Patent GB-464202-A (GB)
Title: Improvements relating to yarn testing machines
IPC: G01N3/08
Filed: 1936-11-30
Abstract: 464,202. Testing strength and extensibility of yarn. PAGNACCO, A. Nov. 30, 1936, No. 32744. Convention date, Nov. 30, 1935. [Class 106 (ii)] In a yarn - testing machine in which thread lengths are brought successivelyandautomatically into the clamps of a straining device and mean strength values automatically recorded, a distributer provided to carry the ends of the threads from a plurality of bobbins is controlled by the machine drive so that the ends of the threads are brought one after another within the range of the introducing member after a predetermined number of tests on each thread. General Operation. When the main switch 71 is made, the motor P is started and a clutch 43 operated by a solenoid M is thrown into engagement with the drive which rocks a shaft 44 carrying arms 45 through a half turn. At the ends the arms carry spring disc grips 46 for the thread. The thread ends from several bobbins are brought to a distributer 56 of segmental shape pivoting about a shaft 56<1> and formed with ratchet teeth 57 at the lower end and with a wooden segment 58 at the upper end. The latter has an eyelet 59 and small spring grip 60 for each bobbin, the end of the thread being passed through the eye and into the grip 60. The arm 45 lies under the distributer and. on rocking engages the thread end in grip 46 and carries it forward. The main spring testing grips 1, 1a are opened by wedges 49b on levers 49 which are rocked by a roller 48 engaging a circular cam groove 471 in a cam plate 47 on the shaft 44 the groove having two recesses at opposite ends of a diameter. The arm 45 advancing lays the thread in grip 1 and carries it over a feeler 30 on a pivoted mercury switch 31 and into the grip 1a. The depression of the switch 31 makes the circuit of a solenoid N to operate clutch 28 for the tension applying means, the arm moving switch 64 or 65 to declutch its drive. Tensile straining device. This comprises a parallelogram linkage 21, 22, 23, 24 of which link 21 carries the switch 31 and grip 1a. The linkage is rocked by a reduction drive 29, 27 through clutch 28. Recording stress. The grip 1 is connected by sliding rod 2 and chain 3 to a sector 4 on shaft 5 which carries an arm 7 and pendulum 6. Pawls 9, 10 carried at each side of the arm engage respectively a toothed quadrant 12 and toothed wheel 16 loose on shaft 5. As the shaft is turned, the pendulum 6 is raised and when the thread breaks, the pendulum returns to zero, the pawls 9, 10 rotating the quadrant 12 and wheel 16 to the extent of movement of the pendulum. A quadrant 13 in one with the member 12 gears with a quadrant 14 on a lever 15 and thus raises the pen T1. The wheel 16 is geared by a reduction gearing with a similar quadrant and gear connected to a pen T2. This quadrant is engaged by a friction brake and thus with the wheel 16 is held in the position reached. A fixed pin 11 disengages pawl 9 in the zero position. The reduction gearing is nÎm times slower than the shaft 5 where n is the number of spools and m the number of tests on each spool. The pen T1 shows maximum and minimum stresses whereas the pen T2 has successive tests added to it in the reduced ratio and shows the average of all tests. Control. A wheel Z has as many notches on its periphery as there are bobbins, for instance seven, and is advanced by a pawl-andratchet gear from rod 41a a seventieth of a turn at each test. At the tenth test, a notch tilts switch 66 and closes momentarily a circuit of an electromagnet S to allow quadrant distributer 56 to move so that the thread end of the next bobbin is over part 46. When successive bobbins have been presented to the part 46 and the complete seventy tests made, a pin y on disc z tilts a switch 68 to make the circuit of a solenoid R which releases the friction brake and allows the wheel 16 to return to zero under the influence of the weights of quadrants &c. Recording strain. A third pen T3 is connected to one end of a lever 32, the other end of which is connected to a flexible member which passes around a pulley 34 carried by a lever 35 and is attached to a pulley 36 on shaft 5. A second flexible member 37 fixed at 38 passes around a similar pulley on the axis of the pulley 34 and is fixed to a quadrant 40 connected by bell-crank 41 and rod 41a to link 22. The proportions of parts are so chosen that as long as the length between grips 1, 1a is constant no relative movement occurs between members 33, 37, but on strain occurring, the lever 32 is tilted to move pen T3.