Abstract: A yarn recovering device for textile machines, arranged upstream of a textile machine for temporarily recovering a length of yarn previously fed to the machine, and for returning it subsequently. A motorized reel has a substantially axial inlet port and an outlet port on its lateral surface, with a passage for the yarn between the ports. The reel is operatable to rotate from a resting configuration, in which it is kept still, to an active, yarn-recovering configuration, in which it is driven in one direction for winding the yarn on itself and recovering it from the machine, to a subsequent active, yarn-unwinding configuration, in which it is driven in the opposite direction for unwinding the yarn from itself and returning it to the machine.

Abstract: A yarn recovering device for textile machines, arranged upstream of a textile machine for temporarily recovering a length of yarn previously fed to the machine, and for returning it subsequently. A motorized reel has a substantially axial inlet port and an outlet port on its lateral surface, with a passage for the yarn between the ports. The reel is operatable to rotate from a resting configuration, in which it is kept still, to an active, yarn-recovenng configuration, in which it is driven in one direction for winding the yarn on itself and recovering it from the machine, to a subsequent active, yarn-unwinding configuration, in which it is driven in the opposite direction for unwinding the yarn from itself and returning it to the machine.

Abstract: A self-adjusting braking device for weft feeders, comprising a frustum-shaped braking body that acts on a thread, is suspended elastically in front of the drum of the feeder and is pushed into elastic tangent contact with the drum along an exit circumference of the drum. The braking body has, at a larger-diameter region thereof designed to make contact with the drum, a discontinuous annular contact element, with a plurality of through slits which are arranged so as to be equidistant and delimit a row of contact laminas.

Abstract: An anti-balloon device, to be placed downstream of a weft feeder for weaving looms, comprising a structure which forms a substantially tubular through cavity, preferably substantially frustum-shaped; the cavity is crossed by an unwinding thread that arrives from the weft feeder and controls the passage of the thread, by opposing the centrifugal force that affects it. The structure is shaped like a bottomless basket which is formed by rods lying longitudinally between end elements which connect the rods; the end elements are end rings which are mutually angularly spaced so as to surround the cavity in order to control the passage of the thread.

Abstract: A self-adjusting braking device for weft feeders, comprising a frustum-shaped braking body that acts on a thread, is suspended elastically in front of the drum of the feeder and is pushed into elastic tangent contact with the drum along an exit circumference of the drum. The braking body has, at a larger-diameter region thereof designed to make contact with the drum, a discontinuous annular contact element, with a plurality of through slits which are arranged so as to be equidistant and delimit a row of contact laminas.

Abstract: The method consists in determining the angular positions of the rotor, which are useful for switching the phase currents, by deducing them from the sampled reading of the phase voltages, and in measuring the current of each phase by deriving it from the detection of the voltage that is present across a shunt resistor inserted on the negative power supply conductor of the three-phase star bridge of the driving inverter that generates the set of three phase voltages supplied to the motor.

Abstract: A method for controlling electrically actuated weft brakes for automatically adjusting mechanical tension of a weft thread in textile machines with mechanical insertion, comprising the steps of: generating and modulating an excitation current of an actuator of an electrically actuated brake. The above step is performed with a device which comprises a control chip which is sensitive both to variations of mechanical tension measured on the left thread and to an actual value (v) of a travel speed of the weft thread during insertion; the control loop is adapted to recondition a reference parameter of the braking action, determined by the control loop on the basis of a reference tension and a measured tension, with a multiplication factor which is represented by a decreasing function [f(v)] of the actual value (v) of the travel speed of the weft thread.

Abstract: An anti-balloon device, to be placed downstream of a weft feeder for weaving looms or the like and particularly downstream of a pre-measuring weft feeder for air jet looms, comprising a structure which forms a substantially tubular through cavity, preferably substantially frustum-shaped and suitable to be crossed by an unwinding thread that arrives from the weft feeder and suitable to control the passage of the thread, by opposing the centrifugal force that affects it. According to the invention, the structure is shaped like a bottomless basket which is formed by rods lying longitudinally between end elements which connect the rods, typically end rings which are mutually angularly spaced so as to surround the cavity in order to control the passage of the thread.

Abstract: A weft brake for weaving looms, comprising a rigid, fixed and flat plate made of non-magnetic material and a flexible lamina made of magnetic material, between which a weft thread slides; the flexible lamina is actuated magnetically against the rigid and fixed plate by the action of a plurality of permanent magnets which are supported by a movable yoke; the yoke is subjected to an electric actuator which moves the yoke with respect to the lamina, moving the magnets towards or away from the lamina; due to this action, the attraction applied by the magnets to the lamina varies and accordingly varies the pressure that the lamina applies to the thread.

Abstract: A device for moving and controlling a weft winding arm in weft feeders for weaving looms, comprising a switched-reluctance motor which is controlled by a first closed loop for speed control, having its own reference variable and its own measured variable, and by a second closed loop for controlling the current that circulates in the phase of the motor, also having its own reference variable and its own measured variable; the reference variable of the first loop corresponds to the rotation rate that the winding arm must assume in order to correctly restore the turns of the weft reserve, and the reference variable of the second loop is constituted by a current value computed by the first control loop.

