CH411204A - Method for adjusting the length of yarn floats in a circular knitting machine, and circular knitting machine for carrying out this method - Google Patents

Description

Method for adjusting the length of yarn floats in a circular knitting jaw, and circular knitting jaw for implementing this method The present invention comprises a method for adjusting the length of yarn floats in a circular knitting jaw, and a circular knitting machine for carrying out this process. The invention can be used with advantage to adjust the lengths of yarns so that they can be carefully incorporated into the knitted fabric during the knitting operation by a continuous turning action. Such a method is particularly useful for the knitting of seamless tubular articles to incorporate neatly into the knit, without the need for subsequent refining, fleets of yarn to be reinforced or fleets between the ends of partial runs. used to shape knitting.

The method according to the invention, for regulating in a circular knitting machine the length of the waves of yarn formed between positions of the circle of needles in which a yarn is withdrawn from the needles and reintroduced on the said ones, is characterized in that that it comprises the following phases: deflection of the yarn in a swing or bend of predetermined length between the yarn reserve and the feeder for the yarn, and traction exerted on the yarn through the feeder, this traction being sufficient to seize this swinging while the feeder moves away from its feeding position. Thus, when the yarn is reintroduced onto the needles by the feeder, a yarn fleet length is determined in proportion to the quantity of yarn forming this swing. In general, one can easily arrange for the length of the float to be any length from the diameter of the needle cylinder up to any greater length desired in practice. A sufficient length of yarn may be made available in the float to be supplied to the needles along any part of the circumference of the circle of needles from about one third of the total circumference. The length of the fleet can be changed at will by varying the length of the swing formed in this fleet, as mentioned above.

In one implementation of the method, the traction exerted on the wire through the feeder to remove the dangling RTI ID="0001.0272" WI="11" HE="4" LX="1124" can advantageously be carried out by the intervention of a localized air current, preferably produced by suction; this air current serves to accumulate the free thread in a position adjacent to the hoop of needles, from where this thread can easily be introduced onto the needles. When the thread forms the slack, it may advantageously be drawn from its reserve by a tensioning device and the slack is then released to allow the draft of the localized air current on the thread to pull it through the feeder, this draft however, being insufficient to pull the yarn further through the tensioning device.

The circular knitting machine for carrying out the method is characterized in that it comprises means for forming a dangle in a yarn by deviating it from its normal path in a place located between the yarn supply and a feeder supplying the thread to the needles, means for introducing the thread supplied from said feeder to the needles and withdrawing it therefrom at appropriate times during the rotation of the needle cylinder, and means for producing a current of air located across the line of needles beyond the position of said feeder to deflect the free yarn extending from the needles into an opening located outside the circle of needles. The means for forming a slack in the yarn can be arranged so that it can be taken out of service after the slack has been formed and while the yarn is being withdrawn from the needles before being reintroduced therein. Preferably, the means for producing the air stream may be constituted by a suction nozzle connected to a vacuum source having the task of drawing air into the nozzle in the vicinity of the needle line.

The deflection of the yarn into a swing of predetermined length can be effected pneumatically, mechanically or electromagnetically, for example by means of a cylinder and piston device, a cam-operated lever or a solenoid, so as to a movable yarn guide is actuated through which the yarn passes between two fixed yarn guides and this movable yarn guide is deflected transversely to the path of the yarn.

The means for introducing the yarn can be arranged to act at varying time intervals to introduce the yarn into the needles in varying sectors of the circle of needles, and in the case of a pulsating feeder these means can be adjusted progressively by a cam such as an elastic cam for adjusting the width of the reinforcement. In this case, the slack-forming means have their movements regulated in a corresponding way so that for a greater yarn insertion length, the yarn forms a longer slack jong and vice versa.

