2.15 Electronic Shedding Mechanism

Toyoda (loom manufacturer) has introduced the latest electronic technology in shedding. Figure 2.37 shows a schematic diagram of an electronic shedding motion. Each of the heald shafts A is connected via links B to cam C. Each cam is driven by a servo motor D and gears E and F. The servo motors are connected to an E-shed controller, a 32-bit main CPU and a function panel, as shown in the diagram.

In the function panel, the timing for shedding, dwell and shedding pattern are set according to the weaving design. The heald shafts are moved up and down, according to the settings, positively, precisely and smoothly by the servo-motors.

The E-shedding mechanism has the following features :

1. Ultimate flexibility

The E-shed combines the optimum cross-timing and dwell angle for each shedding curve. This makes it easy to weave various kinds of fabrics such as high-density fabrics, traditionally woven by cam shedding; or complex fabrics with a dooby and even fabrics difficult to weave with conventional shedding motions because of loose warp yarn or incomplete shedding.

A - Heald shaft                   D - Serve-motorB - Links                            E & F - Gears

                                  C - Cam

Figure 2.37 Electronic shedding mechanism

2. Better Fabric QualityUnlike existing shedding devices, the E-shed allows separate upper and lower dwell angles to be set, which improves beating-up performance and fabric quality. Meanwhile, combined variations in cross-timing prevent warp entanglement and minimise problems caused by warp yarn. And since the shedding and beating-up motions are not synchronized, there are fewer stop marks during star-up.

3. High Efficiency

Freely controllable warp leads to increased warp shedding ability and minimal mispicks in weft insertion. This obviously means greater efficiency.

4. Easy Operation

Settings can be changed by a touch of the function panel. This makes it much quicker and easier to be flexible when

manufacturing many different kinds of textile articles in small quantities.

5. Not Affected by Upper/Lower frame Imbalance

The E-shed is not affected by any difference between the numbers of upper and lower heald frames unlike in dobby shedding, which enables wider range of patterns to be woven with great ease.