Abstract: Device for modulated braking of a weft yarn for textile machines, comprising a set of three yarn guiding eyes, which form a straight path for the yarn, and an oscillating lever, which is connected to a U-shaped braking, element which straddles a central eye of said eyes and engages the yarn in free portions that lie between said central eye and the end eyes of said eyes in order to divert its straight path for braking, wherein the oscillating lever is controlled by an electromagnetic actuation means which comprises at least one permanent magnet which is constituted by a cylindrical body having a N-S polar axis arranged radially; the body is associated with a stem which is articulated to the oscillating lever and can move in a linear fashion inside a cylindrical shroud with high magnetic permeance, on which at least one coil is wound, an excitation current flowing through the coil; is the axis of the cylindrical shroud, which coincides with the axis of the movable stem, being perpendicular to the polar axis of

Abstract: A device for stopping the yarn for premeasuring weft feeders of air-jet looms, of the electromagnetic type, comprising a stop finger which can move radially with respect to a drum of a weft feeder and is adapted to laterally engage a yarn in order to block its unwinding from the drum. The device further comprises at least one permanent magnet which is constituted by at least one cylindrical body in which the polar axis is orientated radially. The cylindrical body is associated with a stem which is provided with the stop finger and can move in a linear fashion inside a cylindrical surface on which at least one coil is wound, an excitation current flowing through the coil. The axis of the cylindrical surface, which coincides with the axis of the movable stem, is perpendicular to the polar axis of the cylindrical body of the permanent magnet.

Abstract: A feeler for monitoring a thread reserve in weft feeders, comprising a light-emitting device constituted by a light source which directs light rays onto a thread wound in spaced turns on the drum of the feeder, and a receiver which collects the light rays and converts them into electrical signals that indicate the presence or absence of turns of thread. A first focused optical transmission system forms a first pointlike luminous image of the light source on the turn being monitored and, in the absence of the turn, a second pointlike luminous image of the light source located on a screen surface which is arranged below the turns. A second focused optical projection system selectively projects the first or second luminous image, along respective differentiated optical paths, onto at least one optical sensor which emits discriminated signals that correspond to the length of the corresponding optical paths.

Abstract: A device for spacing the turns of thread for weft feeders, which comprises a set of turn movement rods which are connected to a hub by respective spokes, wherein the hub is mounted so that it can rotate freely on a bush which is fitted on an eccentric portion of the driving shaft of the feeder and is inclined at a constant angle with respect to the axis of said eccentric portion in order to cause the cyclic and partial protrusion of the rods from corresponding slots of the drum of the feeder, and wherein the keying angle of the bush on the eccentric portion of the driving shaft is variable in order to correspondingly vary the spacing pitch of the turns on the drum. According to the invention, the axis of the bush, in the configuration in which the keying angle is zero, intersects the axis of the driving shaft in a point which is adjacent to the free end of the drum and is located, relative to the advancement direction of the thread, downstream of the transverse plane that contains the axes of the spokes.

Abstract: A weft feeder in which a variable-diameter drum receives from a windmilling arm multiple turns of thread that form a weft reserve, and in which a variable-diameter swift is associated with the drum to transport the turns from the base of the drum to its head; the swift is formed by multiple rods which protrude in a cyclic manner from corresponding slots of the drum; the extent of the protrusion of the rods from the slots determines the mutual distance between the turns of the thread reserve. The swift and the drum are formed by corresponding sectors that are radially movable and are controlled by respective radial shifting mechanisms, each of which comprises at least one actuation gear that meshes with individual gears for shifting the respective drum and swift sectors. The pair of actuation gears is turned by a single transmission element which is controlled by an actuation knob that is also used to vary the extent of the protrusion of the rods.

Abstract: The device comprises a container, closed by a lid, for holding the lubricating fluid; a strip of felt or the like is immersed in the container and becomes impregnated with the fluid by capillary action. One end of the strip protrudes from the lid of the container and wraps around a cylindrical support so that a respective portion of the strip, shaped like a cylindrical sector and impregnated with lubricating fluid, protrudes with respect to the surface of the lid and is exposed. The weft thread to be lubricated is made to slide on the exposed portion of the strip, and means are provided for guiding the thread and for producing a cyclic transverse movement thereof from one end to the other of the exposed portion.

Abstract: A weft feeder comprising weft sensors with movable magnetic elements that cooperate with respective detectors located outside the feeder drum; the detectors react with a signal, without contact, when the position of the corresponding weft sensor changes. Each detector in turn comprises an acquisition sensor capable of providing an analog signal, in terms of voltage, that can vary in a linear manner as the angular positions of the movable magnetic elements of the weft sensors vary. The acquisition sensors are operatively connected to a microprocessor for controlling the motor of the feeder, which is programmed to automatically set the values of the weft presence threshold and of the weft absence threshold and to filter the values of said signals.

Abstract: A rotatable thread arrester, associated with a thread feeder, includes an arrester finger for the thread that is movable with respect to the reel of the feeder under the control of a movement device and engages the thread so as to stop its unwinding from the reel and viceversa in order to damp the peak of the mechanical tension generated on the thread by the contact with the arrester finger. The arrester finger is oscillatably suspended about an axis "x" that is parallel to the axis "y" of the reel and is controlled by the action of a motor which rotates the arrester in the thread unwinding direction, so that the arrester finger, in the arresting position, follows the thread unwinding from the reel.

Abstract: Device for positive modulated braking of weft feeder thread, including a braking body, typically a frustum-shaped braking body, that is supported frontally and coaxially to the drum of the feeder in order to directly or indirectly engage the thread that unwinds from the drum. The braking body is subjected to the action of an electromechanical actuator, supplied by an excitation current that is modulated so as to match the variation in the mechanical tension of the thread during the weaving process; the braking body is rigidly coupled to a support that is movable in the axial direction of the drum of the feeder and is supported and guided by a fixed support.