Abstract: Apparatus and method for holding and feeding weft threads to the gripper of a weaving machine with drives, with which clamps for the weft threads are moved on motion paths into respectively a feed position, a transfer position and a ready position. The motion path of each clamp comprises a shape that is closed in itself. In that regard, the motion beginning of at least one of the clamps out of its ready position into its feed position takes place in a time segment that extends from the beginning of the beat-up motion of the weaving reed until the beat-up of the previously inserted weft thread against the beat-up line of the weaving machine.

Abstract: Apparatus and method for holding and feeding weft threads (1, 2) to the gripper (6) of a weaving machine with drives (25, 29), with which clamps (11, 12) for the weft threads (1, 2) are moved on motion paths (35, 36) into respectively a feed position (16, 19), a transfer position (17, 20) and a ready position (18, 21). The motion path (35, 36) of each clamp comprises a shape that is closed in itself. In that regard, the motion beginning of at least one of the clamps (11, 12) out of its ready position (18, 21) into its feed position (16, 19) takes place in a time segment that extends from the beginning of the beat-up motion of the weaving reed (9) until the beat-up of the previously inserted weft thread (1, 2) against the beat-up line (10) of the weaving machine.

Abstract: Method for measuring the fabric tension in a weaving machine, in which the fabric (1) is deflected by a deflecting shaft (2), wherein a bending force is applied onto the deflecting shaft (2) by the fabric (1). The flexure or bending displacement of the deflecting shaft (2) is measured by a sensor (3), which is arranged in an area between two supports (4.1, 4.2) of the deflecting shaft (2) on the weaving machine. The deflecting shaft (2) is connected with a machine frame (9) of the weaving machine via the two supports (4.1, 4.2). The spacing distance (A) between the two supports (4.1, 4.2) of the deflecting shaft (2) is reduced for larger fabric tensions to be measured and is increased for smaller fabric tensions to be measured. Furthermore, the invention relates to a corresponding weaving machine.

Abstract: Method for measuring the fabric tension in a weaving machine, in which the fabric (1) is deflected by a deflecting shaft (2), wherein a bending force is applied onto the deflecting shaft (2) by the fabric (1). The flexure or bending displacement of the deflecting shaft (2) is measured by a sensor (3), which is arranged in an area between two supports (4.1, 4.2) of the deflecting shaft (2) on the weaving machine. The deflecting shaft (2) is connected with a machine frame (9) of the weaving machine via the two supports (4.1, 4.2). The spacing distance (A) between the two supports (4.1, 4.2) of the deflecting shaft (2) is reduced for larger fabric tensions to be measured and is increased for smaller fabric tensions to be measured. Furthermore, the invention relates to a corresponding weaving machine.

Abstract: The invention relates to a method for applying forces and motions to warp threads (1, 1?) of a weaving machine with the following method steps: deflecting the warp threads (1, 1?) via a thread deflecting element (2) which is supported pivotably about a pivot axis (3); applying spring forces to the thread deflecting element (2) via more than three force application points (5) along a first line (6) which extends parallel to the pivot axis (3), wherein the spring forces are applied by at least one spring element (4); applying a prescribed positively constrained oscillating motion (38) onto the thread deflecting element (2) wherein this motion (38) is applied by a drive means (7) via a drive element (8), wherein the forces on the thread deflecting element (2) are supported partially via the thread deflecting element (2) on the at least one spring element (4) and partially via the drive element (8) on the drive means (7). The invention also relates to a corresponding apparatus.

Abstract: An apparatus for supplying compressed air to air-consuming components of an air-jet weaving machine includes plural pneumatically controllable pressure regulators (1.1, 1.2, 1.3), that each respectively have a pneumatic control inlet (3.1, 3.2, 3.3), plural electrically switchable valves (6.1, 6.2, 6.3) that are respectively connected to the pneumatic control inlets, an electrically controllable pressure regulator (4), and a control pressure line (5) that connects the outlet of the electrically controllable pressure regulator to the valves, and through the valves to the pneumatic control inlets of the pneumatically controllable pressure regulators.

Abstract: Air-jet weaving machine with an apparatus for the supply of compressed air with several pneumatically adjustable pressure regulators (1.1, 1.2, 1.3), wherein the pneumatically adjustable pressure regulators (1.1, 1.2, 1.3) respectively comprise a pneumatic control inlet (3.1, 3.2, 3.3). Furthermore an electrically controllable pressure adjusting means (4) and a control pressure line (5) is present, in which various different air pressure values are producible by the electrically controllable pressure adjusting means (4). To each pneumatic control inlet (3.1, 3.2, 3.3), an electrically switchable valve (6.1, 6.2, 6.3) is allocated, by which the pneumatic control inlet (3.1, 3.2, 3.3) is connectable with the control pressure line (5).

Abstract: A gripper head for the insertion of weft threads on a gripper weaving machine as well as a gripper weaving machine with such a gripper head. The gripper head thread clamp for the weft thread is controlled in a contact-free manner and with high transfer reliability of the weft thread even in the machine center.

