摘要:
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.
摘要:
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.
摘要:
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).
摘要:
A weft feeder device for threads, in particular for weaving looms, of the type comprising a main body (1) within which there is housed an electric motor for the driving of a rotary shaft (2), the rotary shaft (2) driving into rotation, with its middle portion, a rotor (3), and a drum (T) rotatably mounted on the end portion of said rotary shaft (2) and kept fixed by magnetic means (6, 7), and wherein there are furthermore provided pairs of optical emitting/receiving sensors (E, R) are respectively arranged on the drum (T) and on an extension of the main body (I) of the weft feeder device which extends laterally to the lateral surface of the drum (T), said pairs of sensors (E, R) being apt to detect the presence/absence of a thread passing therebetween. The outer surface of said drum (T) consists of multiple independent sectors (4), and said emitting sensors (E) and the relative feeding and control circuit are embedded in the thickness of one (4s) of said sectors (4), arranged opposite said extension (10) of the main body (1) of the weft feeder device.
摘要:
A yarn brake includes a fixed frame, fixed and spaced-apart yarn guide elements defining together a straight yarn path through the yarn brake, a rotation drive, and at least one braking element projecting from the rotation drive beyond the straight yarn path. The braking element is controlled by the rotation drive to move through an angular stroke about a rotation axis that is spaced from and essentially parallel to the straight yarn path. The angular stroke has a starting position on one side of the path and a braking position on the other side of the path. An adjustment device varies the degree of deviation of the yarn by varying the braking position of the braking element. The distance between the rotation axis of the braking element and the straight yarn path is variable.
摘要:
A weft feeder device for threads, in particular for weaving looms, of the type comprising a main body (1) within which there is housed an electric motor for the driving of a rotary shaft (2), the rotary shaft (2) driving into rotation, with its middle portion, a rotor (3), and a drum (T) rotatably mounted on the end portion of said rotary shaft (2) and kept fixed by magnetic means (6, 7), and wherein there are furthermore provided pairs of optical emitting/receiving sensors (E, R) are respectively arranged on the drum (T) and on an extension of the main body (I) of the weft feeder device which extends laterally to the lateral surface of the drum (T), said pairs of sensors (E, R) being apt to detect the presence/absence of a thread passing therebetween. The outer surface of said drum (T) consists of multiple independent sectors (4), and said emitting sensors (E) and the relative feeding and control circuit are embedded in the thickness of one (4s) of said sectors (4), arranged opposite said extension (10) of the main body (1) of the weft feeder device.
摘要:
A weft yarn deflection brake including a braking element 5 which can be adjusted in timed fashion and by its variable braking force, a drive motor 6 for said braking element and a control device CU connected with said drive motor 6 is equipped by a position detection means E associated to said braking element 5. Said position detecting means E is connected to an adjustment means 9 for functional parameters of the deflection brake. During operation functional parameters as e.g. the braking force and the time of the activation of the deflection brake are varied adaptively in order to assure a performance of the deflection brake which is deemed to be optimal for the insertion system. At selected points in time known target positions of the braking element are set and compared with the actual positions. In case that deviations are detected a respective functional parameter is varied.
摘要:
A yarn processing system includes a weft yarn feeding device with a control unit and a power loom which consumes weft yarn. In operation, a run-signal is generated by the power loom that initializes the start-up of the weaving operation. A start-signal that is derived from the run-signal is transmitted to the feeding device. The start-signal is generated externally of the feeding device. The drive motor of the feeding device is driven at a predetermined speed, after receiving the external start-signal in order to prevent an undesired reduction of the size of a yarn store by the initial consumption demand of the start-up of the weaving operation of the power loom. A signal transmitting connection is provided in the yarn processing system between the power loom and a control unit of the feeding device for transmitting the start-signal. On start-up of the power loom, the drive motor of the feeding device is operated at a predetermined speed by the control device independent from the size of the yarn store in the feeding device.
摘要:
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.
摘要:
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). The core (7) comprises a continuous central part magnetically cooperating with the radial piece (11) of the yoke (2) and the two opposite sets of pole pieces (15, 16) axially projecting from the central part and magnetically cooperating with the sets of axial pole pieces (13, 14) of the yoke (2); in the two sets of pole pieces (15, 16) of the core (7), or alternatively in the two sets (13, 14) of the yoke (2), the pole pieces of one set are offset in respect of the pole pieces of the other set.