The appended drawing shows, by way of example, two embodiments of the machine comprising the invention, as well as a variant.

fig. 1 is a general view in elevation with certain parts removed and others broken, of a first form of execution; fig. 2 is an enlarged perspective view of part of the machine of FIG. 1, view from the opposite side; fig. 3 is a larger perspective view of a suction device for yarn control; fig. 4 is a somewhat schematic perspective view of certain organs of the machine of FIG. 1, with some parts broken off; fig. 5 is a view, corresponding to fig. 1, of a second embodiment of the machine; the figs. 6 and 7 together show in perspective and on an enlarged scale a mechanism for controlling a mechanical yarn deflector used in the embodiment of FIG. 5, and fig. 8 shows in perspective at a somewhat larger scale than that of FIG. 6, a variant RTI ID="0002.0276" WI="12" HE="4" LX="304" LY="2406"> showing an electromagnetically actuated device to form a dangle in the yarn.

The machine represented in fig. 1 is a circular knitting machine of the Scott & Williams type, of conventional construction suitable for the manufacture of ladies' stockings. It comprises a base or table 10 carrying a main frame 11. The latter supports a main motor shaft 12 and a cylinder holder bench. 13. A rotatable needle roller 14 is rotatably mounted in an opening of the frame 13 and is rotated counter-clockwise (viewed from above) by a tooth wheel 15 mounted on the shaft 12. A Support 16 Carried vertically by the bench 13 supports a flap cam ring 17. Above the latter is provided the usual latch panel 18 which is hinged at its posterior part (see Fig. 1). to a Support 19, so that it can be lifted if necessary to give access to the top of the cylinder, inside the Flap Cam Ring 17. generally by 20, is supported centrally from the top of the locking ring 18 on a fixed locking plate above a rotatable flanged dial mounted inside Panel 18.

To supply the threads to the needles, the machine comprises a group of thread feeders arranged on the side of the upper part of the machine, as shown in fig. 1; One of these feeders is a reinforcement yarn feeder & sign by 21. A yarn Y passes from top to bottom through a fixed yarn guide 22 towards the reinforcement feeder 21. This feeder 21 is put into service. and off in the conventional way to allow reinforcement to be effected at different points of the bottom, and when on it is made active and inactive During each rotation of the cylinder at varying time intervals whenever partial circular reinforcement is required as is the case at the heel and the sole. The known mechanism which accomplishes this operation comprises a drive drum 23 which is rotated at desired time intervals and is provided with a segment 24 (shown to be much shorter than it actually is) capable of - able to actuate a rod 25 intended to maintain the feeder 21 in the inactive raised position for as long as necessary. A cam 26 is mounted on the main shaft 12 and RTI ID="0002.0550" WI="12" HE="4" LX="1700" LY="1910"> cooperates with a feeler mechanism to tilt a lever 27 in order to inserting and removing feeder 21 during partial circular reinforcement; the first lever 27 is carried by a sliding bar 28; a reinforcement width adjustment cam 29, integral with a ratchet wheel 30, is used to cause the bar 28 to slide in order to vary the time interval between the insertion and the withdrawal of the feeder 21. This change in tempering makes it possible to vary width of reinforcement, for example to shape the reinforcement of a cuban or a reinforced foot near the ends of the sole and the heel. lever 27 by a cleat 32. The sliding bar 28 is placed under the action of a spring 33 intended to maintain a feeler 34 which the said sliding bar carries in contact with the cam 29. The same mechanism can also actuate other devices for controlling, if desired, the operation of members of the hooking and cutting mechanism 20.

Mounted on cylinder bank 13 is a cam ring 35 which carries the cams controlling the needles and other similar cams not shown located at the main supply station which is to the left in FIG. 1, of the needle cylinder 14. The cam carrier ring 35 also carries other auxiliary cams actuating the needles and the jacks in an auxiliary station; some of these cams are shown at 36, 37 and 38. The substation cams are connected in position with a suction nozzle 39 fitted over the locking ring 18 and connected by a flexible hose 40 to a source of suction. of air. When in operation, the suction nozzle 39 produces a localized stream of air across the line of needles beyond the Feeder Position 21 so as to draw in a free length of yarn. extending transversely from the needles to the outside of the hoop of needles and sucking each loose yarn extending from the needles to the feeder 21 towards the mouth of the tuyere 39. The suction made by the tuyere holds the yarn in a position suitable to allow it to be brought to the needles under the action of the cams of the auxiliary station so that this yarn is introduced or entangled in the knit at this station. This process is described in more detail in Swiss Patent No. 373512 in the name of B.T.R. Reymes-Cole.

