US2383838A

US2383838A - Tension control, stop mechanism, and warning signal for knitting machines

Info

Publication number: US2383838A
Application number: US543248A
Authority: US
Inventors: Robert N Auble
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-07-03
Filing date: 1944-07-03
Publication date: 1945-08-28
Anticipated expiration: 1962-08-28

Description

Aug. 28, 1945.

i TENTION CONTROL, sToP MECHANISM, AND

WARNINGSIGNAL FOR KNITTING MACHINES R. N. AUBLE Y 2,383,838

Filed July s, '1944 5 @v -Hq. j.

Patented-Aug.` 28, 1945 TENSION CONTROL, STOP MECHANISM, AND WARNING SIGNAL FOR KNITTING MA @EINES Robert N. Auble, indianapolis, llml.

Application July 3, i944, Serial No. 543,248

i7 claims. (ci. .ss-'163) This invention relates to improvements in tension control and stop mechanisms for knit ting machines, coning machines and the like.

It is particularly adapted toequalize tension on yarn, thread, etc., in machines in which the yarn is freely'fed to the machine without restraint or restriction at the vsource of supply, but which encounters inthe machines variable factors of demand, such as, for example, are found inthe carrier arms of hosiery knitting machines, which in travelling forward and backward across the needle. bars subject the yarn to a constantly varying rate of travel and consequent va-rying tension.

This invention is also particularly adapted to stop the knitting machine should the yarn or thread be broken at any point, should it develop a knot r slub such as wouldbreak the thread in its travel through the machine, or should any factor develop a tension on the thread either greater or less than the predetermined limits imposed by the initial adjustment of the device. i

It is likewise particularly adapted to energize a warning signal such as to light a warning lamp or ring a warning belhand at the instant the machine is stopped by reason of a thread break, run out, or increasedtension, etc. Such signal may be individualized to enable the operator of the machine to locate promptly the source of trouble by individually indicating the thread which has caused the stoppage.

Other advantages and novel features of the invention will be lset forth more fullyv in the speciilcation. y i

The full nature of the invention will be under- .switch contactorsr 9 and the tension `arm 4. Same are offset axially relative to pin 20.

In its preferred' form a single switch member I2 is employed to energize and thus actuate an electronicrelay or the like, which in turn may light a Warning lamp and open an electric cirthe forward (arm associated) end of pin 20,

stood from the accompanying drawing and the y following description and claims:

In the drawing:

Fig. 1 is a. central section vof the essential parts of the device.

Fig. 2 is a perspective view of the device.

Fig. 3 is a wiring diagram of a circut and in which is included a plurality of the, devices and one `preferred arrangement of warning signals.

Fig. 4 is a perspective view looking toward the rear of the spindle member, contactors, counter weight and tension arm.

The frame consists of base member I6, upper eyelet supporting tongue I5, side brackets I8, and the window Il in the base. Brackets I8 carry and support on point bearings 6 the spindle member or spindle 8, which is pivoted on point bearing sockets 5 and moves freely in a vertical plane. through an angle of approximately 1059.

cuit to theA driving motor and its associated dy- .namic braking mechanism of a machine such` as a knitting or coning machine. Al second switch blade I2a may be mounted, however on the basel member I6 and selectively contact a second pair of contactors 9a and Illa on spindle t, similar to contactors 9 and Ill, should .it be desired to separate the warning light function from the stop motion function of the electronic relay. The contactors 9 and II) and 9a' and Ia are each oppositely oii'set from pin 20.

The switch blade I2 is insulatably supported by insulation plate I3 on the base member I6. Switch blade I2a is similarly mounted on the base. Also vmounted on said base member I6 is a flat spring IB wi-th an angular end which y extends through the window I'I and normally lies above the counterweight ,1. The end 2I of said spring I 4 is so positioned that it is engaged by when the tension arm d approaches the upper I progressive.

