Thread-feed device for textile machines and method of operation

A thread-feed device for textile machines having a stationary winder drum onto which a thread fed from a stationary winding bobbin can be wound by means of a rotatable winder arm for the formation of a thread supply and the thread supply formed can be withdrawn on top, and having a first detection device for automatically controlling the rotary movement of the winder arm as a function of the length of the supply of thread formed, characterized by:

• a. a second detection device arranged in the region of the withdrawal end of the winder drum to give a first signal upon each passage of the thread during its withdrawal through its monitoring region,
• b. a control unit arranged behind the second detection device for the counting of the first signals and the giving off of a second signal as soon as the number of first signals reaches a predetermined adjustable value corresponding to the required length of thread,
• c. a thread gripper means which is operably connected to the control unit and can be controlled by the second signal, the thread gripper means arranged fixed in space in the region of the withdrawal end of the winder drum and having an electromagnetically actuatable bolt which is movable against the cylindrical surface of the winder drum and in its active position forms a stop for the filling thread withdrawn, the said thread gripper means being arranged outside the winder drum and the winder drum is provided on its circumference with a recess for the entrance of the end of the bolt into the wall of the winder drum.

A method of operating a thread-feed device for textile machines having a stationry winder drum onto which a thread fed from a stationary winding bobbin can be wound by means of a rotatable winder arm for the formation of a thread supply and the thread supply formed can be withdrawn on top, and having a first detection device for automatically controlling the rotary movement of the winder arm as a function of the length of the supply of thread formed, characterized by:

• a. a second detection device arranged in the region of the withdrawal end of the winder drum to give a first signal upon each passage of the thread during its withdrawal through its monitoring region,
• b. a control unit arranged behind the second detection device for the counting of the first signals and the giving off of a second signal as soon as the number of first signals reaches a predetermined adjustable value corresponding to the required length of thread, and
• c. a thread gripper means which is operably connected to the control unit and can be controlled by the second signal;
• said device being operated to determine how many thread turns on the winder drum correspond to the length of thread required for a filling insertion on a loom by adjusting the first detection device for the control of the rotary movement of the winder arm to a number which is greater than the required number n of the turns, and so adjusting the control unit that upon the arrival of the (n-1)th first signal it gives off a second signal so that the thread gripper means is activated between the (n-1)th and the nth pass of the thread.