IL30689A - Circular knitting machine with thread guide - Google Patents

Description

ss Circular knitting machine with thread guide FRANZ The invention relates to the thread guides in circular knitting particularly in circular rib knitting machines0 In known machines of this such as that disclosed for example by Patent Specification each of different threads is guided at the points in its path from the bobbin to the knitting station where it must change its direction of over thread guides which are stationary eyes or The resulting frictional resistance increases the tension in the thread between the bobbin and the knitting which in machines having conventional thread guides can amount approximately to between 6 to 12 grams Particularly in the case of wool and cotton threads or of threads composed of mixed the friction results in abrasion which causes dust to be deposited on the machine In the case of threads of fully synthetic material it has been found that such relatively high tensions in threads of the fineness customary in the circular knitting machines in question result in displacements of molecules in the individual which impair the nature of the surface and the dyeing properties of the The problem underlying the invention is to reduce the thread tension caused by the changes of direction in the thread guide of each in such a manner that practically only the tensile force which pulls the thread off the winding on the bobbin is Accordin to the invention in a circular knittin with one or more knitting stations and a thread guiding arrangement for nonelastic wherein for the purpose of limiting the thread tension between a spool of thread and the or each knitting point to the force necessary to draw the thread from spool each change of direction point for the thread arrangement is constructed as a Thread guide rollers are known in they used only for the purpose measuring thread speed or thread tension tensiometer leaflet of the firm Hans Schmidt and Schichtstrasse 8264 In circular knitting machines the friction of the threads on their thread guides is additionally disadvantageous because the friction at the various points where there is a change of direction in the various thread guides gives rise to different thread tensions and consequently to different stitch which result in an uneven stitch particularly in the case of plain fabrics und reprint from December issue 12 Authors ί Isac Rosen and Horst As this article this disadvantage is overcome by positive thread delivery which however does not eliminate the disadvantageous effect of the high tensions produced by friction between the bobbin and the thread delivery device and acting on the threads particularly on synthetic The thread guide according to the which consists only of rollers and by which a tension of at most 1 to 4 grams can be obtained produces such small differences in tension at the individual knitting stations of a circular knitting machine that the threads are pulled off the thread delivery devices such as are disclosed for example by German Patent Specification Consequently the belt feeder which customary at the present time but which is very expensive unless a gear change mechanism is can be used only one thread speed und reprint from December issue becomes superfluous as a positive delivery The stop motion one of which is provided upstream and one downstream of each thread delivery device in each thread path from the bobbin to the knitting are also equipped with thread guide In one embodiment of the invention the thread brake is also constructed as a which is positively driven without slip by the the support for the thread on the roller being for example covered with silicone Braking is e in the manner of a disc brake through the action of an adjustable spring loading a disc which is applied to one end face of the In order to prevent the tension from dropping to zero and to prevent the thread from continuing to run the event of a change of tension or when the machine it desirable to provide a thread regulating which consists of a lever the free end of which carries an eye through which the thread while its other end is connected to a spirally wound the inner end of which is fastened to a pin which is rotatable in the stationary bearing and can be secured by means of a The break stop motion senses the thread by which on rocking in consequence of a drop in tension closes a circuit which controls electronically the relay stopping the machine drive mot Only with the aid of an electronically controlled relay can the sensing lever acting to the low thread tension fulfil its An embodiment of the invention will now be described by way of example and with reference to the accompanying in Figure 1 shows the thread guide from a bobbin to a knitting Figure 2 shows the thread stop motion disposed in front of the thread delivery viewed from the Figure 3 shows the thread brake viewed from the Figure 4 shows a thread direction change roller in longitudinal Figure shows the thread device viewed from the Figure 6 shows the circuit plan of the for stopping the machine in the event of a thread break or in the event of the tension dropping to and Figure 7 shows part of a circular knitting machine having rollers and roller thread Figure 1 shows the path of a thread 1 from the bobbin 2 to the knitting station The eye 4 which regulates the thread balloon and which at the same time is a slub is disposed above the The thread path extends vertically upwards to the thread stop motion which essentially reacts to excess thread tension and in that case rocks the two thread uide rollers 6 and whic ar position shown in broken lines in Figure 2 whereby the machine is stopped electrically in a known By means of the two rollers 6 and 7 the thread is guided where it runs over the thread brake roller 9 around which it is wound at least once and which in Figure 3 is shown viewed from the The brake roller is covered on its thread support surface with a material which permits the roller to be rotated without slip by the threado This coating may for example be silicone The 9 is mounted on a shaft 10 and is secured by the collar 11 against axial displacement to the left 3 A disc 12 lies against the end face of the roller and is loaded by a spring 13 the tension of which is adjustable by means of the screw nut 14 mounted on the shaft 100 From the brake 9 the thread runs on to the thread delivery device 15 which is a delivery device delivering with in the form of a rotating at high speeds and having a smooth around which the thread is wound partly or a plurality of then running downwards to the stop which consists in known manner of three rollers 17 18 and The lever 27 6 which senses the thread 1 and which is provided with a roller 19 controls the relay illustrated in the which stops the machine drive motor by closing a circuit which through an electric resistance 28 operates a thyristor 29 for a circuit which operates the relay stopping the drive In certain instances the roller 19 may be The rollers 17 and 18 have stationary the roller 19 is movable in the direction of the moves to the left and stops the as described by electrical means On leaving the stop 16 the thread travels further downwards over the guide 20 to the knitting station 3 Figure 4 shows the guide roller in longitudinal The thread regulating device consists of a lever 22 forming the end of a spirally wound spring 21 the thread 1 running through the eye 23 on the free end said lever and being drawn by the eye slightly transversely to its direction of movement in consequence of the tension of the spring 21 This transverse force is adjustable by turning the bolt 24 on which the spring 21 is fastened by its inner end in a manner similar to the winding up or the iwinding of the main spring of a clock0 This bolt 24 is mounted rotatably in a bearing by means of a knurled disc 24 and can be secured by a screw 26 or other means 7 illustrates the path of a thread 1 running to one of the 48 knitting stations of a circular rib knitting machine The arrangement of the rollers 9 and 20 of the machine stop motions 5 and 16 and of the thread regulating device 21 22 on a stationary part of the machine is indicated only as an The individual thread stop motions and thread regulating device provided in each of the thread paths and illustrated in Figure 1 may be disposed in the sequence illustrated in Figure 1 at any suitable fixed point on the machine which is situated in the region of each of the thread pathse The bobbin 2a is the spare bobbin for the thread 1 winding off insufficientOCRQuality

