US3377824A - Positive yarn feeding means for circular knitting machines - Google Patents

Description

J. D. MOYER April 16, 1968 POSITIVE YARN FEEDING MEANS FOR CIRCULAR KNITTING MACHINES 2 Sheets-Sheet 1.

Filed July 27, 1966 April 16, 1968 J. D. MOYER POSITIVE YARN FEEDING MEANS FOR CIRCULAR KNITTING MACHINES 2 Sheets-Sheet 2 Filed July 27, 1966 26 0 WWW/4 w w 8 2 0 m W w 4 H w W 4 United States Patent Ofi ice 3,377,824 Patented Apr. 16, 1968 3,377,824 POSITIVE YARN FEEDING MEANS FOR CIRCULAR KNITTING MACHINES James D. Moyer, Wyomissing, Pa., assignor to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Filed July 27 1966, Ser. No. 568,191

9 Claims. (Cl. 66-132) ABSTRACT OF THE DISCLOSURE A positive yarn feed device for a circular knitting machine including a driven roller having an inflatable sleeve about which yarn is passed from a source of supply to the needles of the knitting machine. A sensing means is positioned intermediate the roller and knitting machine responsive to changes in tension in the yarn for varying the circumference of the sleeve through fluid control means to accordingly vary the rate of feed of the yarn to the needles.

The instant invention relates to yarn feeding means and particularly to such means having the capability of delivering yarn .at substantially uniform tension to another mechanism such as the stitch forming instrumentalities of a circular knitting machine.

Heretofore numerous types of yarn furnishing devices had been proposed comprising rolls and the like and serving to positively draw the yarn from a yarn supply such as a pirn at the rate determined solely by the drawing means itself and independently of variations in the drag of the yarn due to faulty winding of the pirn or other causes. In some of the prior devices provision has also been made to vary the speed at which the yarn is drawn in response to variations in the consumption of the yarn by the yarn using device such as a circular-knitting machine. The principal object of the instant invention is the provision of a positive y-arn furnishing device of the latter type but which is more responsive to changes in the demand for the yarn and otherwise exhibits advantages over the known devices. Thus an object of the invention is the provision of a yarn furnishing device by which the rate of delivery of the yarn to the yarn using mechanism is substantially instantaneously responsive to even minor changes in the tensions of the yarn such as are caused, for example, by variations in its stretch characteristics.

More particularly an object of the invention is the provision of a positive yarn feeding device comprising a rotating body around which a bight of the yarn is passed, the body being so constructed that its effective yarn drawing circumference varies proportionately with variations in the tension in the yarn being fed to the knitting instrumentalities or other yarn using mechanisms. A further object of the invention is the provision of such device in which the rotating body comprises an inflatable sleeve and there is means to subject the interior of the sleeve to more or less fluid pressure, whereby the eflective yarn drawing circumference of the sleeve increases or decreases, under the control of means for sensing the tension in the yarn and hence the demand therefor.

More specifically a device embodying the instant invention includes the inflatable sleeve interposed between the yarn supply and the knitting machine or other mechanism to which the yarn is to be delivered, the sleeve constituting a draw roll for the yarn, means to rotate the sleeve at predetermined speeds related to the speed of rotation of the knitting machine or such other mechanism, means to. apply compressed air to the interior of the sleeve to inflate the same, and valve means under the control of a yarn tension sensing device to control the fluid pressure Within the sleeve and the extent of inflation thereof and hence of its effective circumference in performing its draw roll function.

