摘要:
Yarn feeder including a body carrying a drum on which turns of yarn from a spool are wound; a tension sensor for measuring exiting yarn tension value, a braking member including a first permanent magnet and a fixed second magnet, regulator for varying action the second magnet exerts on the first permanent magnet, and a control unit to control the regulator. The first magnet is annular and movable parallel to the axis of the drum and along it between a first position where the first permanent magnet enables pressing the yarn against a counteracting element fixed to the drum and a second position where this effect does not occur. The control unit receives tension values measured by the tension sensor, comparing them with a predetermined value and intervening in real time on the regulator to adjust tension value to predetermined value when these two values do not coincide.
摘要:
Yarn feeder including a body carrying a drum on which turns of yarn from a spool are wound; a tension sensor for measuring exiting yarn tension value, a braking member including a first permanent magnet and a fixed second magnet, regulator for varying action the second magnet exerts on the first permanent magnet, and a control unit to control the regulator. The first magnet is annular and movable parallel to the axis of the drum and along it between a first position where the first permanent magnet enables pressing the yarn against a counteracting element fixed to the drum and a second position where this effect does not occur. The control unit receives tension values measured by the tension sensor, comparing them with a predetermined value and intervening in real time on the regulator to adjust tension value to predetermined value when these two values do not coincide.
摘要:
There is disclosed an intermediate yarn feeding and control device having a storage member adapted to have yarn wound thereabout adjacent one end thereof to form yarn windings which advance toward the other end thereof. Yarn guide means located adjacent the other end of the storage member is adapted to guide the yarn, selectively, into one of two separate paths of yarn travel. A restraining element restrains the yarn withdrawal to a preselected rate when the yarn is guided through one of the paths but is clear of the yarn travel when the yarn is guided through the other of said paths for permitting the yarn to be withdrawn from the storage member at any desired rate. The yarn guide means includes a plurality of outwardly extending resilient fingers whose free ends support an outer ring so that when the withdrawn yarn is guided through the one path which is inwardly of the outer ring, it flexes successive resilient fingers which impart thereto a preselected tension.
摘要:
The yarn tension is modulated by a yarn-braking device controlled by a control unit which receives signals of measured tension from a tension sensor and compares them with a reference tension signal in a control loop; as long as the reference tension remains unchanged, a first set of coefficients is used in the control loop causing the control loop to have a relatively slow behavior in relation to the error-compensating action; when a change in the reference tension occurs, the system switches to a second set of coefficients causing the control loop to have a relatively fast behavior; the second set of coefficients is maintained as long as the difference between the second value of the reference tension and the measured tension remains greater or equal to a predetermined minimum value, then the system switches again to the first set of coefficients.
摘要:
A yarn braking body is a flexible frustocone coat made from plastic material and has a circumferentially continuous braking surface which is defined by a part of the inner surface of the frustocone coat. The yarn braking body has a circumferentially continuous support part at the small diameter end. The support part is spherical and one piece with the frustocone coat and is made from the plastic material of the yarn braking body such that the centre of the sphere lies in the axis of the frustocone coat which axis is prolonged beyond the large diameter end.
摘要:
Device for controlling the balloon and tension in the thread from a thread storing and distributing apparatus to textile machines. Such a device comprises a bell superimposed to the storing apparatus and supported thereon by flexible fingers which are deflected by the thread unwinding from the apparatus.
摘要:
A device for feeding yarn to a textile machine, including a main body defining an entry portion and an exit portion for yarn; a rotatable drum for winding the yarn originating from the entry portion and a motor connected to the drum for rotating the drum; a control member active at least on the motor to regulate its torque and velocity; exit portion being selectively switchable between a first configuration in which it defines a free exit section for the yarn, through which the exiting yarn defines a closed path about a rotation axis of the drum, and a second configuration in which it defines a limited exit section, through which the exiting yarn defines an open path.
摘要:
A yarn feeding device for feeding yarns to weaving and knitting machines and devices with a constant, adjustable tension, in which a yarn reserve is wound onto a stationary cage by means of a rotating framework. The device also comprises means for braking the yarn, and means for regulating the action of said brake means and for modifying the amount of said reserve. In this device, the yarn is drawn with a constant tension, and is sent to the weaving or knitting machine or device as if it were drawn from a stationary reserve.
摘要:
A yarn storage drum is provided with a separate external support for holding a plurality of yarn tension rings in selectively spaced, stacked relation. Each ring includes spacer means for supporting a next-above ring. Each ring has an annular set of elongated fingers which project from the base of the ring and incline toward the storage drum and also circumferentially thereto. The fingers of the lower rings overlap those of the upper rings, and the tips of the two fingers of each ring contact the periphery of the drum and together apply a selected uniform tension to the yarn. The tension rings are free to float transversely with respect to the drum.
摘要:
A retarding device surrounding a storage drum adapted to have yarn wound tangentially thereon and unwound axially therefrom. The retarding device comprises a coiled spring whose opposite ends are secured to form a continuous retarding ring having an inner contour smaller than the outer contour of the drum before the ring is mounted on the drum whereby the ring is placed under tension when mounted on the drum. Each coil of the spring has a curved portion in bearing engagement against the drum which defines a constant resistance to the yarn which passes thereunder as it is axially withdrawn from the drum.