Spinning station of an air-jet spinning machine and method for carrying out a piecing process at such a spinning station

A method for carrying out a piecing process on a spinning station of an air-jet spinning machine having an air-jet spinning device, wherein:

• taking up a thread end that has run onto a take-up bobbin by a thread take-up device and transferring the thread end to a thread-end preparation device downstream from a vortex chamber of the air-jet spinning device in a thread running direction;
• subsequently treating the thread end in the thread-end preparation device and then transferring the thread end to the vortex chamber of the air-jet spinning device and positioned there;
• powering up a drafting system for drafting and supplying a sliver to the vortex chamber, wherein an exit roller pair of the drafting system is accelerated up to a predetermined draw-off speed, and wherein the sliver is spun onto the thread end in the vortex chamber;
• and
• powering up a motor-driven draw-off device for drawing off thread spun in the vortex chamber and thereby accelerating up to a draw-off speed;
• wherein the drafting system and/or the draw-off device are powered up in such a way that a speed of the exit roller pair and/or of the draw-off device increases non-linearly at a beginning of powering up and/or approaches a predetermined draw-off speed non-linearly around an end of powering up;
• and
• wherein, in order to establish a period defining a dwell time of the thread end in the vortex chamber, the drafting system is powered up before the draw-off device.

A method for carrying out a piecing process on a spinning station of an air-jet spinning machine having an air-jet spinning device, wherein:

• taking up a thread end that has run onto a take-up bobbin by a thread take-up device and transferring the thread end to a thread-end preparation device downstream from a vortex chamber of the air-jet spinning device in a thread running direction;
• subsequently treating the thread end in the thread-end preparation device and then transferring the thread end to the vortex chamber of the air-jet spinning device and positioned there;
• powering up a drafting system for drafting and supplying a sliver to the vortex chamber, wherein an exit roller pair of the drafting system is accelerated up to a predetermined draw-off speed, and wherein the sliver is spun onto the thread end in the vortex chamber;
• and
• powering up a motor-driven draw-off device for drawing off thread spun in the vortex chamber and thereby accelerating up to a draw-off speed;
• wherein the drafting system and/or the draw-off device are powered up in such a way that a speed of the exit roller pair and/or of the draw-off device increases non-linearly at a beginning of powering up and/or approaches a predetermined draw-off speed non-linearly around an end of powering up;
• and
• wherein the exit roller pair is powered up in advance of and decoupled from at least one drafting system roller pair and/or apron roller pair of the drafting system arranged upstream from the exit roller pair in the thread running direction.

A method for carrying out a piecing process on a spinning station of an air-jet spinning machine having an air-jet spinning device, wherein:

• taking up a thread end that has run onto a take-up bobbin by a thread take-up device and transferring the thread end to a thread-end preparation device downstream from a vortex chamber of the air-jet spinning device in a thread running direction;
• subsequently treating the thread end in the thread-end preparation device and then transferring the thread end to the vortex chamber of the air-jet spinning device and positioned there;
• powering up a drafting system for drafting and supplying a sliver to the vortex chamber, wherein an exit roller pair of the drafting system is accelerated up to a predetermined draw-off speed, and wherein the sliver is spun onto the thread end in the vortex chamber;
• and
• powering up a motor-driven draw-off device for drawing off thread spun in the vortex chamber and thereby accelerating up to a draw-off speed;
• wherein the drafting system and/or the draw-off device are powered up in such a way that a speed of the exit roller pair and/or of the draw-off device increases non-linearly at a beginning of powering up and/or approaches a predetermined draw-off speed non-linearly around an end of powering up;
• and
• wherein during a take-up of the thread end that has run onto the take-up bobbin and the transfer of the thread end to the thread-end preparation device, and/or preparation of the thread end in the thread-end preparation device, and/or transfer and positioning of the thread end in the vortex chamber,
• the method includes operating the exit roller pair at a predetermined combing out speed, and stopping or operating at a holding speed associated with the combing out speed at least one drafting system roller pair and/or apron roller pair upstream from the exit roller pair in the thread running direction, the holding speed being a maximum of 10% of the combing out speed.

A method for carrying out a piecing process on a spinning station of an air-jet spinning machine having an air-jet spinning device, wherein:

• taking up a thread end that has run onto a take-up bobbin by a thread take-up device and transferring the thread end to a thread-end preparation device downstream from a vortex chamber of the air-jet spinning device in a thread running direction;
• subsequently treating the thread end in the thread-end preparation device and then transferring the thread end to the vortex chamber of the air-jet spinning device and positioned there;
• powering up a drafting system for drafting and supplying a sliver to the vortex chamber, wherein an exit roller pair of the drafting system is accelerated up to a predetermined draw-off speed, and wherein the sliver is spun onto the thread end in the vortex chamber;
• and
• powering up a motor-driven draw-off device for drawing off thread spun in the vortex chamber and thereby accelerating up to a draw-off speed;
• wherein the drafting system and/or the draw-off device are powered up in such a way that a speed of the exit roller pair and/or of the draw-off device increases non-linearly at a beginning of powering up and/or approaches a predetermined draw-off speed non-linearly around an end of powering up;
• and
• wherein the drafting system has a single-motor driven draw-off roller pair which can be controlled decoupled from additional drafting system roller pairs and/or apron roller pairs by a control unit.