The invention will be more fully understood and fur ther objects and advantages thereof will become apparent when reference is made to the more detailed description which is to follow and to the accompanying drawings in which:

FIG. l'is an elevational view of the device of the instant invention incorporated in the yarn furnishing means of a circular knitting machine, the latter being illustrated diagrammatically;

FIG. 2 is a sectional view on an enlarged scale taken on the line 2-2 of FIG. 1 looking in the direction indicated by the arrows;

FIG. 3 is a top plan view on an enlarged scale, and with parts in section, of the device as shown in FIG. 1;

FIG. 4 is a sectional view taken on the line 44 of FIG. 3 looking in the direction indicated by the arrows;

FIG. 5 is a sectional view taken partially on the line 5-5 of FIG. 1 looking in the direction indicate-d by the arrows and illustrating diagrammatically a bight of yarn around the yarn drawing means of the instant invention and its path of travel therefrom to the knitting machine; and

FIG. 6 is a detail sectional view on an enlarged scale taken on the line 66 of FIG. 3 looking in the direction indicated by the arrows.

Referring now to the drawings and more particularly to FIG. 1 a yarn feeding device in accordance with the instant invention is illustrated at 10 in association with a circular knitting machine of the rotary cylinder type diagrammatically illustrated at 12. It will be understood that while the instant yarn feeding mechanism has found a principal field of use in connection with circular knitting machines, particularly high spced machines adapted for example, to knit .at a rate approaching one thousand courses per minute of plain knitted fabric, its use is not limited and it can be employed and its advantages obtained with other yarn using machines or devices. However t-he following description will be directed to its association with a knitting machine such as that diagrammatically illustrated.

Knitting machine 12 has the usual needle cylinder 14 and associated cam structure (not shown) whereby y-arn Y fed to the needles (not shown) through a yarn feeding means of any suitable type is converted into knitted fabric. The knitting machine also includes a yarn rack 17 having means 18 of any suitable type for supporting one or more pirns 20, one being shown, of yarn Y. The

yarn .rack additionally includes ported by one or more pillars 23, one being shown, the superstructure carrying guide eyes 24 directing the yarn from the pirn to the device now to be described.

Referring now particularly to FIGS. 2 to 6 inclusive, device 10 comprises -a tubular member or sleeve 26 having a lower threaded end 28 threaded into a socket member 30 and maintained in adjusted position therein by a lock nut 31 (see FIG. 2). Socket member 30 is rigidly secured in any suitable way to or made integral with a bracket 32 which in turn is secured in fixed rigid relationship to a member 34 forming a portion of the machine frame. The lower' end of sleeve 26 (see FIG. 2) is internally recessed as at 36 to receive a ball bearing unit 38 which rests on an annular flange 40 formedat the lower end of socket member 30. Sleeve 26 (see FIG. 2) is also provided at its upper end with an internal recess 42 supporting a ball bearing 'unit 44-. V

' An elongated tube 46 having a'central bore 47 and of smaller diameter than sleeve 26 is mounted for rotation within the latter in ball bearing units 38 and 44, tube 46 projecting above and below the tubular sleeve 26. The lower projecting end of tube 46 carries a pulley 48 suitably fixed to the tube for joint rotation therewith as by a set screw 50 penetrating an integral collar 52. Pulley 48 is adapted to be driven to rotate the tube 46 at a speed proportional to the rate of rotation of needle cylinder 14 as by a belt 54 connecting pulley 48 and a pulley 55 comprising an annular member secured to needle cylinder 14 for rotation therewith.

The end of tube 46 projecting below pulley 48 is mounted with a press fit or is otherwise secured in the inner race of a ball bearing unit 56. A hollow block houses the lower end of tube 46, hearing 56 and a sealing washer 64 of any suitable wear resistant mate-rial, such as a compressed fiber composition, on which the end of asuperstructure 22 sup-.-.

the tube rests. Set screws 66 on opposite sides of the block penetrate the same adjacent the upper end of bearing 56. The set screws are pointed as illustrated and are threaded into the block sufliciently that the inclined surfaces defined by the pointed ends press the bearing unit 56 firmly against a flange 58 formed in block 60. The block is prevented from rotating with tube 46 in any suitable way as for example by cooperating abutments on the block and frame member 34. An air passageway 68 leads from the outer annular wall of the block to the central opening of washer 64, the entrance end of the passageway being internally threaded to receive a correspondingly threaded end of a connector 69 for a conduit 70 the latter leading from any suitable source of fluid under pressure such as a compressed air source. The rate of flow of compressed air through conduit 70 is under the control of a suitable valve means such as manually operated needle valve 71.

