Abstract: At least one circular ridge, which projects upwardly beyond the surface of the navel of the thread delivery device, is placed in the path of yarn being removed from the peripheral wall of the spinning chamber and delivered to the throat of the navel. The ridge has a height of at least 0.003" and is radially so located in proximity to the edge of the navel that the yarn being formed and lifted from the wall of the spinning chamber first engages the navel at the ridge.

Abstract: At least one circular ridge, which projects upwardly beyond the surface of the navel of the thread delivery device, is placed in the path of yarn being removed from the peripheral wall of the spinning chamber and delivered to the throat of the navel. The ridge has a height of at least. 003" and is radially so located in proximity to the edge of the navel that the yarn being formed and lifted from the wall of the spinning chamber first engages the navel at the ridge. The result of the engagement of the yarn with the ridge is that the twist is reduced and a higher break strength is achieved with a reduction in imperfections.

Abstract: At least one circular ridge, which projects upwardly beyond the surface of the navel of the thread delivery device, is placed in the path of yarn being removed from the peripheral wall of the spinning chamber and delivered to the throat of the navel. The ridge has a height of at least 0.003" and is radially so located in proximity to the edge of the navel that the yarn being formed and lifted from the wall of the spinning chamber first engages the navel at the ridge. The result of the engagement of the yarn with the ridge is that the twist is reduced and a higher break strength is achieved with a reduction in imperfections.

Abstract: An improved navel member positioned in the cover of the spinning rotor of an open-end spinning frame includes a barrel having a longitudinal passageway extending therethrough. The axis of the passageway is substantially coincident with the thread path as it exits the spinning rotor. A cylindrical insert is fixed in the barrel passageway and includes a longitudinal channel therethrough through which the thread actually passes. A plurality of spaced longitudinal grooves in the inside wall surrounding the longitudinal channel receive elongated ceramic rods partially embedded therein. The rods form a plurality of spaced obstructions around the periphery of the longitudinal channel. The periphery of yarn passing through the navel member intermittently engages and disengages the ceramic rods causing an improved roughening and bulking effect.