Abstract: A thread clamp (3, 103, 203), which comprises a stationary clamping part (4, 104, 204) and a movable clamping part (5, 105, 205), is mounted on a gripper head (1, 101, 201) for the insertion of weft threads (2) on a gripper weaving machine. For opening or closing the thread clamp (3, 103, 203), it is connected with a hollow body (6, 106, 206) that is expandable by pressurized air. A second expandable hollow body (8, 108, 208) is pressed together in such a manner so that an internal pressure builds up therein, by means of a control arrangement mounted on the gripper weaving machine. Moreover, a valve (9, 109, 209) is present on the gripper head, which valve is embodied as an automatically closing non-return or check valve. The valve (9, 109, 209) is opened by an increase of the internal pressure in the second expandable hollow body (8, 108, 208) or by contact-free transmission of signals or forces of an actuator (13, 113, 213) mounted on the gripper weaving machine.

Abstract: A method and a clamping device for clamping a weft thread in a jet weaving machine are proposed. The weft thread strand runs through the beginning section (2.1) and the end section (2.2) of a mixing tube. The two sections between themselves form an engagement opening (8) and are connected with a first holding magnet (11) by a counter support (9). An actuator (6) in the form of an elastomeric bellows, which comprises a chamber (10), is located on the beginning section (2.1) of the mixing tube. The chamber (10) is connected to a valve (16) via a supply line (20) and is acted on variably with compressed air. By deformation of the actuator (6), a clamping element (7) connected thereto carries out a tilting movement between the counter support (9) and a contact stop part (19), which contains a second holding magnet (12). The holding magnets (11, 12) lead to an exact and reliable clamping of the weft thread (3).

Abstract: A method and a clamping device for clamping a weft thread in a jet weaving machine are proposed. The weft thread wire or strand runs through the beginning section (2.1) and the end section (2.2) of a mixing tube. The two sections between themselves form an engagement opening (8) and are connected with a first holding magnet (11) by a counter support (9). An actuator (6) in the form of an elastomeric bellows, which comprises a chamber (10), is located on the beginning section (2.1) of the mixing tube. The chamber (10) is connected to a valve (16) via a supply line (20) and is acted on variably with compressed air. By deformation of the actuator (6), a clamping element (7) connected thereto carries out a tilting movement between the counter support (9) and a contact stop part (19), which contains a second holding magnet (12). The holding magnets (11, 12) lead to an exact and reliable clamping of the weft thread (3).

Abstract: A thread clamping device is provided for a jet weaving machine that has a main discharge nozzle (1) with a mixing tube (2) for inserting a weft thread (3) into a shed with a conveying fluid discharged from the main discharge nozzle. This clamping device is placed inside the mixing tube (2) in the area from which the weft thread exits, and has an actuator, which is situated outside of the mixing tube (2), and a lever connected to the actuator so that this lever is actuated by the actuator (6) to execute a tilting or pivoting motion whereby the weft thread is clamped between the lever and an abutment (9) in an opening of the mixing tube.

Abstract: The invention relates to a jet-weaving machine, particularly an air jet-weaving machine, which comprises a main discharge nozzle (1) with a mixing tube (2) for introducing a weft thread (3) into a shed by means of a conveying fluid discharged from the main discharge nozzle (1), and comprises a clamping device. This clamping device is placed inside the mixing tube (2) in the area from which the weft thread exits, and is provided with an actuator, which is situated outside of the mixing tube (2) and with a lever that is connected thereto in such a manner that this lever, when actuating the actuator (6) via an actuating means or when the actuation is stopped, executes a tilting motion whereby clamping the weft thread in an opening of the mixing tube between itself and an abutment (9).

Abstract: An arrangement for supplying air with a controlled pressure to the main weft insertion nozzles of an air jet loom includes a single servovalve connected between a pressurized air source, an air vent, and a pressure manifold, and individual shut-off valves respectively interposed in branch lines connected from the pressure manifold to the individual nozzles. A pressure sensor measures the actual pressure provided to the manifold. An electronic controller receives a pressure control signal and controls the servovalve responsive to any difference between the pressure control signal and the actual measured pressure signal. The arrangement is simple, economical, and rapidly reacting, to avoid the need of individual throttle valves or pressure regulators for the individual nozzles.

Abstract: An arrangement for supplying air with a controlled pressure to the main weft insertion nozzles of an air jet loom includes a single servovalve connected between a pressurized air source, an air vent, and a pressure manifold, and individual shut-off valves respectively interposed in branch lines connected from the pressure manifold to the individual nozzles. A pressure sensor measures the actual pressure provided to the manifold. An electronic controller receives a pressure control signal and controls the servovalve responsive to any difference between the pressure control signal and the actual measured pressure signal. The arrangement is simple, economical, and rapidly reacting, to avoid the need of individual throttle valves or pressure regulators for the individual nozzles.

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.

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.

Abstract: The warp tension is measured in a weaving loom by measuring the fabric tension downstream of the beat-up point. For this purpose a measuring device is arranged in a suitable position downstream of the beat-up point. Such an arrangement is possible because the fabric tension in the take-up direction is directly proportional to the warp tension. The measuring device includes a measuring beam supported, for example, in the spreader bar or pipe. The measuring beam is in contact with the fabric and cooperates with sensor elements such as foil strain gages, pressure gages, or other suitable sensors or pick-ups such as displacement pick-ups. This type of arrangement has the advantage that the warp thread tension can be measured with high precision due to the mentioned proportionality and independently of temperature influences. Additionally, impairment of, or damage to the warp threads is avoided by measuring downstream of the beat-up point.