US3073139A - Controlled feed mechanism for yarn - Google Patents

Description

Jan. 15, 1963 H. G. PosT ETAL 3,073,139

coNTRoLLED FEED MECHANISM FOR YARN Filed May 2s, 1960 F/G. l.

/N VEN TORS A TTORNE Y United States Patent() L 3,073,139 CONTROLLED FEED MECHANISM FOR YARN Herbert G. Post, 5792 Crescent Ave., Buena Park, Calif., and'William L. Carroll, 328 N. Newlin, Whittier, Calif. Filed May 23, 1960, Ser. No. 30,918 6 Claims. (Cl. 66-132) This invention relates to an improved controlled feed mechanism for yarn and has -for one of its principal objects the provision of a device of the class described, which will automatically maintain a predetermined tension on a strand of yarn which is being fed off a bobbin to a knitting machine or the like.

- One of the important objects of this invention is to provide a-method and apparatus for feeding strands of yarn or thread, which are more or less elastic, at a uniform tension to the needles of a knitting machine or similar apparatus.- Another object of the invention is to provide a new and improved yarn feeding mechanism which will automatically vary the rate of feed of the yarn in accordance with the demand therefor by the knitting machine itself.

Another and still further important object of the invention relates to the provision of a yarn tensioning device which will automatically feed the strands under uniform tensionirrespective o f the speed at which the yarn being'f'edis'taken up. l f. Yet another object ofthe-invention resideslin; theprlo'- visionof-a simpleyyet effective, means vvfor automatically controlling and equalizing the tension on a plurality of strands of yarn or similar materials which arebeing fed into a processing machine, whereby undesirable and unsightly imperfections in the final product are avoided. 1 Other and further important objects of the invention will be apparent from the disclosures in the accompanying drawings and following specification. The invention, in a preferred form, is illustrated in the drawings and hereinafter more fully described,

In the drawings:

FIGURE 1 is an illustration, somewhat diagrammatic,

iof the essential parts of the-strand feed controlling .mechanism of this invention.

FIGURE'Z is'an enlarged detail view, taken on the 'plane of the line 2-2 of FIGURE 1, looking in the direction indicated by the arrows.

FIGURE. 3 is an enlarged detail sectional view on the -line 3-3 of FIGURE l, looking in the direction indi cated, and with certain parts broken away.

-' t FIGURE 4 is a wiring diagram illustrating the action of two of the`automatic yarn tension control devices of The yarn 16 is preliminarily passed through an eyelet for guide 18 in asupport 20 and then to a conventional .tensioning device 22. These elements are all mounted on the frame 10 in any desired or convenient manner.

ing apparatus of this invention. A 'stand 12 is provided `to support a bobbinv14 of yarn 1,6. if

'A lmotor 24 is mounted beneath the frame 10, and the shaft of this motorv drives a yarn feed wheel 26. This feed wheel contacts a juxtaposed wheel 28 (FIGURE 2) supported by a suitable bracket or the like'30 from the correspondingly rounded to fit in the groove of the wheel 52S' and thereby 'provide a'non-slippingrgrip upon the.;

frame 10, and any .suitable means is providedfor main-i strand 16 .which is being fed between the wheels whenever the motor 24 is turning.

From an inspection of FIGURE 4, it will be evident that a plurality of motors 24 is employed in one complete knitting mechanism, and these are usually arranged in a circle about the knitting machine, whereby a suitable satisfactory feeding of the numerous strands of yarn is effected, and without any possibility of slippage at the feed wheels.

A bracket 32, fastened to the underside of the frame 10, supports an eyelet or guide 34 through which the strand 16 is possed, and another guide 36 is mounted on the end of an adjustable arm 38 pivoted at 40 to a supoprt 42 which is an extension of the bracket 32 (FIGURE 3).

A permanent magnet 44 is on the end of the arm 38, and this is mounted in juxtaposition with a tiltable mercury switch 46 also on the bracket 32. The tiltable portion of the mercury switch is indicated schematically by the switch blade 45.

The switch is normally open, and a pair of wires 50 leads from the switch to a resistor or other motor speed control element 52, as best shown in FIGURE 4.