The nozzle 39 is constructed as a flattened tubular member (see Fig. 3) of conical shape directed inwardly from the exterior of the locking panel 18 to the vicinity of this dermer and with its greatest width. arranged 1st along the line of the Lock Panel. The flat and relatively shallow end of the nozzle forms a Suction Mouth directed towards the needles and is covered by an elongated Plate 41 which fits into a recess in Locking Panel 18 and follows the arcuate line of this last ; this Plate 41 is provided with an opening 42 of elongated shape at its end closest to the location of the yarn feeder 21 from which the yarn Y starts. From the bottom of this opening to the lower edge of the Plate 41 a slot 43 extends. On the side of this slot 43 furthest from the feeder, the lower edge of the opening 42 has a projection 44 directed upwards. Plate 41 closes off the end of tubular nozzle 39 except for opening 42 in plate 41 and a narrow space extending through RTI ID="0003.0275" WI="7" HE=" 4" LX="647" LY="2250"> along the bottom of the mouth of the nozzle 39 between the latter and the plate 41. The nozzle 39 and its closure plate 41 are shown in FIG. 3 in front of a group of needles N of the needle cylinder 14 and this figure shows how the yarn Y from the needles at YI is drawn by the suction into the nozzle 39 to form a loop L there so that the yarn becomes loose. .

The mechanism for measuring the lengths of the fleets formed between the extremities of partial paths of the reinforcing <B>EI</B> is shown in figs. 1 and 2. Mounted on a post 45 above the frame 11 is a tension rod 46 shown partially broken in FIG. 2 at its end fixed to upright 45. On said tensioning bar 46 is disposed a row of tensioning devices 47 cooperating with yarns other than the reinforcing or splicing yarn. The tension bar 46 Gate ä. its curved free end 48, by means of a Support 49, a suspended frame comprising two parallel side bars 50 and 51 held at their upper and lower ends by spacers; Lower strut is formed by a trough-shaped end of tension bracket 52. Side bars 50 and 51 have a longitudinal slider along which slider 53 can move up and down. This slider 53 is provided with a wire-guide thread 54. The slider 53 is fixed to the lower end of a piston rod 55 which carries a piston 56 capable of moving in a double-acting pneumatic cylinder 57 at the opposite ends are connected to air supply pipes 58 and 59. Thus when air is introduced through the lower pipe 59 and the upper pipe 58 functions as an exhaust pipe, the piston 56 moves up and down. and takes with it the first slider 53; conversely, when air is introduced through the upper pipe 58 and the lower pipe serves as an exhaust pipe, the slider 53 lowers to the bottom of the slide formed by the Bars 50 and 51.

The Tensioning Support 52 has at its two ends vertical wings provided with yarn-guide threads 60 and 61 between which is arranged a tensioning device 62. Thus, as seen in FIG. 2, the yarn Y coming from the reserve passes first through the yarn guide eyelet 60, then through the tension device 62 and exits through the yarn guide 61, from where it passes to the yarn guide eyelet 54 ; from this eyelet 54 the yarn Y descends to the fixed yarn guide 22 and towards the feeder 21. It is therefore clear that by raising the slider 53 a loop of determined length is formed in the fit between the tension device 62 and the feeder. 21 and the yarn forming this loop extends upward from yarn guide 61 and downward from yarn guide 54. total length of yarn desired to form a loop & The additional length of yarn taken to form the loop is withdrawn from the supply of yarn by the tension device 62. After the formation of the loop, the lowering of the slider 53 releases this loop and allows the length of wire corresponding to that which composes it to be sucked by the current of air in the suction nozzle 39 through the feeder 21 and to be kept ready to be presented to the needles of the cylinder 14 as will be explained below.

