WO2003008684A1

WO2003008684A1 - Weaving machine

Info

Publication number: WO2003008684A1
Application number: PCT/NL2002/000437
Authority: WO
Inventors: Gijsbertus De Swart
Original assignee: Te Strake Textile B.V.
Priority date: 2001-07-20
Filing date: 2002-07-04
Publication date: 2003-01-30
Also published as: CN1329576C; DE60220919D1; DE60220919T2; EP1409778B1; EP1409778A1; CN1527893A; JP2004536238A; ATE365824T1; NL1018600C2

Abstract

A weaving device fitted with a yarn preparing device (2) comprising a yarn feeding drum (3), on which yarn (5) being supplied from a supply spool (1) is stored temporarily before being passed on to a yarn processing device (4), in which the device comprises a stop element (7) which is movable relative to the drum surface, which stop element (7) can block the unwinding of the yarn (5) at desired moments, in which the device furthermore comprises means for measuring the force in the yarn at least during one or more sub-intervals of the weft insertion process, which means transfer the obtained values to an evaluation device (15), which at least transfers said values to a display device (17), wherein the stop element (7) and possibly also the movable braking element (6) includes force measuring means, which measure the force being exerted on the aforesaid elements by the yarn (5) and which transfer the measured data to the evaluation device (15) and to the display device (17).

Description

DESCRIPTION

EA ING MACHINE

The present invention relates to a weaving device fitted with a yarn preparing device comprising a yarn feeding drum, on which yarn being supplied from a supply spool is stored temporarily before being passed on to a yarn processing device, in which the device comprises a stop element which is movable relative to the drum surface, which stop element can block the unwinding of the yarn at desired moments, and in which the device furthermore comprises means for measuring the force in the yarn at least during one or more sub-intervals of the weft insertion process, which means transfer the obtained values to an evaluation device, which at least transfers said values to a display device. Weaving devices of the kind described above are known, for example from International patent application no. WO 00/56964.

In said known device, the weft yarn is passed through a braking device after leaving the feeding drum and subsequently through a tension measuring device, which continuously measures the yarn tension and which transfers the measured values to an evaluation device, which in turn transfers the signal to a display device, on which the development of the yarn tension during the weft insertion process is visualised, so that the user can take note thereof and possibly adjust parameters on the basis thereof. In order to achieve this, the known device makes use of an additional element, viz. the tension measuring device, which involves additional cost, of course, as well as additional friction and yarn wear, and which thus has an adverse effect on the weaving process.

The object of the present invention is to provide a device of the same kind, in which it is not necessary to fit the device with an additional element in order to obtain information on the yarn tension. The invention is based on the idea that in order to obtain a proper insight into the development of the yarn tension during the weft insertion process it actually suffices to know the yarn tension and visualise it for certain critical intervals of the weft insertion process. Said critical points are generally the starting phase, the braking phase, the stop phase and the cutting phase.

In order to accomplish that objective, the weaving device according to the present invention is characterized in that the stop element includes first force measuring means, which measure the force being exerted on the stop element by the yarn during those intervals of the weft insertion process that the yarn is in contact with the stop element, and which transfer the measured data to the evaluation device.

In this way, information on the yarn tension is obtained at intervals which are critical for the weft insertion process, viz. the starting phase, the stop phase and the cutting phase, wherein use is made of an element which is already present in the device for another function. In order to be able to measure the forces exerted by the yarn, the stop element is fitted with pressure sensors, for example, which measure the forces that are being exerted and which transfer the measured values to the evaluation device.

In order to obtain information about the yarn tension during the braking phase as well, another embodiment of the device according to the invention furthermore comprises a yarn braking device disposed between the yarn preparing device and the yarn processing device, which yarn braking device comprises second force measuring means for measuring the yarn tension during the interval of the weft insertion process that the yarn is in contact with the movable braking element, in which said means deliver the measured signals at least to the aforesaid evaluation device, which in turn passes on said signals to the display device.

In this way the user obtains a good insight into the development of the yarn tension during the aforesaid critical intervals of the weft process.

According to another embodiment of the weaving device according to the invention, said evaluation device is also in communication with the control processor of the weaving device, which enables the control processor to carry out certain control activities on the basis of signals received from the evaluation device.

The invention will be explained in more detail hereinafter with reference to the accompanying drawing, which shows an embodiment of a weaving device according to the invention.

Figure 1 schematically shows an arrangement of a weaving device;

Figure 2 schematically shows the development of the yarn tension during the weft process; Figure 3 is a schematic, sectional view of the stop element as used in the weaving device that is shown in Figure 1;

Figure 4 schematically shows an insertion brake such as the one that may be used in the weaving device that is shown in Figure 1.

