摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. A position sensor measures the position of the reel and sends a corresponding measured position signal to a position: control loop which compares the measured position signal with a reference position signal corresponding to a desired position for the motorized reel, and drives the reel in such a way as to minimize the difference between the measured position and the desired position.
摘要:
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.
摘要:
A motorized yarn-winding drum holds a plurality of loops of yarn wound thereon and is driven to rotate for drawing said yarn from a reel and feeding it to a general downstream machine. A movable guiding member is biased to slideably engage the yarn unwinding from the drum and to deviate its path, by a spring acting in contrast to the tension of the yarn, thereby generating a reserve releasable in response to tension peaks on the yarn. The stroke of the guiding member is limited by a stop defining a position of maximum deviation of the yarn. The spring has one end operatively connected to the guiding member and one opposite end connected to driving elements operable for applying a load to the spring, with the guiding member abutting against said stop. The driving elements are controlled by a control unit which is programmed to adjust the load as a function of a desired feeding tension.
摘要:
The yarn-feeder comprises a reel (R) having loops of yarn wound thereon and driven by a permanent-magnet, synchronous brushless motor to draw the yarn from a spool (RO) and to feed it to a textile machine arranged downstream (MF). The motor (M, M′) comprises a stator (STA, STA′) consisting of a substantially cylindrical, hollow housing having at least three elongated pole shoes (E1-E3, E1′-E3′) having respective excitation coils wound thereon (A, B, C, A′, B′, C′), and a rotor comprising a magnetic member having a circular profile with alternating poles, which is coaxially supported on the driving shaft (AM, AM′) near the coils.
摘要:
A motorized yarn-winding drum holds a plurality of loops of yarn wound thereon and is driven to rotate for drawing said yarn from a reel and feeding it to a general downstream machine. A movable guiding member is biased to slideably engage the yarn unwinding from the drum and to deviate its path, by a spring acting in contrast to the tension of the yarn, thereby generating a reserve releasable in response to tension peaks on the yarn. The stroke of the guiding member is limited by a stop defining a position of maximum deviation of the yarn. The spring has one end operatively connected to the guiding member and one opposite end connected to driving elements operable for applying a load to the spring, with the guiding member abutting against said stop. The driving elements are controlled by a control unit which is programmed to adjust the load as a function of a desired feeding tension.
摘要:
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. A position sensor measures the position of the reel and sends a corresponding measured position signal to a position control loop which compares the measured position signal with a reference position signal corresponding to a desired position for the motorized reel, and drives the reel in such a way as to minimize the difference between the measured position and the desired position.
摘要:
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.