摘要:
A device for temporarily storing yarn for immediate use by a yarn consuming textile apparatus, such as a winder, a knitting machine, or for the filling thread of a shuttleless loom. The device includes a yarn collecting drum on which yarn from a supply source is wound temporarily and then removed under a controlled, uniform tension. The device eliminates the wide variations in yarn tension which occur when a yarn is delivered from a source, such as a cone or a package, and permits the yarn to feed to a textile machine at a substantially constant tension.
摘要:
Accumulation-type thread feeder including: a body, which bears a rotary drum on which turns of thread from a spool are wound; a tension sensor for detecting value of tension of exiting thread and a detector for detecting thread quantity accumulated on the drum; a light-reflecting element on the drum or functionally associated therewith, such light generated by light a generator borne by a support arranged alongside the drum, the support associated with a detector to detect light reflected by the reflecting element, the reflected light varying as a function of the quantity of thread wound on the rotary drum, the detection allowing detection of such thread quantity. The detector is a light-sensitive member directly receiving the light reflected by the reflecting element along the entire surface of the drum, the member allowing determination of thread density on the drum.
摘要:
A storage feed device for a yarn which unwinds from a corresponding bobbin and is fed to a textile machine. The device includes a rotary or fixed drum and an optical sensor member arranged to sense the movement of the yarn towards the textile machine. The optical sensor includes a plurality of emitters and receivers between which a light beam is generated and is interrupted by the yarn during its movement. The optical sensor includes a first fixed part and a second fixed part which includes the emitter and receiver elements, the first part being coaxial with the rotary member, the second being annular and surrounding the first part, the yarn moving between the parts.
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 behaviour 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 behaviour; 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 storage feed device for a yarn which unwinds from a corresponding bobbin and is fed to a textile machine. The device includes a rotary or fixed drum and an optical sensor member arranged to sense the movement of the yarn towards the textile machine. The optical sensor includes a plurality of emitters and receivers between which a light beam is generated and is interrupted by the yarn during its movement. The optical sensor includes a first fixed part and a second fixed part which includes the emitter and receiver elements, the first part being coaxial with the rotary member, the second being annular and surrounding the first part, the yarn moving between the parts.
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:
The invention relates to a method for controlling a weft yarn feeding device F in a yarn processing system, comprising, in addition to the feeding device, a power look L which consumes weft yarn Y on operation, whereby a run-signal is generated by the power loom which initialises the start-up of the weaving operation. The run-signal also is transmitted to the feeding device, essentially simultaneously with a start-signal X, generated externally of the feeding device. The drive motor M of the feeding device is driven at a predetermined speed, after emission of the external start-signal X in order to prevent an undesired reduction of the size of a yarn store 13 by the initial consumption demand of the start-up of the weaving operation of the power loom. A signal transmitting connection 19, 19null is provided in the yarn processing system between the power loom L and a control unit C1 of the feeding device F for transmitting a start-signal X which is derived from the run-signal of the power loom. On start-up of the power loom L the drive motor M of the feeding device is driven at a predetermined speed by means of the control device and independent of the size of the yarn store in the feeding device.
摘要:
A device for monitoring the yarn reserve in weft feeders for textile looms, comprising an active element which is capable of detecting the presence of the turns of yarn that constitute the yarn reserve wound on the drum of the feeder. The device is associated with an intermediate support of its own which is pivoted to the fixed frame of the feeder and can oscillate about its own pivoting fulcrum in contrast with the action of a contrast spring in order to vary the contact pressure or inclination of the active element on, or with respect to, the drum of the feeder; the oscillation for adjusting the intermediate support of the monitoring device is produced by a downward-acting adjustment screw which acts on said support.
摘要:
A yarn feeder including a storage drum which is held in a stationary manner on a housing, a rotatable winding tube disposed between the housing and the storage drum and having an outwardly facing yarn exit, and a bracket which is rigid with the housing. An opto-electronic sensor is provided at the bracket in alignment with a light inlet/exit zone. At least one wind deflector is provided between the yarn exit and the light inlet/exit zone. The deflector protrudes outwardly beyond the light inlet/exit zone to guide an air stream emerging from yarn exit away from the light inlet/exit zone.
摘要:
A feeding device for a yarn includes a storage drum to which yarn is fed tangentially by means of a winding drive. The yarn is stored in windings on the storage drum in a yarn reserve and can be withdrawn therefrom overhead. The feeding device also includes at least one optoelectronic yarn sensing device which is arranged in a stationary manner outside the storage drum and includes a light source arrangement, a signal-generating receiver arrangement and a light guide. The light source arrangement includes a light outlet which is oriented towards the storage drum, and the receiver arrangement is oriented towards a sensing region on the storage drum. The light guide includes an inlet which is directed outwardly towards the light outlet, and an outlet which is directed outwardly towards the receiver arrangement wherein the inlet and the outlet of the light guide are arranged in positions on the storage drum which are at least axially-spaced apart.