From the guidel or eyelet 36, the strand 16 is then led either directly to the needle bedl54 vor through an addi- 'tionalguide, if s uch becomesnecessary; j, i. The mercury switch 46 is either in-or ,attached toa soft iron housing, not' shown-whereby counter-clockwise movement of the-magnet 4 4 from'thefpos'ition illustrated in FIG. 4 toja positinimmediately adjacent theA switch 46 will tilt the switch, causing the same to close, thereby momentarilyspeeding up the motor 24, which is of the direct current type for this purpose. v

in operation, each and every one of the plurality of motors 24, which form part ofthe complete'mechanism, is preliminarily-set for a predetermined speed by means of a mastercontrt, as indicated more'or less diagrammatically aty60 in FIGURE 4 and which is part of the circuit which' controls all the motors'and includes the respective mercury switches.

Yarns 16 from the numerous bobbins 14 are then brought through 18 tol the'conventional tensioners 22 "and then to the respective yarn feed'wheels 26-28 and finally through the guides 34 and 36 tothe needle bed 54. All of the motors 24 are then synchronized to operate at the same speed of any desired or necessary revolutions per minute, thereby causing each and every oneof the fof strands 16 is not being fed at a sufficient rate of speed to supply the demands of its respective needle, the slightest=pull resulting from this inc reased tension will tilt the arm 38 about its anti-friction bearing pivot 40, causin'g the magnet 44 to shift its position sufficiently to close the mercuryy switch 46. This actuatesthe resistor 52`to vimmediatelyfeed an increased supply of current to that particular motor 24, speeding up the-same to a suicient degree to release the excess tension on the related strand 16 whereupon the magnet 4 4 will move back into its Yoriginal position, opening the switch 46 and accordingly moving the resistor 52 back to its original position, again reducing the motor speed to its original pre-set 'revolutions per minute and again presenting a normal feed speed.

The switch 46-need not be of the mercury type, as other switches with proper environmental operating means will perform satisfactorily. "One type of mercury switch has a soft iron core built into its glass housing and this operates very satisfactorily. The element 60 comprises a rheostat, and this is employed to preliminarily adjust the feedl motors 24 to'aspeed just below the amens take-up speed at the needle bed 54, and this is done in combination'with the adjustable resistor 52 and with thewnlagnetically operated switch 46 in open position.

rlfhe operator -then checks to ascertain that the speed of the feed motor 'or motors 24 is above needle take-up speed when the switch 46 is closed. Closing of this switch shorts out the`r'esistor 52 and accordingly'raises the speedr of that particular inter-connected feed motor; "lhe feed fnoto'r fields may be separately excited for better regulation.

When Ithe main motor or take-up is energized, the feed motors also start', and at this point, .a slight over-feed of yarn or strand is initiated, rboth on the start or stop of the main motor. Then when, for any`reason, the length of the yarn 16 is decreased'between Ithe feed wheels and the needle bed, the switch 46 is immediately actuated, causing a slight over-feed of that yparticular strand of yarn by increasing the speed of that individual motor 24. This slight over-feed-continues until the tension on the yarn is lessened to4 a degree allowing the outer end 36 of the 'pivoted arm $8 tonrisefopening the switch 46 and permitting the motor 24 rto accordingly run at a slightly slower speed because of passage of current through resistor 52 This action of alternate over-feeding and underfeeding is'c'ontinued so long .as the main motor or take-up continues to operate.l i'

It will be evident that herein is provided a simple, yet efficient? apparatus and method of feeding and controlling yarn or similar mateialin the textile industry and which automatically overcome all variablesoriginating at the .source of supply, sufc'h as a bobbin, 'and which -will further vthen automatically deliver said Ayarnor other inaterial tQ"a" tak'e-up'or .similar Iapparatus at a controlled rate no tension and regardless of the rate of delivery required by the take-up' or similar equipment. i

This will improve the quality of the final product, decrease undesirable stoppages, render maintenance more easy, facilitate .rapid `and vaccurate set-ups and changeovers and will generally increase over-all efficiency.