In Figure 1, numeral 1 indicates a yarn spool. A yarn 5 extends from said spool to a yarn preparing device 2 comprising a drum 3 on which the yarn is stored in a number of windings, from which drum the yarn is fed to a yarn processing device in the form of a loom 4. The yarn

5 furthermore passes through an insertion brake 6 disposed between the yarn feeding drum 3 and the loom 4. Disposed opposite the circumferential surface of the yarn feeding drum 3 is a stop element 7 which may be configured as shown in

Figure 3. As is shown in the figure, the stop element is built up of a housing 8 containing an electric coil 9, which may be connected to a voltage source (not shown) and which co-acts with an anchor 10 which can move upwards and downwards under the influence of the forces exerted by the coil 9 and which, in the position in which it has been moved towards the drum, prevents the yarn 5 being unwound from the feeding drum 3. The anchor 10 is provided with a stop pin 11, which, as already said before, can be moved towards the drum. The stop pin 11 is guided in a bearing 12, which is fitted with a pressure sensor 13, by means of which the force being exerted on the stop pin 11 by the yarn 5 can be measured. The signal from the pressure sensor 13 is transferred, via a line 14, to an evaluation device 15, which in turn transfers the signal to a display panel 17 via a line 16.

As is shown in more detail in Figure 4b, the brake 6, which functions to decelerate the yarn 5 during a certain period of the weft insertion process, is provided with a movable braking element 18, which, as is shown in more detail in Figure 4b, may be a lever, for example, which is mounted on the shaft of an electric motor 19 which is capable of moving the arm 18 to different positions so as to obtain different braking effects, in which the force exerted by the motor is a measure of the yarn force. By measuring the current supplied to the motor and the position of the movable element, a measure of the force which the lever 18 exerts on the yarn 5 can be obtained, and thus a measure of the tension in the yarn. The value of said tension is likewise supplied, via the line 30, to the evaluation device 15, which in turn transfers said value, via the line 16, to the display panel 17 on which said tension can subsequently be visualised.

During the weaving process, a number of phases occur, which phases are shown in succession in Figure 2. During the starting phase I, the yarn 5 is still in contact with the stop element 7, and the tension being exerted on the stop element by the yarn 5 is displayed on the display panel as an ascending line 31 during this phase. After the starting phase I, in which a particular yarn tension is realised by the main injector, a period follows in which the yarn is passed through the loom 4 at a nearly constant velocity, after which a braking phase II begins at the moment when the yarn 5 has nearly reached the end of the shed, at which point the brake 6 comes into operation and a braking force is exerted on the yarn 5 by the braking element 18 and, as a reaction thereto, a yarn force is exerted on the braking element 18. Said yarn force is measured by the brake 18, with the measured value being transferred to the evaluation device 14, which subsequently visualises it on the display panel 17 in the form of a peak 32 which represents the development in the tension during the braking phase II. At the end of the braking phase, the stop phase III begins, in which the stop element 11 is pressed against the drum surface 3, so that further unwinding of the yarn is prevented and the yarn exerts a yarn force on the stop element 11, which yarn force is measured by the pressure sensor 13, with the measured value being transferred to the evaluation device 15, which displays said yarn force as a line 33 on the display panel 17. At the end of the stop phase III, the yarn is cut and a cutting phase IV occurs, in which the yarn 5 is still in contact with the stop element 11, which measures the tension in the yarn at that moment and transfers the measured value from to the evaluation device 15, which again displays said tension as a line 34 on the display panel 17 during said phase. In this way, a good image of the yarn tension is obtained, at any rate for the critical phases I, II, III and IV, as is shown in Figure 2. The user can thus take note of the development of the tension in the yarn during said critical phases at all times. The user may change the device adjustments on the basis of the obtained information. The changing of the device adjustments may also take place automatically, in that the evaluation device 15, communicates with the control processor 42 of the loom and/or the weaving device via the lines 40 and 41.

According to the invention it is thus possible in the above-described manner to gather information about the yarn tension during critical phases of the weft insertion process by means of elements that are already present in a weaving device.

Claims

1. A weaving device fitted with a yarn preparing device comprising a yarn feeding drum, on which yarn being supplied from a supply spool is stored temporarily before being passed on to a yarn processing device, in which the device comprises a stop element which is movable relative to the drum surface, which stop element can block the unwinding of the yarn at desired moments, and in which the device furthermore comprises means for measuring the force in the yarn at least during one or more sub-intervals of the weft insertion process, which means transfer the obtained values to an evaluation device, which at least transfers said values to a display device, characterized in that the stop element includes first force measuring means, which measure the force being exerted on the stop element by the yarn during the intervals of the weft insertion process that the yarn is in contact with the stop element, and which transfer the measured data to an evaluation device, which at least passes on said signals to the display device.

2. A weaving device according to claim 1, further comprising a yarn insertion brake disposed between the yarn preparing device and the yarn processing device, through which the yarn is passed, characterized in that the yarn braking device comprises second force measuring means for measuring the yarn tension during the interval of the weft insertion process that the yarn is in contact with the brake, which means deliver a corresponding signal at least to the aforesaid evaluation device, which passes on said signals to the display device.

3. A weaving device according to claim 1 or 2, characterized in that said evaluation device also receives signals from and transfers signals to a control processor of the weaving device.