MEJORAS EN LOS RODILLOS DE AVANCE PARA MAQUINAS DE RETORCER HACIA ARRIBA, ESPECIALMENTE PARA MAQUINAS DE DOBLE TORSION DE HILO

摘要

A thread-advancing roller, which will allow for changes in tension as a thread is wound by a reciprocating laying-guide, comprises thread-clamping means which form part of a thread-groove and which are reciprocable to narrow the groove under the control of means which operate automatically between the point of entry and the point of departure of the thread. In the forms described, (a) the groove is formed between two cylinders fast on a driving shaft with flared inner faces. The base of the groove is formed by pins interconnecting the two cylinders. One of the cylinders houses a series of magnets of which those on the outer sector occupied by the thread are forced by the repulsion of a fixed magnet toward corresponding damping faces on the other cylinder Fig. 1 not shown. (b) One of the cylinders is fixed and carries pins projecting into recesses in the other cylinder on which members can slide towards and away from the clamping members under the repulsive and attractive influence respectively of magnets on the rotatable cylinder, Fig. 8, (not shown). (c) The movable magnets may be replaced by members attracted in the thread area by a fixed magnet or moved by a cam Figs. 7, 18, (not shown). (d) The movable magnets are replaced by hinged two-armed members which are rocked in the thread area as they come under the influence of a fixed magnet; the hinged members may be so arranged relatively to the corresponding clamping-members that the thread follows an undulating path, Fig. 4, (not shown). (e) One of the cylinders may be formed as a plate with recesses which co-operate to grip the thread with balls or pins which are held magnetically out of engagement with the recesses except in the thread-area where they are moved magnetically to engage the recesses. Figs. 9, 10 (not shown). (f) One of the cylinders is formed as a plate able to rock, in the thread area, towards the other cylinder under the influence of a cam or a magnet, the cylinder and plate being formed with teeth to grip the thread and cause it to follow an undulatory path, Figs. 11, 14, 17, (not shown). (g) Two members having alternate protruberences and recesses are mounted in the cylinders and are urged towards one another by springs or pneumatic means; the members are kept separate from one another except in the thread-area by a wheel between them, Figs. 15, 16, (not shown).