Automatic positioning device for a yarn end finder

An apparatus for preparing an end of yarn of a textile yarn package, the yarn package having a body of yarn formed on a tube, the tube having one end and an opposed end and the body of yarn having at least one tapered portion tapering inwardly from an inclined transition location toward a respective end of the tube, the yarn end preparing apparatus comprising:

• means for applying suction including a suction housing forming a suction slot through which suction is applied to a yarn package to effect drawing of a yarn end of the yarn package through the slot interiorly of the suction housing, the slot being of a narrow elongated configuration and having a lengthwise dimension at least approximately corresponding to the axial dimension of the tapered portion of the yarn package;
• means for automatically positioning the suction slot at a predetermined spacing from the tapered portion of the body of yarn of the yarn package independent of the axial position of the inclined transition location at which the tapered portion of the body of yarn tapers inwardly, the automatically positioning means including means for moving the suction housing in a guided direction in which the suction slot is moved from a start position axially beyond the respective end of the tube toward the other end of the tube to thereby narrow the spacing between the suction slot and the tapered portion of the yarn package generally parallel to the axis of the yarn package, a light beam emitting component mounted to the suction housing at an orientation for emitting a light beam along a path into the spacing between the tapered portion of the yarn package and the suction slot, a light beam detecting component mounted to the suction housing and operable to generate a stop movement signal in response to an interruption of the light beam emitted by the light beam emitting component, and control means, operatively connected to the light beam detecting component, for controlling the means for moving the suction housing to stop the guided movement of the suction housing solely in response to the receipt of a stop movement signal from the light beam detecting component, whereby the means for moving the suction housing is operable to move the suction housing from the start position to narrow the spacing between the suction slot and the tapered portion of the yarn package and the light beam detecting component is operable to generate a stop movement signal upon narrowing of the spacing between the suction slot and the tapered portion of the yarn package to an extent at which the yarn package interrupts the light beam and the controlling means is operable to stop the suction housing with the suction slot positioned at the predetermined spacing from the tapered portion of the yarn package in response to receipt of the stop movement signal form the light beam detecting component;
• and
• means for repositioning the suction slot portion after drawing in the yarn end into the suction applying means for depositing the drawn in yarn end at a predetermined location on the yarn package suitable for further processing of the yarn package at a subsequent processing station.