摘要:
A first braking plate (32) is adapted to be coaxilly fixed to a delivery end of a drum (12). A second braking plate (40) is coaxially biased against the first one by elastic means (48) operatively engaged between the second braking plate (40) and an abutment (50). The yarn (Y) runs between the braking plates (36, 44), thereby receiving a braking action by friction depending on the pre-load of the elastic means. The abutment (50, 150) is operatively connected to a motor (54, 154), via rotary-to-translatory motion conversion means (58a, 64a, 150a, 151), for shifting in a direction such as the pre-load is varied. The motor (54, 154) is driven by a control unit (CU, CU') which modulates the pre-load in such a way as to maintain the tension of the yarn (Y) substantially constant on a desired level, on the basis of a signal generated by a tension sensor (70, 170) interacting with the yarn unwinding from the feeder.
摘要:
A braking member having a circular profile (12) is coaxially supported via elastic means at the middle of an annular support (16) connectable to a yarn feeder, and is adapted to be coaxially biased against the delivery edge of a stationary drum of the feeder for applying a braking action by friction to the yarn. The elastic means comprise at least two elongated elastic members (19), which have both their ends anchored to the annular support (16), and have intermediate portions restrainedly engaged with respective anchor projections (22) of the braking member (12).
摘要:
The yarn tension is modulated by a yarn-braking device (20) controlled by a control unit (CU) which receives signals of measured tension (T_meas) from a tension sensor (22) and compares them with a reference tension signal (T_ref) in a control loop (CL) having a proportional-integral controller (PI) generating a braking signal (BI) which minimizes the difference ( e ) between the measured tension and the reference tension. As long as the reference tension (T_ref) remains unchanged, a first set of coefficients (Kps and Kis) is used in the control loop (CL) causing the control loop (CL) 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 (Kpf and Kif) causing the control loop (CL) to have a relatively fast behaviour. The second set of coefficients (Kpf and Kif) is maintained as long as the difference ( e ) between the second value of the reference tension (T'_ref) and the measured tension (T_meas) remains greater or equal to a predetermined minimum value ( e_min ), then the system switches again to the first set of coefficients (Kps and Kis).
摘要:
The feeder comprises a stationary drum (12) on which are wound loops of yam to be fed to a downstream textile machine, and a self-governing braking device comprising a hollow, frustoconical braking member (16) which is arranged in front of the drum (12) and is supported at the middle of a spider assembly of springs (18) hooked between the braking member (16) and an annular support (19). The springs (18) have a length at rest which is equal to, or higher than, the span between their hooking point on the frustoconical member (16) and their hooking point on the annular support (19). The annular support (19) is slidably supported with respect to the drum (12) along an axial direction, under control of driving means (22), for biasing the frustoconical member (16) against said edge (12r), thereby causing the frustoconical member to align to the drum, while approaching thereto, by geometrical engagement.
摘要:
The releasable retainer comprises an adjustment screw element (23) which engages a female threaded element (22) which is rigidly coupled to a slider (18) which supports the brake support (17), and the entire adjustment system, which can move rigidly with the slider (18), is subjected to the action of at least one pair of permanent magnets (26'-26'') which are mutually opposite and whose identical poles face each other so as to repel each other in order to move the brake support (17) into a disengagement position in which the brake (15) is spaced from the drum (11) of the feeder (10).
摘要:
In a thread feed (F) with a stationary storage drum (T) having at least one cylindrical closed circumferential section (8) and a stationary annular thread control member (S) surrounding the circumferential section (8), the thread control member (S) is a finite strip (B) of uniform cross section, the facing and adjacent ends (16, 17) of which are laid on the circumferential section (8), where the strip (B) is circumferentially rigid and flexible in the radial direction of the storage drum (T) and an elastic tensioner applies the strip under elastic pre-stress at least force-fittingly to the circumferential section (8).
摘要:
A yarn feeding device (F) has a housing (1), a housing bracket (2) and a holder (5) arranged in the housing bracket for a ring-shaped yarn-tensioning body (4) that has at least one yarn-tensioning element that can be axially pressed against the feeding body. The holder (5) can slide in the bracket (2) between a yarn-tensioning position and a yarn-releasing position relative to the feeding body (3). A quick adjustment mechanism (Q) for the holder (5) that may be manually actuated by a handle (23) is provided in or on the bracket (2) and allows the holder (5) to be moved in a single stroke from the yarn-tensioning position into the yarn-releasing position without changing the set pressing force.
摘要:
In einem Fadenliefergerät mit einer Verstellvorrichtung (V) für eine Komponente (K); insbesondere für eine Fadenbremse (B) weist die Verstellvorrichtung eine drehbar gelagerte, mit der Komponente (K) gekoppelte Schraubspindel (8) und eine Dreh-handhabe (D) auf, und ist eine mit der Verstellvorrichtung gekoppelte optische Anzeigeeinrichtung (A) vorgesehen, welche eine Displayanordnung (E) mit zumindest einer logischen Zeichensequenz aufweist, die aufeinanderfolgende Inkremente der Schraubspindeldrehung repräsentiert, wobei zwischen der Displayanordnung (E) und der Schraubspindel (8) ein mechanischer oder elektrischer Schrittschaltmechanismus (M) vorgesehen ist.
摘要:
The invention concerns a thread-delivery apparatus (F) with a storage drum (1), a housing boom (6) which is rigid with the housing, and a controlled thread-draw-off brake (B) which is mounted in the housing boom (6) in an axially adjustable manner and comprises an annular brake body (8) which cooperates with a thread-draw-off region (4) of the storage drum (1) and has an outer support ring (9). The outer support ring (9) can be displaced in an annular mounting (7) of the boom (6) within an axial clearance (S) predetermined by axial counter stops (20, 21) and comprises at least one pair of sliding drives (10, 11) which act in opposite senses on the support ring (9) and are disposed on the mounting (7). According to the invention, disposed on at least one axial lateral surface (31, 32) of the support ring (9) is at least one group (2, 2') comprising a plurality of lift-adjusting ramps (2a, 2b, 2c) of different heights which can each be aligned alternatively on an axial counter stop (20, 21) facing this lateral surface.