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contact, along an essentially circular braking zone (Z), with a rim (W) of said drum (4) from which the yarn (Y) is withdrawn, and a flexible and wearproof friction surface structure (S) provided on said braking portion (P) in said braking zone (Z)—said friction surface structure (S)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: During weft yarn insertion in a loom, as the end of weft yarn insertion approaches, a controllable yarn deviation brake (B), positioned between a weft feeder (M) and a warp shed (F) of a loom (D) brakes the weft yarn (Y) with a high braking force, causing a deviation of the yarn deviation brake which subsequently smooths down a tension peak of the yarn, so as to partially reduce the yarn brake deviation back towards the starting position, or position having no deviation. The same function is performed upon cutting of the weft yarn (Y). After braking and reduction of the yarn tension peak, during the weft insertion step, the braking force is reduced to a level correlated to the yarn tension which prevails up to cutting of the weft yarn (Y).

Abstract: Device to block weft yarn associated with a measuring weft feeder for fluid jet looms. The device is located downstream of the outlet yarn guide and/or of the antiballoon device of the feeder, and comprises a single elongated body which includes: an inlet cone and a cylindrical channel crossed by the weft yarn, the common axis of which is the longitudinal axis of the device; a core to block the yarn, movable into a guide perpendicularly to the axis and adapted to penetrate into the channel through an opening thereof; electromagnetic elements acting on the core against a return spring; and a bush associated to the channel, in correspondence of the opening, to form a contrast surface onto which the core engages in order to block the yarn.

Abstract: An electromagnetic unit to stop the weft yarn in measuring weft feeders for fluid jet looms, includes a rod movable along its axis under the control of at least one electromagnetic coil so as to insert one of its ends, with slack, into a corresponding hole of the weft feeder drum and engage with that end the weft yarn on the side to stop its unwinding from the drum. Onto the movable end of the rod engaging the weft yarn a bush is mounted for mating with the edge of the drum hole for insertion of the rod end, and the sliding of the bush towards the drum taking place with delay in respect of the movement of the rod towards the drum.

Abstract: Device to control the yarn at the outlet of yarn feeders, particularly antiballoon device for weft yarn feeders of looms, of the type consisting of an element (10) having a substantially frustoconical surface. A plurality of ribs (11) project from the inner wall of said element, substantially extending along the generatrices of its surface.

Abstract: Electromagnetic actuator with rotary core, comprising, housed in a casing: a magnetic yoke, a pair of fixed adjacent coils alternately energized, and a rotating element with a magnetic core; the yoke, the coils and the core having a common axis coinciding with that of the actuator, and the core being positioned between and/or within said coils, so as to close alternative circuits of magnetic flux, generated in the yoke by either one of the coils, between opposite axial pole pieces and central radial pole pieces of the yoke. In the actuator: the yoke (2) comprises a single radial pole piece (11) common to both coils (3, 4) and two sets of axial end pole pieces (13, 14).

Abstract: Yarn feeding device for projectile or gripper looms, having a drum (D) to store the yarn (Y), an inclined annular deflection surface (G) at the free front end of the drum (D), a circumferentially continuous and yielding conical braking surface (B) at the wider end of a hollow conical brake carrier (C), pressed in contact with the deflection surface (G). The brake carrier (C) is supported at its smaller end onto a stationary part (P) and the braking surface (B) is adjustable with respect to the deflection surface (G), according to the yarn unwinding speed, so as to compensate for any tension increase in the yarn (Y), and an annular counterdeflection surface (H) for the yarn (Y), downstream of the deflection surface (G) and coaxial to the drum (D). The inside diameter of the counterdeflection surface (H) is smaller than the outside diameter of the deflection surface (G).

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: From a weft feeder (AT), weft yarn (T) is unwound from a reserve (R) on a drum (3) located at an outlet end of the weft feeder (AT). A yarn-braking device (1) includes a frustoconical braking element (6) with varying flexibility and a cup support (8) with an open base. The braking element (6) has narrow tongues (7) placed side-by-side. In the braking element (6), the tongues (7) join together, at a major circumference, into a band (6A) with a smoothly and strictly continuous surface engaging an outlet end of the drum (3), while they are free and freely bear, at a minor circumference, against an inner periphery of the cup support (8). The braking element (6) is connected to the cup support (8) such that the former can be deformed and/or perform limited movements in every direction. An outlet yarn guide (4) is separate from the braking element (6) and is kept motionless, coaxial to the drum (3), while braking takes place.