Yarn tensioning apparatus for progressively converting a yarn from an initial essentially stress free condition to a final condition of generally uniform tension as said yarn passes upwardly from a yarn source toward yarn take-up means, said yarn tensioning apparatus comprising:
- a stanchion having at least one vertically disposed, essentially planar surface;
- first tensioning means for initially tensioning the yarn from said yarn source from the initial essentially stress free condition to a first magnitude of tension less than the magnitude of the generally uniform tension of said final condition of the yarn, said first tensioning means including:
- a single, smooth, cylindrical first friction pin rigidly and orthogonally cantilevered from a lower portion of said planar surface, a generally laterally facing arc of said first friction pin being engaged by the yarn and passage of the yarn around said first friction pin being frictionally resisted and guided thereby;
- second tensioning means for tensioning the yarn from the first magnitude of tension to a second magnitude of tension greater than the first magnitude of tension but less than the magnitude of the generally uniform tension of the final condition of the yarn, said second tensioning means including
- a single, smooth second friction pin rigidly and orthogonally cantilevered from said essentially planar surface above and laterally offset from said first friction pin in a direction away from said laterally facing arc of said first friction pin, a generally laterally facing arc of said second friction pin being engaged by the yarn and the passage of the yarn around said friction pin being frictionally resisted and guided thereby;
- third tensioning means for tensioning the yarn from the second magnitude of tension to a third magnitude of tension greater than the second magnitude of tension but less than the magnitude of the generally uniform tension of the final condition of the yarn, said third tensioning means including
- a single, smooth, cylindrical third friction pin rigidly and orthogonally cantilevered from an upper portion of said planar surface above said first friction pin, a variable, generally upwardly facing arc of said third friction pin being engaged by the yarn and the passage of the yarn over said third friction pin being frictionally resisted and guided thereby;
- arc varying means for varying the length of the arc of said third friction pin engaged by the yarn, said arc varying means including
- an elongated base rigidly and orthogonally cantilevered from a point on said essentially planar surface below said third friction pin, above said second friction pin, and laterally displaced from said third friction pin,
- an elongated planar stem pivotally connected to said elongated base parallel to the longitudinal axis of said elongated base, and
- arcuate means connected to said planar stem and forming a generally arcuate surface which extends from said connection with said planar stem over and partially around said third friction pin and the yarn engaging said third friction pin;
- and
- fourth tensioning means for tensioning the yarn from the third magnitude of tension to a fourth magnitude of tension equal to the generally uniform tension of the final condition of the yarn, said fourth tensioning means being connected to an end of said arcuate means opposite said planar stem and comprising a generally arcuate frictionally surface which is variably engaged by the yarn in passing from beneath said arcuate means, said fourth tensioning meansn being biased against the tension of the final condition of the yarn to automatically alter the arcs of contact of said yarn with said third and fourth tensioning means in response to tension variation, and said arcuate means being swingable into clamping cooperation with said third friction pin in the absence of tension in the yarn beyond said fourth tensioning means.