Referring now particularly to FIGS. 1 and 2 a collar 72 is secured to sleeve 26 adjacent the upper end thereof, the collar having a projection 74 to which one leg 76 of a U-shaped bracket 78 is secured as by studs 77. An arm 80 is secured as by studs 79 to an upper leg 81 of bracket 78, the arm adjacent the end remote from the bracket being recessed as at 82 to receive a ball bearing unit 84 in which an upper end portion 88 of reduced diameter of tube 46 is mounted for rotation. A nozzle 86 projects through a central opening 83 formed in the end wall of recess 82 and is threaded or otherwise secured in the bore 47 of tube 46.

Referring now particularly to FIGS. 2, 3 and 4 a plate member 90 is fixed on arm 80 by screws 92 penetrating arcuate slots 94, a washer 96 being interposed between the head of each screw and its associated slot, whereby the angular relationship of the plate member to arm 80 may be readily adjusted. Spaced bosses 98 and 100* having opposed parallel surfaces 99 and 101, respectively, project upwardly from plate member 90, thebosses suitably being integral with the plate member. Nozzle 86 previously mentioned extends through a perforation in the plate member located between the bosses.

A valve member 102 comprising a plate having a lower flat surface is mounted for swinging movement on a horizontal pin 104, the pin being received in a bearing 106 formed in a hub portion of the valve member and the ends of the pin being secured in bosses 98 and 100. The mounting of valve member 102 is such that when its lower surface is in a substantially horizontal plane it overlies and closes or substantially closes the orifice of nozzle 86 and when swung upwardly on its pivot pin 104 opens the orifice for the emission of fluidsuchas compressed air therefrom. Valve member 102 is urged to its orifice opening position by compression spring 108.'A sensing means or tension arm 110 defining a yarn guide eye 116 has a hub portion 112 mounted for rotation with a shaft 114 the hub portion being secured'to the shaft byany suitable means such as a set screw 117. One end of shaft 114 is rotatably received in a bearing 118 in boss 98. The opposite end of shaft 114 is rotatably received in an axially extending bearing formed' in a cylindrical block 120 mounted for rotation in a cylindrical recess 122 in boss 100. A pin 124 projects inwardly from block 120 and a similar pin 126 projects outwardly from hub portion 112. A coiled torsion spring 127 (see FIG. 6) surrounds shaft 114 between block 120 and hub 112 and has one end secured to pin 124 and its other end secured to pin 126 the spring being of a character to bias hub 112 and arm 110 to rotate in a clockwise direction as viewed in FIGS. 1, 4 and 6. Block 120 may be manually rotated to adjust the bias of the spring to the desired value in any suitable way such as by employing a pin 128 fixed thereto as a handle, the block being secured in any adjusted position by tightening a set screw 130. Hub portion 112 of the tension arm carries a screw 132 threaded therein, the screw having a downwardly projecting end portion positioned to contact valve member 102 adjacent the end thereof remote from pivot pin 104. Screw 132 is adapted to be secured in any adjusted position as by a lock nut 134.

