US2506645A - Warp knitting machine and method of operation - Google Patents

Description

y '1950 w. D. KELLOGG ET AL. 2,506,645

WARP KNITTING MACHINE AND METHOD OF OPERATION Filed Jan. 11, 1945 2 Sheets-Sheet l y 1950 w. D. KELLOGG ET AL 2,506,645

WARP KNITTING MACHINE AND METHOD OF OPERATION Filed Jan. 11, 1945 2 Sheets-Sheet 2 INVENTORS mm 2 rim 6mg 4. 4y

as; quickly:::as :possible.

7 fective needles.

Patented May 9, 1950 ..WARPLKNITTING:MACH]NE AND METHOD "OF OPERATION William DirKellogg;Amsterdam; N. :Y.,:.and Rich- :ardrEi-Eshleman, West Chester,=and WalterT. i Morris,*Norwood, "2a., assignors, by mesne as- .signments, to American -Viscose Corporation, LPhilddlhhia, 1a,, ascorporation v.oi" Delaware App'IicationJanuary II, 1945,?Serial No. 572366 .59 Glaims.

This ;-invention relates :towwarp nor *tricot' knitlting :machinesrsandtit'i'isvparticuiany iconcern'ed -.with ;a methodz'a-ndz arrangement-Tier elinmating stop andistart marks or sorreducingsuch marlrs that theyicompletelydisappearzduringthe:normal saiteretreatment iof theiiabrics,esuch aszdeesizing, bleaching, tdyeingiand: the; like.

In: accordancezwith'thepresent:invention; when the imac'hine. isrtstopped'ior any purpose "whatsoever, ltI1iSZtOPP dQJSIquiGkly'iasg' possibleand in are startingzthermachine,iitis brought'tofull speed The 'quickzstoppingcand .s'ta'rting imay i be accomplished :by', variousnmeans such a'sithe-rprovision::ofFaeconstanti.speedrmotor, which has :a Zihig'h'FStfiItiHg torque and rapidly :comes upztospeedealong'ewithrarr arrangement for fpluggingFathetmotor: (ice, reversing thezeurrent throughithe"windingsofthezmotor) to :lefiect-stoppage thereof. Alternativ-ly, rasipowerfulibraking system may befiairangedwinsteade'of:plugging the :motor. Again, zbothca brakingsystemeanda motor plugging systemimay-be'zassociated together. The initiationiof "operation of the". stopping: means -:is caused to ;takez'placez inrtimed "relationship to the "knitting cycle; or whatais the equivalent; inttimed --relationship to 'the'rotation" of the cam shaft; so thatstopping'isinitiatedimapredeterminedportion of the knitting cycle and is completed: in less than a complete knitting cycle. Preferably, .this initiation is soxcontrolledwas :to occur:- 'duringtthe motion of thexneedlesifrom their: pressing position where r--their "bearclsaare closed their low position, .that is, during: the Idrawing of the. new loops ithrough: the-previously formedloops and the entire operation' :of =-stopping is preierably accomplished-by the timethatthe needles have returned to: the vieinity of 1 their slowest- :position v and in no eventrlater than r their *arrivahin their next lappingpositionin preparation fon the formation of the next i-loopsathereabout. Besides. reducing .the stop: and start marks, .stoppin'geat this.- phase of .the knittingeyele assures thatthe guidesalways cometo rest intheir forward position where theyeare:accessiblelfor threading, threadingrindividual threads and. for replacing. brokenonde- Heretofore, after stopping tto correct canyiof these .trouhles tit .ihas generally been necessary. for; the ioperator. to.. drlve the ma- .chine by. hand .imtil .Lthe guides were brought "forward and this hand operation. caused. serious marks akin to the stop and start marks.

In accordance with the present inventionethe initiatiomoi?the-1stopping.ofethainaclziinelis thus controlledpregardless :bf the-zeausa; of stopping, *whetherilfor.the-purpose;ofizmaklng fldiustments winthe;iznoeration:of-V-the;machine,sorf'fonservicing v 2 v V theknitting elements (known as the insides to the tricot trade and consisting of :needles, sinkers and guides) for threading the machine, replacing broken needles, tying in brokenthreads, etc., and is also thus controlled regardless of whether the stopping is initiated manually =0! automatically by detectors for breakage; or: slack tensionin the yarns.

