SU1509451A1 - Method of controlling sewing machine - Google Patents

Abstract

The invention allows to take into account the length of the remainder of the thread in the spool. When the thread is being wound on the spool, the length of the thread is controlled, and on a certain section of the thread with the help of a special dyeing device, check marks are applied. Labels are applied to the thread section, which is separated from the start of winding at a distance equal to the consumption of the thread for processing one (last) piece. The occurrence of the label area in front of the photovoltaic device is a signal of a sufficient amount of the lower thread for processing only one last preform. The signal from the photo sensor is converted into an electric one, and when a variable component of this signal appears, the prohibition scheme for processing the next workpiece is triggered, which permits the processing of the workpiece to be completed, but the processing of the new one is prohibited. The sewing machine stops and the operator must change the spool. 6 Il.

Description

The invention relates to sewing production, to shuttle sewing machines and semi-automatic machines and can be used during winding and unwinding operations in the textile, printing, electrical and radio engineering industries.

The aim of the invention is to increase the control accuracy by taking into account the length of the remainder of the thread in the spool.

The essence of the invention is that check marks are applied to the thread while winding it onto the spool. The area of the marked area in front of the photovoltaic device is

signal a sufficient amount of the lower thread on one workpiece.

FIG. 1-5 show diagrams for explaining the proposed method; figure 6 - timing diagrams.

In mass production, the length of the yarn is determined, which is spent on processing a single piece. When winding on the spool, the length of the thread is monitored by the counter 1 (Fig. 1) and using the printing device 2, a number of marks are drawn on the section located from the beginning of the winding at a distance equal to the length of the thread consumed to process one piece. By appearance

SL

ABOUT

  ate

31509

these tags during sewing will give a signal that the thread length remains on the spool, which is sufficient for processing only one piece.

When sewing during weaving of a stitch, the thread is always briefly pulled over a section of shuttle 3 (Fig. 2). This area of the shuttle is illuminated by the illuminator A and the lens 5 of the photo-detector 6 is directed to it, with the help of a lens a small spot through which the shuttle thread passes is shown (Fig. 3). When the thread goes without tags (Fig. 3) the integral value of the illumination is constant. When passing through a portion of the thread with sealed marks (Fig. E), the luminance of the viewed spot changes and a variable component is superimposed on the constant integral illumination.

Constant integral illumination of the filament yields a constant voltage at the output of the photodetector (Fig. 5a). With the passage of the recorded marks in front of the lens of the reading device, a variable component appears on the background of a constant voltage from the integrated brightness of the viewed area (Fig 5 b). In order to prevent false alarms when a needle thread is circumflex around the shuttle, a sensor is installed on the main shaft of the sewing machine, which outputs strobe pulses (Fig. 5e) only at the moment: stitch weights, i.e. when moving the thread under the lens of the photodetector.

The variable electrical signal from the photo sensor 7 (Fig. 6) is fed to a coincidence circuit 8 (circuit I), to the second input of which gating pulses are received from the sensor 9

The main shaft of the sewing machine, at the output of the coincident circuit, a variable signal rectified by diodes 10 and 11, charges capacitor 12. At capacitor 12, voltage U. rises with each stitch until it reaches the trigger voltage (Fig. 3g), sufficient to activate the shuttle thread 13 control device 13.

A variable signal can occur only during sewing, so the marked area should have a length of several stitches. In the process, this small area with sealed tags goes to the wrong side of the workpiece, which does not reflect the quality of the product.

I

The signal of the shuttle thread supply received by the actuator 13. permits the processing of the started workpiece to be completed, but prohibits the processing of the next workpiece and signals this gateway to the operator.

Claims (1)

Invention Formula The method of controlling the sewing machine, which consists in determining the stock of the thread and stopping the machine, characterized in that, in order to increase the control accuracy by taking into account the length of the remainder of the thread on the spool, before processing the products, the length of the thread required to sew one workpiece is determined, and At a certain section of the thread, before its winding, check marks are put on the spool, and the machine is stopped to appear on these marks, but after the completion of the workpiece preparation cycle. / 7 ///// Phie. Z fme.5 and / 7777/77 Phie.1 Fiel one f and zJ J and HAL-HAL / with Ucp Yu ) 3 / g. Fi.by P FIG. 6