To actuate the piston 56 of the pneumatic cylinder 57, the air supply pipes 58 and 59 are connected to a control valve 70 mounted on the flap ring 17 and actuated so as to switch it alternately between two positions. opposite to draw the air alternately from the tubes 58 and 59 through a suction tube 71, and at the same time connect the unreceived tube openly to the suction tube 71. The latter can be connected to the same vacuum source. than pipe 40. Control valve 70 is actuated by control cams which rotate with needle cylinder 14 and can be conveniently mounted on the sinker bed. These cams are arranged to adjust the operation of the pneumatic piston and cylinder 56, 57 as desired. For example, one of the cams may serve to connect hose 58 to the vacuum source during the period of activity of feeder 21 immediately before it is withdrawn away from the needles and pipes 58 and 59 to release the measured loop formed by yarn Y after the feeder 21 has been taken out of knitting service and before it is lowered back to the needles.

To measure the length of the loop formed in the yarn by the movement of the slider 53, stop means determine the stroke of the upward movement of the slider by engagement with the latter. The stop means shown are adjustable so as to be able to change the length of the upward stroke of the slider 53, so that the lengths of thread drawn by the measuring device can correspond to the lengths of the partial strokes over which the reinforcement is introduced and can be progressively modified to correspond to variations in the length of said partial strokes. For this purpose, the abutment means comprise a rotary ring 63 which surrounds the bar 51 and is mounted on a support; this ring carries at regular intervals around its periphery a series of stop rods 64 of progressively different lengths intended to effect the required changes in the length of the loops formed by the yarn. Depending on the different positions of the ring 63, different of these stop rods are placed on the first path of the slider 53 and engage the latter by their ends to limit its upward movement. The ring 63 is integral with a ratchet 65 which is controlled by a pawl 66 mounted on a pawl holder 67. The latter is actuated by means of a Bowden cable 68 shaped and arranged so as to cause the door to oscillate. -ratchet During periods when splicing or reinforcement is needed. There is furthermore a further Bowden cable 69 by means of which the pawl 66 can be moved aside when it is desired to eliminate the Panel latching 63.

fig. 4 represents the means arranged to control the first cable 68 as well as to drive the cam 29 for adjusting the width of reinforcement. A toothed wheel 72, which constitutes a standard component of the machine (and which completes one revolution for four revolutions of the needle cylinder 14), carries inside its toothed crown a cam segment 74, fixed so as to adjustable by a screw 73; this Cam Segment cooperates with a feeler arm 75 Carried by a lever 76 wedged on a pin 77 Supported by bearings 78. The pin 77 Carries at its opposite end a lever 79 received by a connecting rod 80 at a pawl arm 81 at 1 the end of which is articu16 a pawl 82 engaged with the teeth of the ratchet 30 to which is fixed the cam 29 for adjusting the width of reinforcement. The ratchet 30 is mounted on a shaft 83 on which is also mounted a release plate 84 which can pivot can oscillate freely without advancing the ratchet 30. The axis 83 is supported by a fixed support 85 from which is suspended a fixed arm of support 89 fixed to a slide 90 articulated at 91 to a tail of the Release Plate 84. By actuating the Bowden cable 87, an activates and deactivates the Release Plate 84.

The cam 74 fixed to the toothed wheel 72 also cooperates with a feeler arm 92 fixed to a lever 93 which is articulated at 94 to a fixed part of the frame of the machine. The lever 93 carries a support arm 95 and a stop plate 96 fitted with an adjustable stop screw 97; everything is arranged and shaped so as to control the Bowden cable 68 whose sheath is fixed to the Support arm 95 and the central cable designated by 98 is connected by an adjustable connector 99 to a fixed Support 100 Carried by an arm 101 mounts on a fixed part of the machine frame. Lever 93 is placed under the action of a spring 102 attached between a fixed pin 103 and the Support arm 95 which tends to keep the feeler arm 92 in engagement with the RTI Segment ID="0004.0552" WI="8" HE ="4" LX="1544" LY="1739"> cam 74. It is therefore clear that at each revolution of the toothed wheel 72, the cam 29 for adjusting the width of the reinforcement will be driven in rotation on a distance equivalent to one tooth and ring 63 will also be rotated unless pawls 82 and 66 are moved apart. If it is necessary to separate the pawls, the Bowden cables 87 and 69 are actuated for this purpose at the same time by a suitable control means such as, for example, a segment which comprises the first control drum 23 or a projection of a dune. tempering chain as it normally exists in the classic machine.

