SU1285087A1 - Device for monitoring weft density in fabric - Google Patents

Abstract

The invention makes it possible to control the density of the weft fabric (the number of strands per unit length) on any type of loom. Screen 1 moves synchronously with the fabric (the screen is attached to the fabric in some way or another). The measurement zone is defined by the distance between point photo cells 4 and 5. When screen 1 overlaps the light (from a distributed source 2) entering the photo cell 4, the control process begins. A characteristic feature of the work of weaving machines is the reciprocating movement of the fabric for each weft yarn. As a result, the screen 1 beams of light from source 2, acting on the linear photocell 3, at the output of the latter, voltage surges take place, which are recorded by the counter 8. The number of these jumps at a given length and is a measure of the density of the tissue. The control process ends when a photocell is triggered. 5. 1 Il. Mr. J (L with

Description

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The invention relates to textile industry, more specifically to devices for controlling the density of the duck directly on the machine. 5

The purpose of the invention is to increase the control accuracy by eliminating errors from the reciprocating movement of the tissue.

The drawing shows a block diagram of the device Yu.

The device contains an optoelectronic unit for checking the presence of weft yarns and fabric length, consisting of strip 1 (flat screen), made from an opaque material, a distributed light source 2, a linear photodetector 3 and two accurate photoreceivers A and 5, which are located along The edges of the linear 20 photodetector 3. The source 2 and the photodetector 3 are mounted opposite one another and parallel to the direction of motion of the fabric. Length L, flag.} Not less than the length L of the photodetector 3.

The output of the photodetector 4 through the element NOT 6 is connected with one input of the element I 7, the other input of which is connected to the output of the photocell 5. The control input of the binary-decimal counter 8 is connected with the output of the element 7 and its output through the encoder 9 is connected to the input of the digital indicator 10. The output of the photocell 3 through the amplifier 1G and the driver 12 of the counting 35 pulses is connected with the sum of the input of the counter 8. The elements 6-12 form the recorder 13.

The device works as follows .40

The holder (not shown) of the control unit is fixed on the bed of the loom (not shown) in such a way that the control unit is positioned above 45 cloth and the flag 1 pre-fixed on the cloth is lowered into its cross section between the distribution source 2 of light and the photo receivers 3-5. During weaving, the fabric is reciprocated, moving forward by a certain amount for each feed of the weft yarn. In this case, the output of the distributed photodetector 3 is formed discretely; 5 varying voltage, which is then amplified by the AC amplifier 11. Next, from the resulting sawtooth pulse shaper 2

counting pulses are formed, each of which corresponds to the setting of one weft yarn. These pulses are applied to counter 8.

When the flag reaches 1 point photodetector 4, the base length of the fabric L starts counting. In this case, the photodetector 4 outputs a voltage of logical zero, and the photodetector 5 produces a logical unit. Elements NOT 6 and 7 form the signal of the logical unit of the beginning of the counting of weft threads. Counter 8 starts counting pulses. When the 1 photodetector 5 flag is reached, the counting stops, the binary-decimal code of the counter 8 is converted to decimal decoder 9, and the number of weft threads on the base length L is displayed with an indicator 10. To re-measure, you need to return the flag to its original position and reset the counter 8 readings ( reset not shown). For operation of the device, it is necessary that the length of the flag L be greater than the length of the linear photodetector 3, and the distance L between the point photodetectors 4 and 5, equal to the base length of the fabric, should not be longer than the length of the linear photodetector 3.

Claims (1)

Invention Formula A device for controlling the density of the fabric by the DUCT mainly on a loom, containing an optoelectronic unit controlling the presence of weft threads and the length of the fabric, including a light source and two point photodetectors arranged in series in the direction of movement of the fabric at a given distance from one another, and a recorder , characterized in that, in order to increase the control accuracy by eliminating the divergence from the reciprocating motion of the tissue, it is equipped with a linear photoreceiver and a flat screen made of opaque material and having a length not less than the length of the linear photoreceiver, the light source is distributed and mounted opposite the linear photoreceiver parallel to the direction of tissue movement, point photoreceivers are located along the edges of the linear photoreceiver, and the flat screen is installed with the possibility of synchronous movement with In this case, the outputs of all the photoelectric subframes between the distributed source to the corresponding inputs of the light channel and the photodetectors, with the hysteresis.