The projectile weaving machine made its appearance in the market at the beginning of the 50’s and is today still used in the whole world. Thanks to its steady renovation and to the use of advanced electronic systems as well as of microprocessors for the supervision and the control of the various devices, this machine is characterized by a good productivity level (450 rpm and 1050 m/min of inserted weft) and by high operational reliability. It is established especially in the field of machines with high reed width.
General Operation
Projectiles: there are various projectile versions: made of steel, 9 cm long and 40 g heavy, with small section, as suitable for yarns of fine to medium count; made of steel, 9 cm long and 60 g heavy, with large cross-section which, thanks to their higher weight and to the larger clamping section of the gripper, are particularly suited for machines with high reed width or when for weft bulky yarns, as e.g. fancy yarns, are used.
In this weaving machine the weft insertion is carried out by small clamp projectiles (fig. 45), which number depends on the weaving width and which with their grippers take out the weft yarn from big cross-wound bobbins and insert it into the shed always in the same direction. The projectiles work in sequence, that is they are launched in succession. They run therefore one after the other, describing in the space a continuous, endless route, as if they would be stuck on a conveyor belt.
The first projectile takes and holds in its back the weft in form of a tail; then, pushed by the release of the projectile thrower, it passes through the shed and deposits the weft inside the warp; subsequently the projectile falls and is collected by a device which, by passing under the array of the warp threads, takes it at reduced speed back to the starting point. Here the projectile goes up to take up a new weft; meanwhile the other projectiles have run after each other making the same operation.