The invention is illustratedinpa specificaem- .bodiment in the accompanying drawings, .in which:

:Figure .1 shows-the electrical connections .(in conventional 1 symbols) -for5functional1y correlating the parts in a preferred embodiment'of' the invention,

Figure'2 illustrates the relationship of certain parts shown in Figural to "the camshaft :and knitting elements of a warp knitting machine;

vFigure .'-3,-is a crossesection of; the-timingxwheel taken. on-line. III-III of Figure 2; and

Figures 4 to '7 illustrate the:knitting cycle.

.In'awarp knittingmachine, the knitting cycle :Vcomprises generally the following sequence of steps" takensby the knitting elements: referring to the relationships-shown; in Figure has the ;starting position. :InFigure :4, the guides :1 Grand-LG: are in their forward position inrfrontnof-tthe .needlesw-N which-are in their lapping position of intermediate height with their'shanks extending through the most recently formed loops ;of

the fabricF. As shown :in-Figure'the guides .move baekof theneedles and then move laterally vto'lap their threads around-theneedles. Then the guides return to their forward positionsato complete the.-1oops-around theneedles, at which time the need-les'rise to their uppermost tposi .tionatoplace the mew-loops under their beards. .As the needles start .downwardly,-. therpresser.- bar .P. moves forward to close the beards of. the: needles over these'loops and the sinlrersS I'IIOVB1b3Ck somewhat. so that the relative positionsof' Figure 6 are reached. Then the needles ..continue to move downwardly todraw the new loops-within the closed beards through. the previously: formed loops surrounding the shanks of the; needles, thereby. reaching the position shown in Figure 'l.

.From "this position, the needles rise to-lapping positienras: shown in. Figure 4.

YWith reference to the illustrative embodiment of the ;invention shown. in Figures 1 -andz-2,- .a

three-phase constant speed 0A. C. -.motor 4! alias one lead 3 grounded :and the other; two, .4 -and.- ,conneetediir parallel to one side: of i-theswitches island '1'. Fox's-normal operation .of the .r-motor, powerqisrtransmitted to. themotor 2- fromithe line 8':-;through 1 the -switch 6. .It will :be motedthat the line 8 is connected to the line side of switch I, so that the current will take the reverse direction through the motor, as compared to that taken when the line 8 is connected to the motor through switch 6, thereby providing for plugging of the motor to stop it. One phase of the three-phase power line is grounded as shown at 9 to complete the three-phase circuit to the motor in both normal and plugging operations.

A control circuit, provided with current fro an auxiliary line It supplying A. C. current in a one-phase system (or, if desired, connected instead to the line 8 so that it derives its current therefrom) comprises a solenoid H, a switch I2 for manually stopping and starting, and a switch I3 iorautomatically stopping the machine, said three members I2 and I3 being in series. Shunted across the switches I2 and i3 is a timing circuit comprising the leads I4 and I5 through the timing device l5 and the switch IS in series. For controlling the duration of the action of the plugging circuit, there is provided a switch ll, which is responsive to rotative speed and is held in closed condition when the machine is in operation by virtue of the pulley l8 connected by belt I9 and pulley 2D to the cam shaft 2| (see Figure 2) and is, on the other hand, opened upon stopping of the cam shaft. The switch I? is in series with a solenoid 22 and a switch 23, and derives current from the auxiliary line For the plugging switch any form of centrifugal switch may be used. An example of an equivalent form of switch which may be used as the switch I1 is a type made by the General Electric Company, Schenectady, N. Y., known as the G. E.

plugging switch CR-2962, and described in the circular GEA-35'71 published by that company.

A core 24 is associated with solenoid so that energization of solenoid causes closing of switches 6 and I6 and opening of switch 23, whereas a spring 25 opens switches 6 and IB and closes 23 upon de-energization of solenoid II. A core 26 is associated with solenoid 22 and is so connected to switch I that energization of the solenoid 22 closes switch I, a spring 21 opening switch I upon de-energization of the coil.

