Patent ID: 7810397

Claim:
An apparatus for quickly and accurately measuring the capability of a primary backing mat to grip yarn forming tufts or loops of yarn in a manner that resists overshortening of tufts and snags that pull yarn in a direction that would reduce the height of one or more of the tufts or loops or that would pull one or more loops completely from the primary backing mat, any of which cause defects in the tufted interim product that if not repaired cause defects in finished tufted carpet or carpet tiles, the apparatus comprising; a) a top or generally flat surface having an opening therein to support a primary backing mat test sample and that allows a tufting needle to pass through a test sample of primary backing mat and the opening in the table top or flat surface, b) a first clamp on a first side portion of the table or flat surface to secure a test sample of primary backing mat, c) a second clamp that is movable on an opposite side of the table or flat surface for securing the test sample spaced from the first clamp, the second clamp being movable to apply a desired tension on the test sample, d) a mechanism for moving the second clamp to apply a desired tension force on the test sample, e) a movable tufting needle holder, holding a tufting needle, for moving the tufting needle in a generally perpendicular direction with respect to the first surface of the test sample to cause the tufting needle and a length of yarn to pass therethrough penetrating the first surface of the test sample, the test sample and the second surface of the test sample and to form a tuft or loop of yarn extending from the second surface of the test sample, f) a movable tuft or loop keeper for holding and moving a tuft or loop keeper into and out of a tuft or loop keeping position, g) a yarn clamp located adjacent and above the first surface of the test sample for securing an end part of the length of yarn and located sufficiently above the first surface that the yarn portion between the yarn clamp and the location where the yarn emerges through the first surface of the test sample does not contact the first surface of the test sample over a significant portion of the yarn portion, h) a force measuring device for holding the yarn clamp and for measuring continuously the force required to pull the end portion of yarn, including the tuft or loop, out of the test sample, i) a mechanism for moving the force measuring device holding the yarn clamp in a direction and manner such that the yarn clamp moves generally parallel to the first surface of the test sample and away from the tuft or loop until the loop is pulled completely out of the test sample and j) a device for recording the continuous force on the end portion of the yarn, measured by the force measuring device versus time, at least until the tuft or loop has been pulled completely out of the test sample.