Referring again to FIGS. 1 and 2 a thread draw-off device indicated generally at 136 is mounted on tube 46 and between collar 72 and arm 80. The device comprises a cylindrical core 138 formed of any suitable material such as aluminum, a support plate 140 and an expandable sleeve 144 having an inner annular surface surrounding but in nonadhered relationship to core 138. Support plate 140 has a hub portion 146 which is secured to tube 46 for rotation therewith as by set screw 148. The peripheral surface of plate 140 is threaded to receive a correspondingly threaded annular nut 150. Sleeve 144 is made of a resilient wear resistant material such as natural or artificial rubber, neoprene or the like and has an approximately uniform wall thickness in the central section thereof the walls tapering to maximum thicknesses adjacent the ends of the sleeve. The lower end of the sleeve defines a flange 152 which is confined in fluid sealing relationship between support plate 140 and a flange 154 of nut 150. The upper end'of sleeve 144 is defined by an inwardly directed flange 156 which is confined in fluid sealing relationship between an annular shoulder 158 formed on core 138 and a nut 142 threaded on a portion 160 of reduced diameter of the core. Tube 46 at approximately the mid-point between the ends of sleeve 144 is provided with at least one pair of opposed radially extending passageways 162 com municating with bore 47 and aligned with radially extending passageways 164 in core 138 whereby fluid under pressure ,in bore 47 is conducted to the inner surface of sleeve 144. While a single diametrically opposed pair of the aligned passageways 162 and 164 have been found to be effective to inflate sleeve 144 additional correspondingly aligned passageways may be employed if desired. As mentioned above sleeve 144 is formed of rubber, neoprene or like stretchable resilient material, such material having the advantage, in addition to those due to its stretchable resilient properties, of providing a nonslipping surface for a yarn drawn in a :bight therearound as illustrated in FIG.

whereby upon each rotation of the sleeve a predeter-- mined length of yarn is drawn from the pirn irrespective of variations in tension of the yarn between the sleeve and the pirn caused by imperfections in the winding of the pirn or the like.

Base 166 of U-shaped bracket 78 support arms 168 and 170 at a height corresponding to the mid-point of the length of sleeve 144. Each of the arms 168 and 170 at their ends toward roll 136 carries a yarn guide eye 172. Arms 168 and 170 are secured to base member 166 as by screws 174 penetrating elongated slots in the arms and threaded into the base member whereby the distance of the guide eyes from core 138 may be adjusted. An arm 176 is secured to rack 17, the arm defining a guide eye 178 in the path of the yarn lbetween guide eye 116 of tension arm 110 and the yarn feeding means of the knitting machine.

In preparation for the operation of the knitting machine incorporating the positive yarn feeding means of the instant invention the yarn leading from pirn is threaded through guide eyes 24 then through guide eye 172 of arm 168 in a bight around sleeve 144 thence through guide eye 172 of arm 170. through guide'eye 116 of tension arm 110 and finally through guide eye 178 to the yar feeding means of the knitting machine.

The tension to be exerted by the tension arm on the yarn will vary with the type of yarn. For example for nylon yarn of from fifteen to seventy denier the resistance of the tension arm to movement should be such that approximately a one gram pull is required at the guide eye 116 to rotate the arm against the action of the spring. Hence the torsion of spring 127 is adjusted to the desired value, as determined by the particular yarn employed, by rotating block 120 and securing the block in its properly rotated position by set screw 130. Plate member 90 is then adjusted to position the guide eye 116 of tension arm 110 in the vertical plane of the travel of the yarn between guide eye 172 of arm 170 and guide eye 178.

Following the above described adjustments the tension arm is manually depressed to cause screw 132 to hold valve member 102 closed against the orifice of nozzle 86, valve 71 is partially opened to admit fluid, suitably air, under pressure to the bore 47 of tube 46 and the knitting machine is operated. The tension arm is then released and valve 71 adjusted until the extent of inflation of sleeve 144 is such that it is delivering the yarn at the rate demanded by the knitting instrumentalities of the machine with the tension arm in an intermediate position partially releasing, through the medium of valve member 102, the fluid pressure within the sleeve. Thereafter as the machine continues to operate, the sleeve, due to its nonslip surface characteristics, positively delivers a given length of yarn on each rotation. Furthermore any change in the demand for the yarn by the knitting instrumentalities and any change in the length of the yarn between the sleeve and the knitting instrumentalities resulting from the normal variation in the stretch characteristics of the yarn, both of which cause variations in the tension of the yarn, are substantially instantaneously compensated for by the adjustment of the degree of opening of valve member 102 and hence of the degree of inflation of sleeve 144 and the length of its yarn drawing circumference,

The device of the instant invention, as described above, thus provides not only for positive withdrawal of the yarn from the supply at a predetermined rate, which is not influenced by faulty winding of the supply pirn or other such faults, but also for substantially instantaneous response to the change of tension in the yarn as it is fed to the knitting instrumentalities. As a result a fabric of uniform stitch structure is produced.

