GB759091A - Method and apparatus for testing the wear resistance of textile yarns - Google Patents

Abstract

759,091. Testing yarns. LICENTIA TALALMANYOKAT ERTEKESITO VALLALAT. May 31, 1954, No. 16105/54. Class 120 (3). [Also in Group XIX] In testing a textile yarn for wear resistance, a test-piece is tensioned by a constant force and rotated about its longitudinal axis with a uniform angular speed so as to expose a predetermined surface area thereof to the action of a wearing tool which engages and moves along a predetermined length of the piece at a predetermined angle of rope friction, e.g. 5-10 degrees, therebetween; a valve characteristic o<SP>1</SP> the time period of the wearing action is registered until breakage of the piece occurs. In the operation of the apparatus shown, the test-piece is held between holders 10 and 11, the latter exerting tension on the yarn by means of a cord 13 attached to a floating weight 15 and is engaged by the edge 34 of a tool 33 secured to a tool-holder 24 supported by and vertically adjustable in relation to (by means of a handwheel 31 operating a screwed spindle 29 and with guide rods 25, 26, sliding in guide heads 27, 28) a carriage 21 adapted to move along guide-rods 17 and 18 on rollers. The holders 10 and 11 are rotated in the same sense and the carriage 21 reciprocated by drive mechanism operated by an electric motor 75, the supply to which is controlled by a main switch 103 and a mercury switch 104 which operates to stop the motor when the weight 15 descends thereon upon breakage of the yarn, Figs. 5 and 6 (not shown). The motor transmits a drive through a coupling, a worm shaft 67, worm gear 66 and 65, and shaft 59 to a drive-disc 58, a cam surface 56 on which co-operates with a cam roller 55 carried on a crank 54 to swing an axle 48 and thereby actuate, through double-armed levers 49 and 50 and adjustable link rods 52 and 53, levers 45 and 46 of pawl, as at 47, and ratchet wheel 41 and 42, mechanisms, which, through toothed wheels 41 and 42, and 39 and 40, rotate the holders 10 and 11 which latter, by means of a key and slot driving connection, may be axially displaced relative to 10 (by the force of the weight 15 as the yarn extends). The drivedisc 58 also operates a connecting-rod 76, linked to a buckle 78 embracing a boss 30, to reciprocate the carriage 21. The shaft 59 also drives, through worm gearing 79, a shaft 80 connected by a friction-coupling spring 84 to the driving- shaft 85 of a revolution counter 86 which is so adjusted as to indicate the number of strokes in dependence on the rotation of the disc 58 ; in addition and in order to produce a permanent graphical record of the wear-resistance qualities of the yarn, the shaft 80 drives through wormgear 95, 94, to rotate a drum 88 which feeds a tape 89 of diagram paper across which writing means 90 is moved by the axial displacement of the holder 11 amplified through an accelerating transmission gear consisting of pinions 96 and 97 of different diameters attached to a common shaft and each meshing with a rack 98, 99. Modifications may include replacement of the tool 33 by a rotating disc tangentially arranged with respect to the tast piece, unidirectional and intermittent motion of the wearing tool, and continuous rotation of the test piece.