It should be noted that if the gear wheel 72 rotates counter-clockwise when looking at it according to FIG. 4, actuation of feeler 92 by cam segment 74 should precede actuation of feeler 75 by said cam segment. The actuation of the feeler 92 occurs approximately one stroke before actuation of the feeler 75 to allow the measurement of the loop of yarn formed by the movement of the slider 53 of the measuring device to precede the adjustment of the width. embedding the reinforcing yarn into the knit on the next partial run over the distance the measured yarn float is to be incorporated into the knit, as will be explained later.

The operation of the mechanism described so far is as follows: Assuming that a stocking is being knitted on the machine and that the knitting has reached the beginning of the reinforced surface on which a partial circular reinforcement, the reinforcement feeder 21 is put into operation by the triggering of the free push rod 25 by the control drum segment 24. This feeder 21 is then activated and deactivated. knitting activity at each revolution of the needle cylinder 14 by means of the cam 26 which acts on the levers 31 and 27. The period during which the feeder 21 supplies yarn to the needles is determined by the position of the cam 29 width of the reinforcement This cam may remain stationary or be rotated periodically by the pawl 82 depending on whether the reinforcement surface must be of constant width or of variable width. The ring 63 of the measuring device carrying the stop rod 64 will also remain stationary or will be rotated progressively. Towards the end of each period of lowering the feeder 21 to supply the reinforcing thread to the needles, the pneumatic piston 56 of the cylinder 57 is set in motion by the suction produced by the tube 58 to cause the neck to rise. - smoother 53 and draw a loop in the yarn between the millet yarn guide 61 and the yarn guide 22, the yarn being taken from the yarn reserve by the tension device 62. The length of the loop thus formed will depend on the choice of the stop rod 64 which will be in position to stop the ascent of the slider 53 and thus limit its travel. Matters are so arranged that the amount of yarn withdrawn to make the loop by the movement of slider 53 added to the length of yarn which must in any case extend from feeder 21 to the Part of the circle of needles in which the reinforcing yarn is removed from the needles will make just the exact amount of yarn to be deposited in the knit or to be entangled in the knit across the width of the area to be reinforced in the subsequent knitting run.

Shortly after the ball of yarn was pulled by RTI ID="0005.0278" WI="3" HE="4" LX="1007" LY="2123"> the movement of slider 53, the action of piston 56 in the pneumatic cylinder 57 is reversed by applying the vacuum through the pipe 59. This action, which can advantageously take place just after the reinforcement feeder 21 has been moved away from the needles, serves to release the yarn loop. As the cylinder rotates, the reinforcing thread, from the point at which it leaves the needles, passes close to the suction nozzle and is carried away by the localized air current which rushes into the said nozzle towards 1 opening 42, so that the slack of the yarn is sucked up and a loop of yarn L is formed inside the nozzle, as shown in FIG. 3. This loop is formed by the action of the air current which draws the yarn through the reinforcement feeder 21 so as to grasp the bend which has been formed in the yarn by the movement of the ram 53, this action can be, if desired, supported by directing a current of air through the wire guide tube of the reinforcement feeder. The roller continues to rotate while the backing yarn is held taut by the loop it forms in the suction nozzle 39 and the backing feeder 21 is lowered to return the yarn Y to the needles. The reintroduction of the thread determines the length of the float and this extends from the point where the thread is withdrawn to the point where it is reintroduced, with a loop constantly maintained in the tuyere 39 to keep the thread taut. When the needles at the re-entry point have passed the mouth of the tuyere 39, they are lifted by the cams of the auxiliary station and the part of the thread float which goes to the re-entry point is supplied by the tuyere to the needles. raised which then lower to allow the yarn of the float to be introduced or knitted into the knit. The thread Y (fig. 3) passes under the projection 44 of the plate 41 and goes towards the end of the Bauche of the space comprised between the first bottom of the mouth of the tuyere and the plate 41, guiding towards the needles from the end of this space. Thus the rear end of the float is brought to the needles in a direction practically tangent to the circle of needles and is gripped by the needles which in this position have been lifted by a lifting cam.