In normal use thread 22 is threaded through porcelain eyelet Icarried by tongue l5, vthence through eyelet 2 on tension arm t, thence through eyelet 3 in base I6 and thence to the machine upon which the present. device is mounted. Thread movement through the eyelets is in the direction shown by the arrows. Said movement is resisted by the friction of eyelets I and 2 'upon the thread. The amount of frictional resistance for a given type lof yarn is proportional to the velocity of thread movement and to the position of the tension arm Il. Since tension arm B is free to move in a vertical plane, which is also the plane of the strands of yarn, eyelet 2 is lifted toward eyelet 3 as the velocity ofthe movement of the thread is increased, and conversely is lowered again toward its lower position as velocity of movement is decreased. Thus, except in the case of breaks, runouts, or slubs, the position of the tension arm 4 is at all times responsive to variationsin the rate oi' travel of the yarn or thread to the knitting or like machine.

1t 1s to be noted, however, that should a knot or slub develop in the source of supplyror should the thread be broken at' any point, then the position of the tension arm 4 is no longer responsive solely to the friction in eyelets I and 2, but is also responsive to the undesired change in tension. Should such a change in tension develop at the source of supply, then tension arm 4 drops to its lower limit position in the casel of too little tension, or is lifted to the upper limit position if the tension be too great. As the tension arm 4 approaches its upper limit position, its pin 2li engages spring I4 at 2| in such a way that iree movement of the said tension is impededL slightly, so that switch contact 9 will not immediately contact switch blade I2, except as the tension is such as probably will break the thread if such tension be continued. The foregoing also applies to contact 9a and switch I2a when same arev used. Spring I4 is selected and adjusted to accommodate the thread which is being currently used.

The tension arm 4 and counterbalancing weight 1 are so constructed .that the moving member is in exact equilibrium when the tension arm 4 is positioned in the same straight line as pin `2t which carries the counterbalancing weight 1 at its opposite end. Adjustable control of tension is secured by bending the tension arm 4 downward, thus moving the center of gravity of the moving system to a position below the points of support, in this case bgelow a horizontal line drawn through point bearings 6. When the thread or yarn is moving through eyelets I, 2 and 3, as hereinbefore described and in the direction of the arrows,` eyelet 2 is lifted toward eyelet 3. Thus the tension arm 4 is a lever system operating about a center of moments at the point bearings B and arranged in such manner that the center4 of gravity oi the whole moving system is lifted by the tension arm 4 in its upward movement.

'I'he mechanical advantage of the said lever 'system is the ratio of the length of the tension arm to the distance to which the center of gravity was lowered by the bending of the tension arm downward as described. Said mechanical advanaasaese proximately parallel and of their lifting force is their sum. But as tension arm 4 is moved upward ,the angle between the -two lifting forces is increased, and their treatment is reduced.'

It will be also observed that the effective lifting component of the force is at right angles to tension arm 4', and that this said eiective lifting component of the force is proportional to the sine of the angle through which the tension arm has been moved, increasing as the tension arm approaches its upper position.

Thus the resisting force due to the lifting of y the center of gravity increases and the eiectfile component of the lifting force increases in the same proportionate rate so that they are at all l times in balance againsteach other, so that the for exemplication.

resultant edect is to produce a constant tension `onI the yarn, within'the limits predetermined by and the former to terminal 4I by normally closed switch 41 and line 48. Terminal 42 has line 49 i I connected thereto and switch contact '50.

When switch 41 is closed. the motor is energized. When it is opened, said switch engages contact El! and energizes the dynamic brake in tage is therefore adjustable by the'amount of bending of the tension arm, and when onceltrhas been adjusted tol provide thedesired tension, no further adjustment is necesssary. Bending is not the only method of adjustment, but appears to be the easiest.

'In the adjustment which has been described it will be observed that as the tension arm 4 is lifted towardv eyelet 3, the center of gravity must be lifted, and since the moment of force exerted by said center of gravity is proportional to the sine of the angle' of the movement, resistance to move-V ment is least at the lower position and greatest at the upper position of said arm.

It is to be observed likewise that in the manner of threading the yarn through eyelets I, 2 and 3, two supporting strands of thread, that is one between eyelets I and 2 and the other between

eyelets

2 and 3, operate to lift tension arm 4. At the lower position, the said two strands are aP- the well known' manner, the braking circuit comprising line 43, line 45, switch d1, line 69, line 46 and line 44. 48, line 45, switch 41, line 48, line 46 and line.43.

