GB725731A - Automatic thread testing machine - Google Patents

Abstract

725,731. Testing physical qualities of materials. INSTITUT TEXTILE DE FRANCE. April 22, 1963, No. 11081/53. Class 106 (2). A machine for the continuous testing of threads comprises at least two assemblies 1, 2, 3 and 8, 9, 10 disposed one above the other, and scraper means 14, 15, 16 and guide baffles 55 so arranged that when a breakage of the thread 56 occurs, the end of the thread to be tested is guided to the lower assembly 8, 9, 10 which carries it along anew in such a manner as to attain an automatic and continuous operation of the machine. Means are also provided for measuring a physical magnitude such as the tension in or the elongation of the thread. As shown, belts 4 and 11 are spring tensioned around the rollers 2, 3 and 9, 10 respectively, the thread 56 passing between these belts and the corresponding rollers 1 and 8. The thread 56 is maintained under constant tension by causing the lower roller 8 to rotate at a slightly greater speed than the roller 1. A pivoted arm 33 is lightly biased against the thread 56 by a weight 36. If the thread 56 breaks, the weight 35 causes an extension 36 of the arm 33 to bridge two contacts 40, 41 to electrically advance by one unit a counter 37. The scrapers 14, 15, the arm 33 and the baffle 55 ensure that the broken end of the thread 56 is eventually caught between the belt 11 and the roller 8. The thread 56 is thus automatically re-tensioned and the extension 36 of the arm 33 lifted from the contacts 40, 41. Counting means for determining the length of thread dealt with and recording means for marking the distribution of breakages over the length of the thread tested may also be incorporated. The rollers 1 and 8 can be actuated separately by variable speed motors. Preferably, however, they derive their rotation from a motor 18, Fig. 2, through a variable speed gear 19 differentiating between the speeds of rotation of the rollers 1 and 8 to produce the desired tension in the thread 56. As shown, a coneshaped member 42 is driven at the speed of the upper roller 1 and a threaded spindle 44 parallel to a generatrix of the cone 42 is driven at the speed of the lower roller 8. A roller 43 threaded on the spindle 44 bears against the surface of the cone 42. In operation the roller 43 assumes progressively its position of equilibrium and indicates the stretch given to the thread 56 according to the difference in speed between the rollers 1 and 8. The tension in the thread may be tested by spring means 30 screw actuated to exert an adjustable pull through a pulley 21 mounted cantilever fashion on a bar 20 suspended on two links 22, 23 as shown. The tension in the spring is adjusted until the links 22 and 23 are vertical, the tension being indicated on a scale 32 by a finger 31. The thread 56 is normally disengaged from the pulley 21.