The float of thread continues to be gripped by the needles and extracted from the same end of said space until there remains only a short length of float which extends along this space and through this space. towards the opening 42 of the bottom part closest to the feeder. The last length of float passes under projection 44 to the bottom of slot 43 and slides under Plate 41, the suction maintained through the narrow space between Plate 41 and the bottom of the nozzle mouth serving holding the thread taut against the bottom of Plate 41 until it is fully grasped by the needles.

At each subsequent revolution of the needle cylinder there occurs the same series of operations, namely formation of a float, measurement by forming a loop in the yarn before it reaches the feeder, and reintroduction of the float on the needles. When there is a change in the width of the reinforcement surface, rotation of the width adjustment cam 29 also rotates the ring 63 of the measuring device to vary the length of the loop caused by the first sliding of the slider 53. Given that the length of float obtained must be reintroduced on the needles Tors of the race in which the subsequent introduction of reinforcing thread takes place by the feeder 21, it is necessary to ensure that the first device The yarn measurement can precede backing width changes just before they occur, so that the float can be measured to match the change in width. It is for this reason that the cam sebgnent 74 is arranged so that it drives the ring 63 of the measuring device approximately one stroke before it drives the wheel 30 of the cam 29 which controls the width adjustment. .

In the embodiment represented in FIGS. 5 to 7, the measuring device is mechanically controlled. The means for forming the swing for the measuring device comprise a lever 104 hinged at 105 to a support fixed to the upright 45 and carrying a cam follower 106 at one of its ends; the other end of the lever 104 is provided with two spaced arms 107 and 108 directed downwards, provided with coaxial guide eyes <B>109</B> and <B>110</B> (fig. 6) . The cam feeler 106 cooperates with a cam <B>111</B> which constitutes a measuring cam and is pivoted at 112 on a support <B>113</B> fixed to the upright 45. The cam 111 is adjustable at the means of a Bowden cable 114 whose sheath has its upper end attached to said upright 45 and its lower end tightened in an adjustable manner in a fixed vertical arm <B>115</B> (figs. 5 and 7). The central cable of the Bowden cable 114 is designated by 116 and its lower end is attached to a support <B>118</B> fixed to the sliding bar 28 while its upper end is anchored at <B>117</ B> to cam 111. Thus, cam 111 pivots as the position of slide bar 28 is changed by backing width adjusting cam 29.

Wire guide eyelets 109 and <B>110</B> in arms 107 and 108 cooperate with two spaced wire guides similarly fixed in arms <B>119</B> and 120 directed upwards which carries a fixed support 121 and can move relative to its last wire guides so as to be in alignment or out of alignment with them. The reinforcement thread Y drawn from a reserve passes over a pigtail 122, then over a fixed thread guide 123 and over a tensioning device 124 from where it successively crosses the thread guides of the arms 119, 109, 120, 110 , after which it descends through yarn guide 22 to reinforcement feeder 21. or elbows Y@ and Y3 (fig. 5), the first RTI ID="0006.0278" WI="4" HE="4" LX="753" LY="2185"> additional thread to form res loops being extracted from the reserve by tensioning device 124.

Pulling the line in two loops or bends Y and Y3 allows relatively long lengths of float to be measured with a relatively small amplitude of the movements of the lever 104. This lever is placed under the action of a spring 125 which tends to maintain hold its feeler 106 against the edge of the cam 111, ie towards the position in which the bends Y1, and Y3 form. Lever 104 is articulated at <B>126</B> ä. a control link 127 and last link is coupled by a loss-of-stroke coupling (not shown) to actuating means such as a cam, which are arranged to keep the lever 104 normally directed towards down against the action of spring <B>125,</B> in the position shown in FIG. 6, in which the wire guides of the mobile arms 107, 108 are in the same line as the wire guides of the fixed arms 119 and 120. which rotates at the same speed as the cam 26. The timing of the cam drive is such that the link 127 is released. reinforcing thread of the needles and after a short interval of time sufficient for the formation of the bends to be complete, the rod is actuated so as to return the lever 104 to the position of FIG. 6 to release the elbows Jans 1st wire.

