Method for correcting a weft fault on weaving machines, especially air-jet weaving machines with automatic selvedge tucking devices
AssigneeLindauer Dornier Gesellschaft mbH
InventorsHubertus Ludwig, Hans-Joachim Zeller, Adnan Wahhoud
Life of this patent
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Abstract
A method and a machine to assist the automatic correction of a weft fault in the manufacture of fabric with pneumatically created insertion edges. During the automatic correction of a weft fault, at least one additional air blast from a nozzle drives the weft thread contrary to the weft thread beating-up movement of a reed.
Claims15
Method for correcting a weft fault on an air-jet weaving machine having a pneumatic selvedge tucking device disposed at entry and exit ends of a shed, comprising:
- blowing a weft thread by a main nozzle into a weft thread input channel of a reed and using a weft thread monitor to detect the weft thread as a weft fault present at an exit end of the reed,
- holding an end of the weft thread by a suction nozzle disposed at the exit end of the weft thread monitor,
- preventing cutting of the weft thread between the main jet nozzle and the selvedge tucking device at the entry end,
- beating the weft thread by the reed against the edge of a fabric and binding in the same in by warp threads,
- undoing a previously performed tying in of the weft thread,
- releasing the weft thread from the edge of the fabric with formation of a weft thread loop and drawing the same out of the shed by the suction of the suction nozzle, and
- providing at least one additional air blast to drive the weft thread approximately against the weft thread beating movement of the reed during or after the release of the weft thread from the edge of the fabric.
An air-jet weaving machine, comprising:
- at least two heald frames forming a shed;
- a main jet nozzle;
- a plurality of relay jets;
- a reed to beat weft threads against an edge of a fabric;
- a weft thread insertion channel;
- at least one weft thread monitor present at an exit end of the weft thread insertion channel;
- a stationary suction nozzle disposed at an exit end of the weft thread monitor;
- an entry-end pneumatic selvedge tucking device proximate an entry end of the shed;
- an exit-end pneumatic selvedge tucking device proximate an exit end of the shed;
- an entry-end weft thread shear;
- an exit-end weft thread shear;
- and
- an air jet nozzle having a discharge end aimed at a section of the weft thread lying between the exit end of the shed and an opening of the exit-end pneumatic selvedge tucking device on the shed side for discharging at least one air blast against the section of the weft thread.
Method for correcting a weft fault in an air-jet weaving machine having a reed which beats weft threads against an edge of a fabric, and having a pneumatic selvedge tucking device disposed at an exit end of a shed, wherein when a weft fault is detected a faulty weft thread is released from the edge of the fabric and is drawn out of the shed by a suction nozzle, said method comprising:
- during or after the release of the weft thread from the edge of the fabric, discharging at least one additional air blast against the faulty weft thread in a direction approximately against the weft thread beating movement of the reed.
An air-jet weaving machine, comprising:
- a shed having an entry end and an exit end;
- a reed to beat weft threads against an edge of a fabric;
- at least one weft thread monitor which detects a weft fault;
- a suction nozzle which removes a faulty weft thread;
- a pneumatic selvedge tucking device proximate the exit end of the shed;
- and
- an air jet nozzle having a discharge end aimed toward the pneumatic selvedge tucking device in a direction approximately against the weft thread beating movement of the reed.
Dependencies are inferred from the claim text.