Method and apparatus for the insertion of a weft thread in a weaving machine

A method for the insertion of a weft thread (2) into a shed of an air jet weaving machine (1) having a thread store (21), at least one acceleration nozzle (3, 4) and a plurality of auxiliary nozzles (5.1 a-c to 5.n a-c), in which method

• the weft thread (2) drawn from the thread store (21) is accelerated by means of an acceleration nozzle (3, 4) and supplied to the shed;
• the weft thread is transported further in the shed by means of the auxiliary nozzles (5.1 a-c to 5.n a-c);
• measured values dependent on the speed of the weft thread and/or on the path traveled by the weft thread are measured in contact-free manner by means of one or more measurement pickups (7.1, 7.2, 17)
• characterized in that
• at least one of the measurement pickups, which will be termed a special measurement pickup (6, 6.1-6.5) in the following, is formed for multiple or continuous measurement within the weft insertion and is arranged after a thread centering device (23) provided at the outlet of the thread store (21), or after the latter or at or after a thread brake (9) provided separate from the thread store (21), or at or after a first acceleration nozzle (3) following the thread store;
• during the weft insertion measured values are measured in contact-free manner a plurality of times or continuously by means of the at least one special measurement pickup (6, 6.1-6.5) from which values for the speed of the weft thread and/or the path traveled by the weft thread (2) and/or for a parameter linked to the speed of the weft thread and/or to the path traveled by the weft thread are determined during the weft insertion;
• and
• the values determined during the weft insertion are used for the regulation and/or control of the weft insertion and in particular for the current weft insertion.