' The timing device I5 merely comprises a conductive band 28 carried upon a wheel structure secured for rotation with cam shaft 2| by cap screws 29 (see Figure 3). The band 28 does not completely encircle the wheel, but is interrupted by an insulating segment 30. Two contact elements 3| bear upon the exposed surface of the band on the wheel, so that current through this branch of the circuit is interrupted periodically by the segment 39. The wheel structure, as shown in Figure 3, is preferably adjustable angularly with respect to the cam shaft 2|. For this purpose, it may comprise a central hub portion the segment 3|! can thus be adjusted at will with respect to the cams 31 on the cam shaft 2| (see Figure 2) so that stoppage is initiated at some point during the movement of the needles from 1 their pressing. position shown in Figure 6 to their next low position as shown in Figure '7.

V The automatic stopping switch I3 may be controlled by any conventional electric, mechanical or photo-electric device for detecting breakage inyarns or development of excessive slack-therein.

This detecting device is shown as a capital D in a block and referred to by reference character 4| in Figure 1, and may take the form of any conventional, detector and relay, .such as shown in Quick 2,010,928,Stan1ey 2,290,257, Hayes 2,330,212 and Hayes 2,345,599. As shown, the detector may operate the switch l3 by means of the relaycomprising a core 42 carried by switch 53, which is normally held in closed position by the spring 43 and solenoid 44 connected in series with the detecting device 4| and the line I0.

' The operation of the circuit may be described as follows: Whenthe machine is in operation, switches I2, l3, 6 and I5 are closed, current flowing from the auxiliary line In through the solenoid I I to holdswitches 6 and I5 closed and switch 23 open, so that the normal driving current passes through the switch 5 to the three-phase motor 2 and the cam shaft 2| rotates, causing the switch IT to be closed by "virtue of "the centrifugal force. Upon opening either'switch I2 manually or switch I3 automatically, it will be seen that the current through solenoid I I will be cut ofi when the contacts 3| strike insulating segment 3|] of the timing device [5. Because of the timing device, the opening of switch l2 or |3 cannot initiate stopping of the motor, but really presets the stopping system in condition for actuation when the predetermined portion of the knitting cycle mentioned above has been reached as controlled by the insulating segment 30." De-energization of 0011 opens switches 6 and I6 and closes switch 23. Closure of switch 23'energizes coil 22, thus closing the switch 1 and plugging the motor 2. However, when the motor has been stopped, switch I! opens by virtue of loss of centrifugal force, so that coil 22 is de-energized and switch I is opened to prevent rotation of the motor in the opposite direction beyond stopping position.

While the invention has been illustrated with the use of an A. C. motor, a direct current motor may be used instead and a modified system, such as that provided in a Thymatrol, can be used for plugging it. As statedabove, a braking system may also be initiated'to assist the plugging action of the motor, or a braking system may be supplied instead of the system for plugging the motor. I

By controlling the quick stopping of the warp knitting machine so that it occurs only during that portion of the cycle beginning with the pressing position shown in Figure 6 and ending with the next lapping position shown in Figure 4, and then quickly starting the machine, it has been found that stop and start marks can be substantially entirely eliminated. By so controlling the quick stopping that the knitting elements of the machine come to rest with the needles in the vicinity of their low position, the marks are eliminated and the machine presents the most favorable condition for the servicing of the elements. In either case, the machine can be serviced :without turning it over by hand, thereby avoiding additional marksoccasioned by this operation It is to be-understood-that the description herein is illustrative only, and that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. In combination with a warp knitting machine having knitting needles, a cam shaft for controlling the cycle of operation, an electric -motorfor driving thecam shaft, means for stopping th machine comprising an auxiliary control circuit having an electromagnetic means for hold ing closed the circuit to the motor, said control circuit having two branches in parallel, one of the branches comprising a device operated in timed relation to the knitting cycle for intermittently interrupting the current therethrouglti and the other branch comprising a switch adapted to be opened to preset the stopping means in condition for initiation when the next interruption in the current is efiected by the device in the first branch.