When a variable width reinforcement is to be carried out, the action of the reinforcement width adjustment cam 29 to regulate the stroke of the sliding bar 28 is also exerted through the intermediary of the Bowden cable 114. which adjusts the position of the cam 111; Note that the last line determines the distance the yarn guides 109 and 110 must be lifted to form the bends in the yarn and measure the length of the float. By appropriately shaping the profile of the cam 111, it is possible to correctly regulate the variation of stroke of the lever 104 which forms the bends according to the length of the periods of activity of the reinforcement feeder 21, so that a correct length of float is measured to be fed into the knit across the width of the backing surface on the subsequent partial run of the knitted backing yarn over the needles.

In a variant embodiment shown in FIG. 8, the operation of the bend forming lever 104 is controlled electromagnetically instead of mechanically. The general construction corresponds to that represented in FIGS. 5 to 7 and Wen differs only in that the mechanical control by the link 127 is eliminated and that in its place the bend-forming lever is articulated at 128 to a piston rod 129 which constitutes the frame of a electromagnetic device comprising a solenoid 130. The plunger of the solenoid is indicated by 131 and is placed under the action of a return spring 132 which tends to retain it in its lowered position. The solenoid winding is electrically supplied by wires 133 from a switch such as a miniature switch (not shown). The latter may be mounted on sinker ring 17 and actuated by a cam located on the sinker table at appropriate times during rotation of the needle cylinder to energize and energize solenoid 130. - reinforcement valve is in action and ready to be removed, solenoid 130 is energized to lift the left end of lever 104 and form elbows Y2 and Y1; in the wire in the same manner as previously described, the length of travel being determined by the contact of the feeler 106 with the edge of the cam 111. Immediately thereafter, the solenoid 130 is de-energized and its plunger is biased by the spring 132 so as to release the bends Y2 and Y2 of the thread, so that the thread is drawn forward by the reinforcement feeder 21, as previously described. Instead of the tension spring 125 there may be a compression spring 134 which reinforces the action of the return spring 132 to lower the left end of the bend lever 104 when the solenoid is de-energized.

*In the machines shown, the reinforcement is carried out by means of a pulsating yarn feeder. The process according to the invention can also be implemented in a machine in which what is usually called reinforcement by selection of the needles is carried out. In the latter case, only the bases acting normally on the needles are used, only the bases on the jacks associated with the needles which are used in conjunction with mobile cams to choose the needles which are necessary to receive or not a reinforcing thread. , the feeder for the reinforcing thread being placed in a position such that only the selected needles or the non-selected needles are at the appropriate level to receive this thread. When the knit is reinforced or has a reinforcement produced in this way, the ring 63 carrying the measuring rods 64 in FIGS. 1 to 4, or the measuring cam 111 in the construction of figs. 5 to 8, are entramds according to the variations of adjustment carried out on the needles or on the cam of selection of the jacks when it is a question of carrying out a reinforcement of variable width.

The double acting cylinder and piston device 56, 57 of FIGS. 1 to 4 may be replaced by a single acting cylinder and piston device provided with a spring or other elastic return device. Furthermore, the method can be applied to the incorporation into a tubular knit of floats other than reinforcing floats, for example floats extending between the ends of partial runs of a main yarn used in forming a tubular knit. , or fleets formed between the ends of partial runs of a reinforcing thread which is introduced in place of a main thread.

Claims (4)

