Method of knitting an elastomeric yarn into a circularly knitted fabric
View Patent ↗A method for circularly knitting an elastomeric yarn into a knitted fabric is provided. The method includes: operating a circular knitting machine at a machine rate, retaining a free end of the elastomeric yarn in a substantially relaxed condition, and taking up the free end into the circular knitting machine while feeding the elastomeric yarn at a first feed rate. The first feed rate maintains the elastomeric yarn in the substantially relaxed condition. The circular knitting machine continues to operate at the machine rate during the taking up of the free end.
1. A circular knitting machine comprising:
a plurality of needles moving a substantially constant knitting speed;
a drive for positively feeding an elastomeric yarn to said plurality of needles, said drive being operable at a first feed rate;
a guide being movable with respect to said plurality of needles, said guide preventing said elastomeric yarn from being taken-up by said plurality of needles in a first position and allowing said elastomeric yarn to be taken-up by said plurality of needles in a second position; and
a controller for controlling said drive and said guide, said controller moving said guide from said first position to said second position while operating said drive at said first feed rate,
wherein said first feed rate is substantially equal to or greater than a rate with which said elastomeric yarn is drawn-in by said plurality of needles while moving at said substantially constant knitting speed.
2. The machine as in claim 1 , wherein said controller controls said drive to operate at said first feed rate until at least one needle of said plurality of needles knits a stitch.
3. The machine as in claim 1 , wherein said drive is operable at a second feed rate, said second feed rate being less than said rate with which said elastomeric yarn is drawn-in by said plurality of needles.
4. The machine as in claim 3 , wherein said second feed rate is a constant feed rate or a variable feed rate.
5. The machine as in claim 1 , wherein said drive is a servo-motor or a stepper motor.
6. The machine as in claim 1 , further comprising a severing device controlled by said controller to sever said elastomeric yarn from said plurality of needles.
7. The machine as in claim 6 , wherein said controller operates said drive at said first feed rate for a predetermined period of time prior to controlling said severing device to sever said elastomeric yarn.
8. The machine as in claim 6 , further comprising a suction hood on said cylinder, said suction hood generating a negative pressure sufficient to maintain a severed end of said elastomeric yarn in a desired location on said cylinder.
9. The machine as in claim 1 , further comprising a suction hood disposed on said cylinder, said suction hood generating a negative pressure sufficient to maintain a severed end of said elastomeric yarn in a desired location on said cylinder.
10. A yarn feeding system for a circular knitting machine, comprising:
a drive for positively feeding an elastomeric yarn to the circular knitting machine, said drive being operable at a first feed rate;
a guide being movable with respect to the circular knitting machine, said guide for preventing said elastomeric yarn from being taken-up by the circular knitting machine in a first position and allowing an end of said elastomeric yarn to be taken-up by the circular knitting machine in a second position;
a suction hood for generating a negative pressure sufficient to maintain said end in a desired location on the circular knitting machine during movement of said guide; and
a controller for controlling said drive and said guide, said controller moving said guide from said first position to said second position while operating said drive at said first feed rate,
wherein said first feed rate is substantially equal to or greater than a rate with which said elastomeric yarn is drawn-in by the circular knitting machine.
11. The system as in claim 10 , wherein said controller controls said drive to operate at said first feed rate until the circular knitting machine knits at least one stitch.
12. The system as in claim 10 , wherein said drive is operable at a second feed rate, said second feed rate being less than said rate with which said elastomeric yarn is drawn-in by the circular knitting machine.
13. The system as in claim 12 , wherein said second feed rate is a constant feed rate or a variable feed rate.
14. The system as in claim 10 , wherein said drive is a servo-motor or a stepper motor.
15. The system as in claim 10 , further comprising a severing device controlled by said controller to sever said elastomeric yarn from the circular knitting machine.
16. The system as in claim 15 , wherein said controller operates said drive at said first feed rate for a predetermined period of time prior to controlling said severing device to sever said elastomeric yarn.