Claims (2)

1. CLAIMS 1, A oircular knitting machine with one or more knitting stations and a thread guiding arrangement for nonelastic thread, wherein for the purpose of limiting the thread tension between a spool of thread and the or each knitting point to the force necessary to draw the thread from the spool each change of direction point for the thread guiding arrangement is constructed as a roller.
2. 2, A circular knitting machine according to Claim 1, wherein the thread guiding arrangement Includes a stop motion which responds to excessive thread tension and which comprises two thread guide rollers mounted on a pivoted lever. 3· A circular knitting machine according to Claim 2 with one or more knitting stations and a thread guiding arrangement for non-elastic thread, wherein the stop motion responding to ehread breakage comprises three thread guide rollers between whic!k the thread is guided. 4· A circular knitting machine according to Claim 1 or Claim 3, wherein the thread guiding arrangement includes a yarn brake which is a roller over which the thread passes in a slip-free manner and which is provided with brake means. 5· A circular knitting machine according to any one of Claims to 4, wherein a feedwheel unit is located in the thread path between the bobbin and the knitting station and effects the feed with slip* 6· A circular knitting machine according to any one of Claims 1 to 4, wherein no feedwheel unit is located in the thread path between the bobbin and the knitting station. « 30689/2 9 - 7. A circular knitting machine according to any one of the preceding claims, wherein there is furthermore provided a thread draw-off tension regulating device between said knitting point and the last roller in the thread guiding arrangement with respect to the direction of thread feed to said knitting point. 8·; A circular knitting machine according to Claim 7, wherein the thread draw-off tension regulating device comprises a lever, one end of which is provided with a thread guiding eye and the other end of which is connected to the outer end of a spiral spring, the other end of which is adjustably mounted in a stationary bearing. 9. A circular knitting machine substantially as hereinbefore described with reference to the accompanying drawing. For the Applicants DR.REINHOED COHN AND PARTNERS PC:BH