Patent Application
20090288730
The invention relates to a loom, in particular a ribbon loom.
Looms, in particular ribbon looms of the type initially mentioned, are commonly known. Usually, the thread quantity to be transported for warp threads and/or weft threads in looms is supplied to the processing station either under negative control, to be precise tension control, or positively with a fixed mechanical setting. The disadvantage of a negative thread control is that the threads are subjected to load, particularly when threads of different quality and properties are used. In the case of rubber threads or other threads with elasticity, the negative control has to be adapted in each case, since the threads would otherwise be loaded by harmful stresses. By contrast, in the case of a positive mechanical control with a fixed setting, there is a disadvantage that the thread feeders can operate only with an adjustable constant pull which can be set only in terms of the weakest thread, with the result that the quality of the woven cloth is impaired.
EP 1 526 199 A discloses a loom with individually drivable thread transport devices which can be activated individually according to the pattern program, but control takes place as a function of tension, and individual overriding adaptation is not provided.
WO 2004/111322 discloses, for knitting machines, a mechanism with an electronic control device for controlling the weft thread introduction, which, on the basis of a pattern program regulates an individual thread transport for the knitted cloth to be produced. The knitting machine contains, furthermore, a correcting apparatus, by means of which an adjustable correcting factor can be superposed on the pattern-compatible functioning of components of the knitting machine.
WO-A-88/05089 discloses a method for regulating the warp thread tension in looms by regulating the drive speed of the warp beam and/or of the cloth beam by means of program-controlled stepping motors. However, a regulation of the weft thread tension or quantity is not disclosed, provided or suggested there. A similar method and a corresponding device for releasing and regulating the warp thread quantity is known from WO-A-91/05895, said warp thread quantity being calculated by means of a control arrangement, for example with a keyboard. However, here, too, a regulation of the weft thread tension or quantity is not disclosed, provided or suggested.
The purpose of the invention is to improve further a loom of the type initially mentioned.
Since in a loom, in particular in a ribbon loom, with at least one electrically driven thread transport device for at least one weft thread, with a cloth take-up for the woven cloth and with an electronic control device for controlling the loom on the basis of a pattern program for the woven cloth to be produced, there is provision for the control device to have control means in order automatically to set, at the at least one thread transport device, the delivery length of the weft thread to be supplied, this ensures, in the first place, that the exact thread length required is always available for each weft thread insertion and each pattern. There is no longer any need for taking up the weft thread, for example from a cone, by means of a weft insertion device. As a result, the woven cloth, in general, and pattern formation, in particular, are improved substantially. During the weaving operation, faults, such as thread breaks and defects, are largely prevented. Since the delivery length can be calculated not only using data from the pattern program and from the cloth take-up, but, in particular, also from data relating to the width, varying greatly during the weaving operation, of the woven cloth to be produced, the result of the measures of the invention is, moreover, that such changes can be reacted to during the weaving operation.
It is advantageous in this case if the loom has an electrically driven further thread transport device for the warp threads. The control device in this case also has control means in order automatically to set at the thread transport device the delivery length of the warp threads to be supplied, according to the data predetermined in the pattern program. The delivery length of the further thread transport device for the warp threads can likewise be calculated, using data from the pattern program, the cloth take-up and the width of the woven cloth to be produced.
A particularly advantageous development is that by means of the correcting factor KS which additionally varies the pattern-compatible functioning data at least of the weft thread supply, further individual adaptation, for example, to different thread qualities and/or pattern properties of the woven cloth to be produced can be achieved. Such a correcting factor KK or KW is preferably also provided for the cloth take-up and/or the warp thread supply.
A particularly advantageous correcting apparatus has a display screen, preferably a touch screen, and also an editing element for the manual selection of various indicator and control planes, in particular that for handling the correcting factor or correcting factors.
A version of the loom is advantageous when the control of the thread transport device is designed as an integrated constituent of the machine control.
For a loom with weft threads of various types, in particular for weft threads of different color, it is advantageous if at least two electrically driven thread transport devices for weft threads are provided and the control means are designed correspondingly. In this case, it is advantageous if correcting factors different for the weft threads are provided for the thread transport devices, particularly when the weft threads of different type are supplied by these thread transport devices.
Exemplary embodiments of the invention are described in more detail below by means of the drawings in which:
The woven cloth 14 produced is taken up by means of a cloth take-up 16 and rolled up into a cloth roll 18.
The warp threads are supplied to the weaving station 2 by one or more warping frames 20, 20a, 20b, 20c. At least a number of warping frames are assigned in each case an individually controllable thread transport device 22a, 22b, 22c. At the weaving station 2, further, one or more weft threads 10 can be supplied in succession, which are in each case taken up in an individually controllable way by thread bobbins 24a, 24b by means of controllable thread transport devices 26a, 26b.
The loom is equipped with a control device 36 which controls the components of the loom on the basis of a pattern program. Such a pattern program may be produced either on the loom itself or on an external pattern apparatus 38, from which the pattern program is read into a reader 42 of the control device 36, for example via lines or via a floppy disk 40. The control device 36 contains control means in order to set the delivery length of the warp threads 4 to be supplied and/or of the weft threads 10 according to the cloth pattern predetermined from the pattern program. Furthermore, the control device 36 has a manual actuable correcting apparatus for individually superposing an adjustable correcting factor KS or KK, which may be plus or minus, upon the delivery date of at least one weft thread 10 and of at least one warp thread 4 for at least one weft insertion. The correcting apparatus is described in more detail with reference to
The correcting apparatus contains a display screen 44 which is preferably designed as a touch screen and which has a row of indicator and switching elements for manually selectable indicator and switching planes. In a first switching field 46, any desired thread transport device 22a, 22b, 22c, 26a, 26b can be selected by means of selector keys 48a, 48b and then appears in the indicator field 50. In a second switching field 52, the correcting factor KS or KK can then likewise be set by means of selector keys 54a, 54b to a desired value which appears in the indicator field 55. In a third switching field 56, finally, it is possible to set the weft or weft region for which the correcting factor KS or KK is set in each case is to be applicable. By means of selector keys 58a, 58b, the number of the weft x1 to xn can be set, the said values then being indicated on the indicator fields 60a, 60b. An actuating key X serves for changing the indicator field or for generally resetting the settings, so that the control device controls the components solely according to the pattern program entered. In the example shown, a correcting factor KS=102% is set on the correcting apparatus for the thread transport device number 26a and means that the already individual normal delivery length, which is predetermined by the control means on the basis of the pattern program and amounts to 100%, is to be increased by 2%. This value will then apply to the wefts x1 and x2 or x1 to x2.
By means of the correcting apparatus, a correcting factor KW can be superposed not only on the normal delivery quantity of the weft threads, but, alternatively or additionally, also on the delivery quantity of one or more warp threads and/or on the speed of the cloth take-up. The correcting factors KS, KW, KK may be identical for various components, but they are preferably different. Particularly for the thread transport devices 26a, 26b, illustrated in the exemplary embodiment, for the weft threads, a different correcting factor KS may have to be provided when weft threads of different type are supplied by these thread transport devices 26a and 26b. The same also basically applies in a similar way to the correcting factors KK for the thread transport devices 22a, 22b, 22c for the warp threads.
| Number | Date | Country | Kind |
|---|---|---|---|
| 720/06 | May 2006 | CH | national |
This application claims priority of PCT application PCT/CH2007/000192 having a priority date of May 4, 2006, the disclosure of which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CH2007/000192 | 4/20/2007 | WO | 00 | 10/14/2008 |