CLAIM I Process for regulating, in a circular knitting machine, the length of the floats of yarn formed between positions of the circle of needles in which a yarn is withdrawn from the needles and reintroduced on the said, characterized in that it comprises the phases following steps: Flexion of the yarn into a ball of predetermined length between the yarn supply and the yarn feeder, and traction exerted on the yarn through the feeder, this traction being sufficient to grip this ball. deviates from its Feeding Position. SUB-CLAIMS 1. Process according to claim I, characterized in that the length of the float is progressively varied by varying the length of the formed ball. 2. Process according to claim 1, characterized in that the traction exerted on the yarn through the feeder to grip the ball is carried out by the action of a localized air current. 3. A method according to claim 1 and sub-claim 2, characterized in that the localized air current is produced by suction so as to accumulate the free thread in a position adjacent to the hoop of needles from which this thread can be drawn. be easily inserted on the needles. 4. A method according to claim 1 and sub-claims 2 and 3, characterized in that the yarn drawn through the feeder is accumulated in a tubular mouthpiece into which it is drawn by a localized air current. CLAIM II Circular knitting machine comprising a rotatable needle cylinder for carrying out the process according to claim I, characterized in that it comprises means for forming a ball in a yarn by deviating it from its normal path. at a place situated between the reserve of thread and a feeder supplying the thread to the needles, means for introducing the thread supplied by this feeder onto the needles and for withdrawing it therefrom at appropriate time intervals During the rotation of the cylinder needles, and means for producing a localized air current through the line of needles beyond the position of said feeder to deflect the free yarn extending from the needles into an opening located outside of the circle of needles. 5. A machine according to claim II, characterized in that it comprises means by which the means for forming the ballaut are released after formation of a ballaut and while the thread is withdrawn from the needles before its reintroduction. on said needles. 6. Machine according to claim 11, characterized in that the means for producing the localized air current are constituted by a suction nozzle connected to a vacuum source capable of sucking air into the mouth of the the nozzle in the vicinity of the needle line. 7. Machine according to claim 11 and sub-claims 5 and 6, characterized in that the means for introducing the yarn are arranged to operate at variable time intervals to introduce the yarn on the needles over seconds. - tors of the circle of needles of variable length, the means for forming the sway having their stroke adjustable in corresponding fa@on, so that for a greater length of introduction of the yarn it forms Jans the 1st yarn a more swaying Jong , and vice versa. B. Machine according to sub-claim 7, characterized in that the variable tempering of the means for introducing the yarn is carried out by means of a cam for adjusting the width of the reinforcement acting on a pulsating feeder for introducing and withdrawing the yarn. pick up the 1st wire. 9. Machine according to claim 11 and sub-claims 5 to 8, characterized in that the means for forming the swing comprises a thread guide interposed between a tensioning device and the feeder for the thread and means for move this thread guide in a direction transverse to the thread path. 10. Machine according to claim II and sub-claim 9, characterized in that the means for moving the movable thread guide consist of a pneumatic cylinder-piston device. <B>11.</B> Machine according to claim 11 and sub-claim 10, characterized in that the pneumatic cylinder-piston device is double-acting and is associated with a pneumatic control valve capable of reversing its action at appropriate times. 12. Machine according to claim II and sub-claims 10 and 11, characterized in that it comprises means for adjusting the stroke of the mobile thread guide forming the swing, these adjusting means comprising a rotary member provided with a series of stops in different positions arranged so that one of them, as desired, can be placed in the path of said mobile thread guide to determine its swing-forming movement, and means for rotating said rotary member in order to bring different stops successively on the 1st course of the thread guide. 13. Machine according to claim 11 and sub-claim 9, characterized in that the means for actuating the first yarn guide forming the swinging member comprise a lever carrying said yarn guide and a cam for oscillating this lever and moving the first thread guide and recall it to its Previous Position as and when needed. 14. Machine according to claim II and sub-claim 13, characterized in that the lever carrying the aforementioned yarn guide has a variable effective stroke and is regulated by a cam cooperating with a feeler carried by said lever, said RTI ID ="0008.0276" WI="8" HE="4" LX="1780" LY="864"> cam being adjusted according to the setting of the reinforcement width adjustment mechanism of the machine. 15. Machine according to claim <B>11</B> and sub-claim 9, characterized in that the movable yarn guide forming the swing is arranged to be controlled by an electromagnetic device for pulling and releasing. 1st dangling in 1st wire. 16. Machine according to claim II, characterized in that it comprises a suction nozzle adjacent to the circle of needles and placed outside this circle, this nozzle having a flattened shape and being provided at its mouth a Plate having a narrow gap between it and the lower part of the mouth of the tuyere, this Plate having a rounded opening at the point where the wire is to be received and a slot extending from this opening. ture to the Lower Edge of the Plate.