Having thus described the invention in rather full detail, it will be understood that these details need not be strictly adhered to and that various changes and modifications may be made all falling within the scope of the invention as defined by the swbjoined claims.

What is claimed is:

1. A device for positively delivering yarn from a supply thereof to a yarn using apparatus comprising a rotatable body having an annularly continuous yarn engaging surface, means for rotating said body, means for guiding yarn from said supply around said yarn engaging surface and to said yarn using apparatus, means engageable with said yarn between said body and said apparatus for sensing the tension in the yarn, and means under the control of said sensing means for varying the circumferential extent of said yarn engaging surface.

2. A device as defined in claim 1 wherein said rotatable body comprises an inflatable element having an inner wall and said means for varying the circumferential extent of said yarn engaging surface comprises means for applying various fluid pressures to the inner wall of said inflatable element to inflate the same to different extents.

3. A device as defined in claim 2 wherein said means for applying various fluid pressures to the inner wall of said inflatable element comprises means defining a fluid passageway having an entrance and an exit, means for supplying fluid to said passageway through said entrance, valve means at said exit for controlling the flow of fluid therethrough, and means intermediate said entrance and exit for conducting fluid from said passageway to said inner wall of said inflatable element.

4. A device as defined in claim 3 wherein said means under the control of said sensing means comprises means for controlling the extent of opening of said valve means.

5. A device as defined in claim 1 and comprising a tube having a bore therein and wherein said body comprises a core surrounding and secured to said tube, an inflatable sleeve defining said yarn engaging surface and having an inner surface surrounding said core, said sleeve being sealed at the ends thereof, and wherein passageways are provided leading from the bore of said tube through the wall thereof and through said core to the inner surface of said sleeve and wherein said means under the control of said sensing means comprises means for supplying fluid under pressure to said bore and passageways and means controlling the flow of fluid therethrough.

6. A device as defined in claim 5 wherein said means controlling the flow of fluid through said bore and passageways comprises an exit orifice from said bore, a valve member movable between positions in which it closes and opens said exit orifice and wherein said sensing means comprises an arm under the control of the tension of the yarn between said device and said apparatus, said arm being mounted for swinging movement and including means to adjust said valve toward orifice closing position upon increase of the tension of said yarn.

7. A device for positively delivering yarn from a supply thereof to the knitting instrumentalities of a circular knitting machine having a rotary needle cylinder, a rotatable body comprising an inflatable sleeve having an annular yarn engaging surface, means for rotating said body in timed relationship to the rotation of said needle cylinder, means for guiding yarn from said supply around said yarn engaging surface and to said knitting instrumentalities, means engageable with said yarn between said body and said knitting instrumentalities for sensing the tension in the yarn, and means under the control of said sensing means comprising means for applying fluid under varying pressures to the interior surface of said sleeve for varying the circumference thereof at said annular yarn engaging surface.

8. A device as defined in claim 7 wherein said rotatable body additionally comprises a core which said sleeve surrounds, and said means for rotating said body comprises a tube axially penetrating said core and secured thereto, and said means for applying fluid under varying pressure to the interior of said sleeve comprises a supply of fluid under pressure connected to the interior of said tube and passageways leading from the tube to the interior surface of said sleeve.

9. A device as defined in claim 7 wherein said means under the control of said sensing means comprising means for applying'fluid under varying pressure to the interior surface of said sleeve comprises a source of fluid under pressure, a passageway leading from said source to the interior surface of said sleeve, and valve means under the control of said sensing means for varying the fluid pressure within said passageway.

I References Cited UNITED STATES PATENTS OTHER REFERENCES B 26081 VII/54b, Aug. 23, 1956, German printed application, Janssen.

ROBERT R. MACKEY, Primary Examiner.

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