Qne of the real problems now existing in this industry has not been solved because ofthe lack of a suitable apparatus and method which .this invention provides. Presentday`m'ethods'allow thetake-up or other apparatus to pull the yarn or other material directly from the source and usually through various tensioning and compensating devices in an eifort to vutilize` variables at the source. Some of these variablesare caused under-winding, improper packaging', knotsl and variances in the distance from the sottrae to the Vtake-'up `Present feeding vmechanisms de- Vcrease the .variables but" do not eliminate them entirely `because the compensators employed willV not and cannot synchronize a multiple of "strands between the plurality of sources and single take-up mechanism, particularly over any extended periodof'time, These compensating meth- 'ods' attempt `to regulate Vthe amount of material entering the take-up byphysicallyrnoving the position of the strand or by overffeeding or unde,1i-feeding.Y Such methods which allow the take-up to move the compensator' before it can assure a proper feeding will induce a variable in the strand, whiilhrwillinevitably appear in the finished prodnot way ofy imperfections, and themainV reason for this deiicienc-y is slow reaction time in the various compen- ,Stoors now enrloyedl The apparatus of this invention will minutely and alternatvely over-feed and under-feed the yarn or other material to the take-up or other apparatus, as required, so there is never any appreciable change in the effective length of the strand beingl fed. The method and apparatus of this invention assures that any changes in strand length are always at l an absolute vpredetermined minimum, and

these will never change, regardless of any variables at the source -or at the take-up.V The` monitoring device of this invention which, when once preliminarily adjusted and calibrated, jwill'subsequently react immediately and properly determine overt-feedandnndeI-feed.

The feed Wheels 26 and 28 are controlled and tuned very minutely, slightly under the natural demand of the take-up or other apparatus, whereby only a very small increase of speed by way of a fine tolerance is required for only a very short space of time. This is accomplished by the very low friction pivot 40 for .the magnet arm 38 which activates the switch 46 through magnetic lines of flux and the complete absence of any mechanical connection.

Accordingly this invention presents an automatic control for the relatively high speed at which most circular knitting machines operate and will correspondingly increase the rate of feed of the yarn Whenever the tension on any particular strand increases above optimum operatingrelationship. Also, as soon as the tension is lessened,- the particular motorwill be automatically returned to normal operating speed, which is equal yto the demand of the take-up means while maintaining the yarn under uniform tension, although the demandmay considerably vary the rate of travel of the yarn itself. v This'particular device can'be readily adapted for use with various types orf knitting machines, even though the same varyviny speed requirementsvover a relatively wide range. The unit is obviously of very light construction and extremely sensitive to even the slightest variations in tension so that a uniform supply of ya'rn is fed to the knitting machine itself at all times and a much better final product will inevitably result. We are aware that many changes may be made and numerous details of construction varied throughout a wide range without departing from the. principles of this invention; and we', therefore, do not'p'ropcse limiting the patent granted hereon otherwise than as necessitated bythe prior art.

We claim as our invention:

l. In a devicefo'r controlling the feed tension of a strand of yarn at the needle bed of a knitting machine, the combination of: a pair of yarn feding Wheels; a motor for driving said yarn feeding wheels; guide means for a strand of y-arn interposed between said feeding wheels and said needle bed, said guide means including a pivoted arm supporting one of said'guide means and mounted for pivotal movement in response to changesin yarn tension at said needlebed;l anv electrical control circuit for said motor actu'atable by said pivoted arm, said control circuit including a normally o-pen magentically energized switch operable by said lpivoted arm; vand a resistor adapted to be shorted by said switch to momentarily increasev the speed of said motor when said pivoted arm is deflected to energize saidimagnetio switch. i

2. In a device for controlling the feed tension of a strand of yarn at the needle bedof a knitting machine, the combination of: yarn feeding means; a motor for driving said yarn feeding means; guide' means for a strand of yarn interposed between said feeding means.. and said needle bed, said guide means including a pivoted arm supporting one of said guide means and mounted for pivotal movement in response to charges in yarn tension at said needle bed; an electrical control circuit forsaid motor actuatable by said pivoted arm, said lcontrol circuit including a normally open magneticallyenergized switch operable hy said pivoted armi; and a resistorv adapted to ybe shorted by said switch to momentarily increase the speed of said motor when said pivoted arm is deflected to energize said magnetic switch.

