DD126355B1 - METHOD AND DEVICE FOR OPERATING CHAIN EQUIPMENT - Google Patents

Description

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Method and device for the commissioning of warp knitting machines

The invention relates to a method for the commissioning of warp knitting machines, in which warp threads positively supplied and the threads between the feed point and the active site are acted upon with a force, and an apparatus for performing this method.

From DE-OS 1 585 444 is known to achieve a constant feed of the yarn from the warp beam to the mechanism of a warp knitting machine at a uniform speed and under constant tension despite continuously changing warp beam diameter by a servomotor depending on the yarn tension changes the ratio for the warp beam drive ,

Furthermore, it is known in warp knitting machines, that the positively supplied warp threads run over elastic yarn jacks and between the warp beam and active site a tensioning tree is arranged, which lays in the reduction of the engine speed against the warp threads and deflects them further. The aim of this further deflection of the warp threads is to compensate for the declining at the outlet of the machine, in machine downtime going to zero dynamic forces.

The dynamic forces in the warp threads arise through the movement of the active elements within a stitch formation cycle and their effect on the different yarn requirements. With the start of the machine, the dynamic forces are restored, the deflection of the warp threads is progressively, corresponding to the change in the dynamic forces, withdrawn.

With the increase of the static tension by the deflection of the warp threads for additional application of the decreasing or missing dynamic tension an almost complete elimination of so-called stop and start rows should be achieved.

However, it has been found that these measures are not sufficient to reliably avoid the stop and start rows, since the main cause has not been eliminated. The main reason is that too much thread runs into the stitch last formed before the standstill, which makes the stitch too big.

If the static tension on the warp threads is increased when the machine comes to an end, the tapered threads are pulled tighter and, depending on the duration of the machine downtime, the thread expands because it is under additional force during the entire downtime. When starting the machine, the Kettfadenauslenkung is withdrawn. Due to the additional elongation of the warp thread is an extra thread length available, which enters as a larger mesh in the goods. It is thus caused by the increased thread tension during standstill in addition to an additional stress and strain of the thread a number of larger mesh in the product when starting the machine.

The purpose of the invention is to avoid stopping and starting lines due to different mesh sizes in the goods when commissioning warp knitting machines.

The invention has for its object to provide a method and an apparatus with the help of all meshes in arrival and departure of the machine of equal size meshes are formed during standstill of the machine, the mesh size is not changed and the warp threads no significant additional elongation experience.

According to the invention, this object is achieved in that during the last phase of the machine standstill, the warp threads are subjected to an additional force, the

is lifted with the machine start.

According to another feature of the invention, a servomotor has a manually operable power switch. The servomotor controls the bias of the Padenwippen and a programming device, the power switch of the main drive and the switch off the servomotor.

The advantage of this method and this device is that the stop and start rows in the product no longer occur or are greatly reduced, thereby improving the quality of the product and also an increase in productivity is recorded, as the afflicted with stop and start rows piece Goods had to be cut out of the running web.

The invention will be explained in more detail below with reference to an embodiment. The drawing shows a side view of the device according to the invention.

The device consists of a servomotor 1, on whose output shaft 2, the cams 3, 4, 5 are clamped next to each other. At the cam 3, the sensing roller 6 of the switch 7 is for the main drive and on the cam is the sensing roller 8 of the switch 9 for the servomotor. On the cam 5 is mounted by the tension spring 13 of the shaft 20 mounted on the double lever 11 with its roller 12. At the other end of the double lever 11, a tension spring 10 is fixed, which is connected to the Padenwippe 14. At the upper end, the thread rocker 14 carries the thread guide 15 · For better support of the Fadenleitmittels 15 over the entire working width of the machine, it is advantageous to fasten on the shaft 16 a plurality of thread rockers 14. For this purpose, the shaft 16 is mounted on both sides and rotatably in the machine frame. About the Fadenleitmittel 15 coming from a continuous and slip-free yarn delivery 17 warp threads 18 of the active site 19 are supplied.

If the machine is to be switched on, the main switch is actuated, via which the servomotor 1 is started. As a result, the output shaft 2 is in motion with the cam disks 3; 4; 5.

The cam 5 pivots in its rotation, the double lever 11 counterclockwise about the shaft 20. As a result, the yarn jacks 14 via the tension spring 10 bzv /. Shaft 16 is also rotated counterclockwise, the yarn guide 15 lays against the warp threads 18, this applied with an additional force and thereby pulls a predetermined length warp thread 18 from the last stitch back.

The condition is that the yarn delivery 17 works without slippage. When v / eiteren rotation of the cam 5 rolls the web of larger diameter, the roller 12 is again at the smaller diameter. The double lever 11 has returned to its original position. On the thread rocker 14 again acts the normal spring force of the tension spring 10. Simultaneously with the cam 5, the cam disks 3 and 4 run around. At the time when the roller 12 is at the transition from the large to the small diameter of the cam 5, the eccentric part of the cam 3 hits the follower roller 6 and raises it. Thus, a contact is closed in the power switch 7 and the main drive of the machine starts to work. The cam 4 is set to the cam 5 so that the eccentric portion of the cam 4, the sensing roller 8 lifts when the cam 5 has completed a revolution and is back in its initial position. When lifting the feeler roller 8, the current flow to the servo motor 1 is interrupted via the switch 9, it stands still and thus the cams 3, 4, 5 # As can be seen, the cams 3, 4, 5 are adjusted to each other or the touch rollers 6; 8 are so along the circumference of the cam discs 3, 4 adjustable that the required time-travel settings for the cam 5 are possible.

The time from when the additional force acts on the warp thread is set when the machine is switched on.

The duration of action of this force is set with the setting of the cams 3, 4, 5 and the feeler rollers 6, 8 to the cam 5.

The additional force can be withdrawn prior to or at the start of the machine as well as only during normal operation of the machine.

Advantageously, the additional force is withdrawn with the engine start-up to obtain approximately equal warp tension for the loop-forming cycles.

Claims (2)

claims 1. Method for starting up warp knitting machines, in which warp yarns fed positively and the threads between the feed and the knitting are subjected to a force, characterized in that during the last phase of the machine standstill, the warp threads (18) are acted upon with an additional force which is released with the machine start , 2. Apparatus for carrying out the method according to claim 1 to warp knitting machines with a main drive and an associated main switch, with a servomotor for the control of Fadenablenkmitteln and the servo motor associated programming device, characterized in that the servomotor (1) a switch and at least one cam associated with the yarn jacks (14), with the skin drive power switch (7) and with the actuator switch (9) * See drawings!