Abstract: A yarn feeding device B of a weaving machine W comprising at least two yarn feeding appliances F1, F2 delivering the same yarn quality in a weft mixing process. Each yarn feeding appliance comprises a variable speed control system C, a sensor arrangement 6 which supplies control signals for the size of the stored yarn supply, and t least one fault sensor Z1, Z2, by which means a fault signal X indicating a change in the weft mixing condition, e.g. a yarn break in the upstream from the stored yarn supply, can be emitted. A fault signal transmission link Q1, Q2 is provided extending from each yarn feeding appliance to the speed control system C of each other yarn feeding appliance, and an over-regulating routine 6 is provided in each speed control system C, said routine enabling the speed to be increased before the change in the weft mixing condition, by means off the fault signal X, independently from the control signals of the sensor arrangement 6.

Abstract: In a yarn braking device (B) of a yarn feeder (F) for looms—of the type comprising an annular brake element (E) having a substantially conical and circumferentially continuous braking portion (P), of which at least the radial flexibility is significant and which is positioned coaxial to a body shaped as a drum (4), around which is wound a weft yarn reserve, under an axial spring load (K) and in peripheral contact, along an essentially circular braking zone (Z), with a rim (W) of said drum (4) from which the yarn (Y) is withdrawn, and a flexible and wearproof friction surface structure (S) provided on said braking portion (P) in said braking zone (Z)—said friction surface structure (S) is formed by a plurality of separate elements (C) contacting said braking portion (P) in said braking zone (Z) and movable one in respect of the other.

Abstract: Yarn feeder, especially to feed the weft yarn to gripper or projectile looms, wherein the weft yarn is unwound from a weft yarn reserve wound on a drum, onto the outlet end of which there acts a yarn braking device upstream of an outlet yarn guide. The yarn braking device, centered on the drum axis and adjustable along the drum, comprises a frustoconical braking element having a continuous surface and varying flexibility, especially along its generating lines. The yarn braking device is carried by a stiff ring support to which it is fixed close to its major circumference. The support is in turn fixedly mounted onto a bracket of the yarn feeder, the position of which is adjustable along the drum axis.

Abstract: Device to feed yarn to machines making use thereof, particularly the weft yarn (T) to gripper or projectile looms, of the type in which the yarn to be feed is unwound from a reserve (R) wound on a drum onto the outlet end of which, where a first yarn deviation takes place, there acts a brake device (FR) which is centered on the drum axis and adjustable along the same, upstream of an outlet yarn guide where a second yarn deviation takes place. The brake device (FR) comprises a frustoconical braking element with continuous surface and differentiated elasticity, carried by a stiff ring support to which it is fixed close to its major circumference, and the stiff ring support is mounted so as to oscillate about two axes (S1, S2) which are perpendicular one in respect of the other and both in respect of the axis of the drum.