Method of spinning-in yarn on an operating unit of a rotor spinning machine and a device for carrying out the method

A method of spinning-in yarn at a spinning unit of a rotor spinning machine, said method comprising:

• steps of yarn preparation, steps of spinning rotor preparation, and final spinning-in steps;
• said steps of yarn preparation comprising detection of a yarn end on a bobbin or preparation of an auxiliary yarn if spinning-in on an empty tube, unwinding and metering a yarn length required for the spinning-in, placing the yarn into a path in which it is unclamped by rollers of a yarn draw-off mechanism, and introducing the yarn end into a yarn delivery tube extending from a spinning rotor;
• said steps of spinning rotor preparation comprising opening the spinning unit from its operative spinning position to a cleaning position, cleaning the spinning rotor in a stopped position thereof, and closing the spinning unit to its operative spinning position;
• said final spinning-in steps comprising starting sliver supply to a fiber singling-out device, leading singled-our fibers from the singling-out device away from the spinning rotor for a predetermined time interval, bringing the yarn end into contact with a collecting groove in the spinning rotor, and starting yarn draw off and winding;
• and
• wherein at least one of said final spinning-in steps is synchronized with said closing of the spinning unit so as to commence at a set predetermined time interval measured from said closing step, said remaining final spinning-in steps being carried out in a timed relationship with the synchronized final spinning step;
• and
• wherein at the start of said closing operation said step of leading singled-out fibers from the singling-out device away from the spinning rotor is started, and at the completion of said closing operation said step of starting sliver supply to the fiber singling-out device is started, said step of leading singled-out fibers away from the spinning rotor is stopped, and said step of bringing the yarn end into contact with the collecting groove in the spinning rotor and yarn winding are started.

A method of spinning-in yarn at a spinning unit of a rotor spinning machine, said method comprising:

• steps of yarn preparation, steps of spinning rotor preparation, and final spinning-in steps;
• said steps of yarn preparation comprising detection of a yarn end on a bobbin or preparation of an auxiliary yarn if spinning-in on an empty tube, unwinding and metering a yarn length required for the spinning-in, placing the yarn into a path in which it is unclamped by rollers of a yarn draw-off mechanism, and introducing the yarn end into a yarn delivery tube extending from a spinning rotor;
• said steps of spinning rotor preparation comprising opening the spinning unit from its operative spinning position to a cleaning position, cleaning the spinning rotor in a stopped position thereof, and closing the spinning unit to its operative spinning position;
• said final spinning-in steps comprising starting sliver supply to a fiber singling-out device, leading singled-out fibers from the singling-out device away from the spinning rotor for a predetermined time interval, bringing the yarn end into contact with a collecting groove in the spinning rotor, and starting yarn draw off and winding;
• wherein at least one of said final spinning-in steps is synchronized with said closing of the spinning unit so as to commence at a set predetermined time interval measured from said closing step, said remaining final spinning-in steps being carried out in a time relationship with the synchronized final spinning step;
• and
• wherein during said closing operation said step of leading singled-out fibers from the singling-out device away from the spinning rotor is started, and at the completion of said closing operation said step of starting sliver supply to the fiber singling-out device is started, said step of leading singled-out fibers away from the spinning rotor is stopped, and said step of bringing the yarn end into contact with the collecting groove in the spinning rotor and yarn winding are started.

An open end spinning machine having individual spinning units for spinning yarn, comprising:

• means for performing steps of yarn preparation, means for performing steps of spinning rotor preparation, and means for performing final spinning-in steps;
• said steps of yarn preparation comprising detection of a yarn end on a bobbin or preparation of an auxiliary yarn if spinning-in on an empty tube, unwinding and metering a yarn length required for the spinning-in, placing the yarn into a path in which it is unclamped by rollers of a yarn draw-off mechanism, and introducing the yarn end into a yarn delivery tube extending from a spinning rotor;
• said steps of spinning rotor preparation comprising opening the spinning unit from its operative spinning position to a cleaning position, cleaning the spinning rotor in a stopped position thereof, and closing the spinning unit to its operative spinning position;
• said final spinning-in steps comprising starting sliver supply to a fiber singling-out device, leading singled-out fibers from the singling-out device away from the spinning rotor for a predetermined time interval, bringing the yarn end into contact with a collecting groove in the spinning rotor, and starting yarn draw off and winding;
• each said spinning unit comprising a sensor disposed to detect the position of a cover of said spinning unit, said sensor in communication with a control unit, said control unit synchronizing said final spinning-in steps with closing of said cover detected by said sensor such that at least one of said final spinning-in steps is synchronized by said control unit with closing of the spinning unit so as to commence at a set predetermined time interval measured from the detected closing step, the remaining final spinning-in steps being carried out in a timed relationship with the synchronized final spinning step.