US 6,439,271 B2Granted

Jet loom and method for achieving substantially identical weaving cycle times

AssigneeLindauer Dornier Gesellschaft mbH

InventorsPeter Schiller, Dieter Teufel, Markus Gielen

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Abstract

A valve arrangement of a loom includes valve modules held between flange plates and sharing a common inlet feeding into a common inner valve space. A valve outlet of each valve module leads to an insertion nozzle or nozzle group, and is controlled by a valve disk actuated by a piezoelectric actuator to rapidly dynamically adjust the pressure profile. A quality parameter, characteristic of the thread insertion flight time of each weft thread, is stored in a data bank and has a nominal pressure profile for achieving a nominal thread flight time allocated thereto. The actual thread flight time of each weft thread is measured and compared with the stored nominal thread flight time. A control signal responsive to the time difference is provided to the valve arrangement to control the piezoelectric actuator so as to adjust the pressure and/or the quantity of the pressure medium provided through the valve module to the connected insertion nozzle. Alternatively, the control signal is provided to the main loom rotational drive to adjust the rotational speed of the loom.

A method of operating a jet loom to achieve substantially identical weft thread flight times of successive weft threads being inserted into successive loom sheds in successive weaving cycles regardless of respective thread quality parameters of said successive weft threads, comprising the following steps:

a) prescribing a nominal weft thread flight time in which a weft thread is to be inserted into a loom shed during a weaving cycle;
b) prescribing an initial nominal pressure profile of a pressurized fluid to be supplied over time to a weft insertion nozzle during said weaving cycle for inserting said weft thread, wherein said initial nominal pressure profile is allocated to and based on is a thread quality parameter of said weft thread that is characteristically related to achieving said nominal weft thread flight time;
c) providing said pressurized fluid to said weft insertion nozzle through a piezoelectrically actuated valve arrangement according to said initial nominal pressure profile, so as to insert said weft thread;
d) measuring an actual weft thread flight time of said weft thread inserted during said step c) in a single present one of said weaving cycles that is being carried out;
e) comparing said actual weft thread flight time with said nominal weft thread flight time;
f) if said comparing in said step e) determines a substantial difference between said actual weft thread flight time and said nominal weft thread flight time, then generating a control signal responsive to and dependent on said difference;
g) performing one of the following sub-steps:
g1) sensing and measuring an actual pressure profile of said pressurized fluid provided through said valve arrangement to said weft insertion nozzle, and providing said control signal to said valve arrangement so as to actuate said valve arrangement so that said actual pressure profile deviates from said initial nominal pressure profile, for inserting a next successive weft thread in a next successive weaving cycle;
or
g2) providing said control signal to a main loom rotational drive so as to adjust a rotational speed of said main loom rotational drive;
and
h) repeating said steps d) to g) in successive weaving cycles so as to minimize said difference between said actual weft thread flight time and said nominal weft thread flight time.

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Abstract

Claims26