Method and device for regulating a back rest and/or a drop wire position of a weaving machine

A method for adjusting a position of at least a backrest which is arranged in a spring-loaded and adjustably supported manner and/or a warp stop motion which is adjustably supported on the machine frame of a loom that is further equipped with a loaded warp beam, wherein both the backrest and the warp stop motion are movable from an actual position into a respective prescribed desired position by allocated adjusting means with at least one adjusting function, wherein the method comprises the following steps:

• a) permanently allocating at least one controllable driven adjusting device to the adjusting means,
• b) storing the prescribed desired position of the backrest and/or of the warp stop motion as a desired value in a control unit by means of the adjusting means,
• c) recognizing the respective adjusting function of the adjusting means,
• d) determining the existing actual position of the backrest and/or of the warp stop motion,
• e) weaving the warp off from the warp beam, and automatically and continuously comparing the actual position with the prescribed desired position in the control unit during the weaving-off of the warp from the warp beam,
• f) responsive to and dependent on the comparing, generating an adjusting signal that is required at least for moving the backrest for maintaining the geometry of the back shed constant, and providing the adjusting signal to the adjusting device, and
• g) operating the adjusting device based on the adjusting signal to correspondingly operate the adjusting means to the extent necessary for adjusting at least the backrest to the desired position.

An apparatus for adjusting a position of at least a backrest and/or a warp stop motion that are tiltably supported on the machine frame of a loom equipped with a loaded warp beam, the apparatus comprising:

• adjusting means allocated to the backrest (3) and/or the warp stop motion (17) with at least one adjusting function for adjusting the position of the backrest and/or the warp stop motion in at least one adjustment direction,
• operating means (25, 26) of the adjusting means allocated to the at least one adjusting function,
• an adjusting device (30) for acting on the operating means of the adjusting means, which includes drive means for driving the operating means,
• means (33, 34) for recognizing the adjusting function of the respective operating means,
• means (35, 36, 47) for determining the respective existing actual position of the backrest (3) and/or of the warp stop motion (17), and
• a control unit (38) which is connected with the adjusting device and with the means for recognizing the adjusting function and the means for determining the position of the backrest and/or the warp stop motion, and which carries out a comparison of desired position data that are valid for the recognized adjusting function with data that are characteristic of the recognized adjusting function and of the determined actual position and that are received by the respective means, and which generates an adjusting signal responsive to and dependent on the comparison, and which delivers the adjusting signal to the adjusting device (30) for moving the backrest (3) and/or the warp stop motion (17) into a respective desired position identified by the desired position data.