Yarn withdrawal appratus and method

An apparatus for continuously withdrawing an advancing yarn and comprising

• a support structure,
• yarn advancing means mounted to said support structure and comprising a single rotatable roll which is adapted to be looped by the advancing yarn,
• drive means mounted to said support structure for rotating said roll at a predetermined rotational speed,
• suction means mounted to said support structure and having an inlet opening closely adjacent said yarn advancing means for withdrawing a yarn which is looped about said roll;
• and
• means defining a helical channel surrounding the roll with a small gap between the surface of the roll and said channel defining means, and with said channel defining means having an opening along its entire length which opens into said gap, a yarn inlet passage at one end of said channel defining means, and a yarn outlet passage at the other end thereof which communicates with said inlet opening of said suction means.

A method of withdrawing a freshly spun yarn from a spinneret and of threading the yarn to a rotating yarn receiving means and comprising the steps of

• engaging the yarn emerging from said spinneret by entraining the yarn in an air current,
• guiding said air current and entrained yarn so as to loop around a roll by more than 180.degree.,
• rotating said roll in the same direction as the air current is looped around said roll and at a circumferential speed at least equal to the circumferential speed of said yarn receiving means,
• tangentially withdrawing said air current and entrained yarn after being looped around the roll by means of a suction air current drawn into a suction opening which is disposed tangentially to said roll, and such that a force is exerted on the yarn emerging from said roll by means of said suction air current, and such that the yarn is looped around said roll and continuously withdrawn from said spinneret by said roll and advanced into said suction opening, and then
• threading the portion of the yarn extending between said spinneret and said roll onto said rotating yarn receiving means.

A method for withdrawing a freshly spun yarn from a spinneret and for threading the same to a rotating yarn receiving means and comprising the steps of

• engaging the yarn emerging from said spinneret by means of a suction air current being drawn into a suction opening, and so as to withdraw the yarn from said spinneret, then
• bringing the portion of said yarn between said spinneret and said suction opening into contact with a yarn delivery means comprising two rolls which are mounted in an adjacent side by side arrangement, and wherein the two rolls define rotational axes which intersect each other at an acute angle,
• rotating driving at least one of said rolls with a circumferential speed which is at least equal to the circumferential speed of said rotating yarn receiving means, and
• looping the portion of said yarn between said spinneret and said suction opening around said yarn delivery means by at least 360.degree., and then
• threading the portion of the yarn extending between said spinneret and said yarn delivery means onto said rotating yarn receiving means.

A method of withdrawing a freshly spun yarn form a spinneret and comprising the steps of

• providing a roll of conical configuration having a larger diameter end portion and a smaller diameter end portion, with said roll being mounted in cantilever fashion at the larger diameter end portion thereof,
• engaging the yarn around said roll by more than 180.degree., while rotating said roll at a circumferential speed at least equal to the yarn withdrawal speed, and including depositing the yarn onto the larger diameter end portion of said roll,
• tangentially withdrawing said yarn from the smaller diameter end portion of the roll after being looped around the roll by means of a suction air current drawing into a suction opening which is disposed tangentially to said roll, and such that a force is exerted on the yarn emerging from said roll by means of said suction air current, and such that the yarn is looped around said roll and continuously withdrawn from said spinneret by said roll and advanced into said suction opening, and then
• depositing the yarn in the form of a web or a felt.

In yarn processing apparatus having means for continuously processing and advancing a yarn along a predetermined path of travel, the combination therewith of an auxiliary yarn withdrawal means for continuously withdrawing the advancing yarn from said predetermined path of travel to facilitate yarn thread-up and the like, said yarn withdrawal means comprising

• a support structure,
• yarn advancing means mounted to said support structure and comprising two rotatable rolls, said two rolls being mounted in an adjacent side-by-side arrangement and defining rotational axes which intersect each other at an acute angle, and such that said rolls are adapted to be collectively looped by the advancing yarn,
• drive means mounted to said support structure for rotating at least one of said rolls at a predetermined rotational speed,
• a yarn waste container, and
• suction means mounted to said support structure and having an inlet opening closely adjacent said two rolls for withdrawing a yarn which is looped about said rolls and conveying the same to said yarn waste container.

In yarn processing apparatus having means for continuously processing and advancing a yarn along a predetermined path of travel, the combination therewith of an auxiliary yarn withdrawal means for continuously withdrawing the advancing yarn from said predetermined path of travel to facilitate yarn thread-up and the like, said yarn withdrawal means comprising

• a support structure,
• yarn advancing means mounted to said support structure and comprising a conical roll which is adapted to be looped by the advancing yarn, said conical roll having a large diameter end portion and a smaller diameter free end portion,
• drive means mounted to said support structure for rotating said at least one roll at a predetermined rotational speed,
• a yarn waste container,
• guide means mounted to said support structure for guiding an advancing yarn onto said large diameter end portion of said roll, and
• suction means mounted to said support structure and having an inlet opening closely adjacent said free end portion of said roll for withdrawing a yarn which is looped about said roll and conveying the same to said yarn waste container.

In yarn processing apparatus having means for continuously processing and advancing a yarn along a predetermined path of travel, the combination therewith of an auxiliary yarn withdrawal means for continuously withdrawing the advancing yarn from said predetermined path of travel to facilitate yarn thread-up and the like, said yarn withdrawal means comprising

• a support structure,
• yarn advancing means mounted to said support structure and comprising at least one rotatable roll,
• drive means mounted to said support structure for rotating said at least one roll at a predetermined rotational speed,
• a yarn waste container,
• yarn delivery guide means including a yarn guide outlet,
• yarn suction means including a yarn inlet opening for withdrawing a yarn from said yarn guide outlet and conveying the same to said yarn waste container, said inlet opening being disposed to open along a direction which is parallel to the axial direction of said one roll, and
• means mounting said yarn delivery means and said yarn suction means to said support structure so as to permit relative rotation of said yarn guide outlet and said yarn inlet opening a the circumferential direction about said one roll and between (a) a yarn catching position wherein said yarn guide outlet and said yarn inlet opening are disposed yarn guide outlet and said yarn inlet opening are disposed immediately adjacent to each other and aligned along a direction substantially parallel to the axial direction of said at least one roll, and (b) a drawing-off position, and whereby such relative rotation causes a yarn passing from said yarn guide outlet to said yarn inlet opening to be at least partially looped about said one roll.