Wednesday, 26 August 2009

Pattern Drives on Warp Knitting Machines

Although many modern types of warp knitting machine with electronic control guide bar drive (EL)or S U aggregate drive are available nowadays,however still many warp knitting fabric manufactures are still using conventional warp knitting machines with chain links which drive with mechanical pattern drive instead of electronic control guide bar.
Even Karl Mayer release new type machine ML 33 CD made in Karl Mayer China,which using mechanical pattern drive control EH for guide bars and E type on the left side for ground bars.

The pattern drive, control the lateral displacement shog of the guide bars on the warp knitting machines.
According to the requirements there are several pattern disk which can be basically divided into one drum and two drum pattern drives.
Pattern drives are called convertible if different machine gauges can be run with chain links on the same gauge.

The most common pattern drives:

One drum drive :

N-Drive : The drum circumference has 48 chain links. The drive is designed for pattern repeats of 10 12, 14 16, 18 and 24 courses.

E-Drive :The drum circumference has 16 chain links The drive can be equipped with sliders or shog lever and is mainly used an Raschel machines.

Two drums drive

NE drive : Two drum pattern drives with N pattern drum for the stitch forming guide bars and E drum for weft insertion (inlay) bars. N and E pattern drums are positioned on the same pattern wheel shaft (warp knitting machine RJPC 4 F NE)

EH drive: is used an multibars raschel machines.Because the Pattern guide bars only carry out under-lap displacements (inlays), a two drum pattern drive is used which controls the ground guide bars and the pattern guide bars separately.
The upper drum for the ground guide bars works with two chain links (2 tempo)per stitch forming process.
The lower drum for the pattern guide bars, however works at reduced speed with one chain link per stitch forming process (1 tempi).
The latter is called H drum because chain links of half height are used (transmission ratio:pattern drum-push rod 1:2 is ensure by the shape of shoging lever).EH drives are convertible.

NCC drive :This drive (of type RDS 11) controls the guide bars via two pattern wheel shafts and the shog lever control. The lower pattern wheel shaft is activated via the rolling key clutch and the switching unit. The upper pattern wheel shaft runs permanently. The shog lever control is looked or unlocked via the machine computer EMC/3 and thus controls the guide bars L2 and L 10. The lifting magnet control system of the lower pattern wheel shaft is controlled via the EMC/3 computer.
N= upper pattern wheel shaft for pattern ground (1).
N= lower pattern wheel shaft for joint seam and contact-ends (2)
C= computer for controlling the shog lever control system (3) and the lifting magnet control system (4) for the lower pattern wheel shaft.

EEC drive : For the production of fabrics with simple basic lapping which change after big distanced the different lapping are by turns worked from two pattern drums which knitted on the same guide bar thus avoiding long pattern chains.
A computer controls the pattern drums. For the production of tights artificial blood vessels etc
The pattern drives are driven by the main shaft. The transmission ratio between main shaft and pattern drive determines how many chain links per stitch course are needed. This ratio is also
called Tempo :2 Tempi = 2 chain links per stitch course. When using pattern discs and with changing repeats it is possible to change the Tempi by means of a preset gear (no standard equipment).