsive to said tension correction signal for producing a speed signal; (c) a driving amplifier for controlling the let-off motion motor in response to said speed signal; (d) a warp coil diameter detector for issuing a warp coil diameter correction signal inversely proportional to the diameter of a warp coil on a beam to said driving amplifier; and (e) a normal-reverse rotation control unit responsive to said warp coil diameter correction signal for selectively applying prescribed normal- and reverse-rotation signals dependent on a rotation command to said driving amplifier, said normal-reverse rotation control unit comprising an inching correction driver for temporarily rotating the let-off motion motor at a number of RPM dependent on the diameter of the warp coil on the beam and weaving conditions each time a main shaft of the loom turns past a preset rotational angle while the loom is in normal and reverse inching modes of operation.
Claim 3
Dependent Claim
38 words
An apparatus according to claim 1, wherein said inching correction driver temporarily rotates said let-off motion motor for an interval equivalent to one pick each time said main shaft of the loom turns past said preset rotational angle.
Claim 4
Dependent Claim
53 words
An apparatus according to claim 1, wherein said normal-reverse rotation control unit comprises a digital circuit including an encoder operatively connected to said let-off motion motor and a central processing unit for calculating a signal indicative of the diameter of the warp coil on the beam from an output signal from said encoder.