3. In a device for controlling the feed tension of a strand of y-arn at the needle lbed of a knitting machine, the combination of: yarn feeding means; a motorconnected to'said yarn feeding means `for drivingfthe same; guide means interposedbetween said yarn feeding-means vand saidneedle bed, said guide means includingy an Yelongated pivoted arm having a ,portion engaging said yarn motor and said pivoted arm, said electrical control circuit including a rheostat for initially setting the speed of rotation of, said motor, a normally open magnetic switch operable by said pivoted arm and a resistor connected in said circnit and adapted to be shorted out when said switch is closed by the action of said pivoted arm.

4. in a device for controlling the feed tension of a strand of yarn at the needle bed of a knitting machine, the combination of: a pair of yarn feeding wheels; a motor connected to said yarn feeding wheels for driving the same; guide means interposed between said yarn feeding wheels and said knitting machine, said guide means including an elongated pivoted arm having a portion engaging said yarn strand, said portion being mounted for pivotal movement in response to changes in yarn tension at said needle bed; and an electric control circuit interposed between said motor and said pivoted arm, said electrical control circuit including a rheostat for initially setting the speed of rotation of said motor, a normally open magnetic switch operable by said pivoted arm and a resistor connected in said circuit and adapted to be shorted out when said switch is closed by the action ot Said pivoted arm.

5. In a device for controlling the tension of a strand of yarn at the necdie bed of Ia knitting machine, the combination of: positive feeding means engageable with said strand; a motor connected to said positive feeding means to drive the same; movable guide means engageable with said strand and mounted for movement in response to changes in yarn tension at said needle bed; and an electrical control circuit interposed between said motor and actuable by said movable guide means, said electrical control circuit including a normally open switch actuatahie by said movable guide means and motor speed control means in said circuit adapted to be operated by said switch to alter the speed of said motor when said switch is closed by said movable guide means.

6. In a device for controlling the Vtension of a strand of yarn at the needle bed of a knitting machine, the com bination of: positive feeding means engageable with said strand; `a motor connected to said positive feeding means to drive the same; movable guide means engageable with said strand and mounted for movement in response to changes in yarn tension at said needle bed; and an elec- References Cited in the le of this patent UNITED STATES PATENTS 2,248,88l Lawson July 8, 1941 2,810,936 Altenburger Oct. 29, 1957 2,949,757 Page Aug. 23, i960

Claims (1)

1. IN A DEVICE FOR CONTROLLING THE FEED TENSION OF A STRAND OF YARN AT THE NEEDLE BED OF A KNITTING MACHINE, THE COMBINATION OF: A PAIR OF YARN FEDING WHEELS; A MOTOR FOR DRIVING SAID YARN FEEDING WHEELS; GUIDE MEANS FOR A STRAND OF YARN INTERPOSED BETWEEN SAID FEEDING WHEELS AND SAID NEEDLE BED, SAID GUIDE MEANS INCLUDING A PIVOTED ARM SUPPORTING ONE OF SAID GUIDE MEANS AND MOUNTED FOR PIVOTAL MOVEMENT IN RESPONSE TO CHANGES IN YARN TENSION AT SAID NEEDLE BED; AN ELECTRICAL CONTROL CIRCUIT FOR SAID MOTOR ACTUATABLE BY SAID PIVOTED ARM, SAID CONTROL CIRCUIT INCLUDING A NORMALLY OPEN MAGNETICALLY ENERGIZED SWITCH OPERABLE BY SAID PIVOTED ARM; AND A RESISTOR ADAPTED TO BE SHORTED BY SAID SWITCH TO MOMENTARILY INCREASE THE SPEED OF SAID MOTOR WHEN SAID PIVOTED ARM IS DEFLECTED TO ENERGIZE SAID MAGNETIC SWITCH.

Images