2. In combination with a warp knitting machine having knitting needles, a cam shaft for controlling the cycle of operation, an electric motor for driving the cam shaft, and means for, stopping the machine comprising an auxiliary control circuit having an electromagnetic means for holding closed the circuit to the motor, said control circuit having two branches in parallel, one of the branches comprising a device operated in timed relation to the knitting cycle for intermittently interrupting the current therethrough and the other branch comprising a switch adapted to be opened to preset the stopping means in condition for initiation when the next interruption in the current is effected by the device in the first branch, additional electromagnetic means for connecting the motor to a reversed current circuit, a control circuit comprising a switch arranged to be closed by the first-mentioned electromagnetic means upon deenergization thereof and a switch in series therewith adapted to be opened and closed in response to decrease and increase in rotative speed respectively, said switch being arranged to be diven by the cam shaft.

3. In combination with a warp knitting machine having knitting needles and a cam shaft for controlling the cycle of operation, electrical means for stopping the machine, means comprising a timing switch element carried by and rotated by the cam shaft for controlling the initiation of the stopping means so that initiation thereof occurs at a predetermined position of the knitting cycle, and a movable switch member connected in parallel with the timing switch element for presetting the stopping means in condition for actuation.

4. In combination with a warp knitting machine having knitting needles, a cam shaft for controlling the cycle of operation, an electric motor for driving the cam shaft, a motor circuit, a control circuit having electromagnetic means for holding closed the motor circuit, means for stopping the machine comprising switch means in the control circuit, and means for controlling the actuation of the switch means to interrupt the control circuit so that initiation of the stopping means occurs during a predetermined portion of the knitting cycle.

5. In combination with a warp knitting machine having knitting needles, a cam shaft for controlling the cycle of operation, an electric motor for driving the cam shaft, a motor circuit, a control circuit having electromagnetic means for holding closed the motor circuit, means for stopping the machine comprising switch means in the control circuit, means for controlling the actuation of the switch means to interrupt the con-. 1:

trol circuit so that initiation of the stopping means occurs during a predetermined portion of the knitting cycle, means for plugging the motor, and centrifugal means driven by the motor for initiating operation of the plugging means when the speed of the motor falls below a predetermined limit.

6. The method of controlling the operation of a power-driven Warp knitting machine comprising quickly stopping the machine from normal operating speed within less than the period of a complete knitting cycle so that the entire operation of stopping is completed during that period of the knitting cycle in which the needles move from their pressing position to their next looping position, servicing the machine and subsequently quickly starting the machine without manually changing the positional relationship of the elements from that existing when the machine first comes to rest at the conclusion of said stopping.

7. The method of substantially eliminating stop marks in warp knit fabrics comprising the step of completely stopping a power-driven warp knitting machine from normal operating speed during that period of the knitting cycle between the time of pressing the beards of the needles closed to the approximate time when the needles next reach their lowest position, servicing the machine and subsequently quickly starting the machine without manually changing the positional relationship of the elements from that existing when the machine first comes to rest at the conclusion of said stopping.

8. The method of servicing the knitting elements of a power-driven warp knitting machine during operation thereof without detrimentally affecting the fabric loop formation comprising stopping the machine from normal operating speed within less than the period of a complete knitting cycle so that it comes to rest at a predetermined portion of the knitting cycle in which the guides are in a forward position in front of the needles, and servicing and subsequently starting the knitting elements without changing the positional relationship of the elements from that existing when the machine first comes to rest at the conclusion of said stopping.

9. The method of servicing the knitting elements of a power-driven warp knitting machine during operation thereof without detrimentaliy afiecting the fabric loop formation comprising stopping the machine from normal operating speed within less than the period of a complete knitting cycle so that it comes to rest at a predetermined portion of the knitting cycle in which the guides are in a forward position in front of the needles and the needles are in the vicinity of their lowest position, and servicing and subsequently starting the knitting elements without changing the positional relationship of the elements from that existing when the machine first comes to rest at the conclusion of said stopping.

WILLIAM D. KELLOGG. RICHARD F. ESHLEMAN. WALTER T. MORRIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,901,418 Smith Mar. 14, 1933 1,971,427 Quick et a1 Aug. 28, 1934 2,010,928 Quick Aug. 13, 1935 2,015,106 Gastrich Sept. 24, 1935 2,040,047 l-iaines et al May 5, 1936 2,050,389 Simpson Aug. 11, 1936 2,363,535 Lambach Nov. 28, 1944

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