Power lines

43 and 44 are connected to the primary 5I of a power

transformer having secondaries

52, 53 and 54. Relay 55 is in series with secondary 54 and plate 5B of tube 51. This ,tube includes grid 58,cathode 69 and filament or heater B0.

Secondary 52 has line BI connectedl to the cathode 59 and filament B0. The latter is connected across secondary 52 by series connected

lines

62 and 63. Line 6I is extended at 64 and connected at 65 to a plurality of parallel connected spindles 8. Juxtapositioned thereto are the spring contacts I2a and I2, each of the former connecting by a line -66 to signal lamp 61 connected by line 68 to line 63j Thus each tension arm herein has a signal light and same is indimachine.

vidual to that arm so the operator can readily locate the thread break; interference, etn, in the All contacts I2 are connected by line 59 to tap 1b of resistor 1f-12,/ the latter being connected by line. to secondary 53.- Tap 14 from sec; ondaries 53-54 connects at 15 to line 6|. Line 16 from resistor 1I connects to grid 5B.

Now when any arm (spindle 8) engages spring I2 adjacent thereto (spindle 8 having. upper and lower limit contacts 9 and Ill) the tube is energized and relay liliy is energized to open switch 41 to the motor and close switch 41 to the brake, Thus immediately upon any arm 4 attaining its upper or lower limit the motor is deenergized and the brake applied and the individual warning signal- (as indicator-or locator) is energized.

the effective rsultant effective- 'Ihe motor circuit comprises line An audible signal may be in multiple with each of thread failure and cxpedites machine reoperation.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readilyrsuggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:` 1. A constant tension device suitable for knitting, coming and `like machines, having in combination a rocking lever with two arms, one of' 3 5. The structure as defined by claim 1 wherein a switch is mounted with lrespect to said lever and `is operated by movement thereof, a suitable source of electrical supply connected to the switch, an electric motor, and braking means for machine operation and stoppage respectively and connected to said supply, means controlling the latter connection, and means controlled by said switch for actuating said last mentioned means for effecting motor stoppage, said first mentioned controlling means including a switch normally biased to motor circuit position and movable by the lastmentioned means to motor open'circuit and brake closed circuit position. y

6. The structure as defined by claim 1 wherein a switch is mounted with respect to said lever and is operated by movement thereof, a suitable source of electrical supply connected to the switch, an electric motor, and braking means for machine operation and stoppage respectivelyl and connected to said supply, means controlling the latter connection, and means controlled by said switch for actuating said last mentioned means for effecting motor. stoppage, said iirst mentioned controlling means including a switch normally biased to motor circuit position and movable by said arms being longer and having at its end an eyelet for guiding yarn and the other end of said arm being shorter and carrying a counterbalancing Weight adjustably-positioned thereon, the said entire lever system being pivoted to move freely in a vertical plane about a' point of equilibrium, means pivotally supporting said lever, the said long arm being adjustable to provide a change in the position of the center of gravity of the said lever system in a vertical plane including the sweep of said arm, the said center 'of gravity being lifted by upward movement of said lever and oiering constantly increasing resistance to said movement as the angle through which it has moved is increased, a second eyelet positioned substantially in the plane of movement of said lever to guide yarn from a source of supply to the said first eyelet on said long lever arm, and a third eyelet also positioned substantially in the plane of movement'of the lever machine, the said three eyelets being positioned with respect to each other so as to provide friction on the yarn and thereby to provide a constantly increasing effective lifting force on the long arm of said lever.

2. A tension device as dened by claim 1 wherein there is provided resilient means engageable by the lever as the same'approaches its upper limit of movement and for` progressively impeding further movement toward said upper limit.

source of electrical supply connected to the switch, an electric motor, and braking means for machine operation and stoppage respectively and connected to said supply, means controlling the latter connection, and means controlled by said .switch for actuating said last mentioned means for effecting motor stoppage and braking of the machine.

` to guide yarn from the said first, eyelet to the v the last mentioned means to motor open circuit and brake closed circuit position, said last men,

tioned means including a relay.

'7. The structure as dened by claim l wherein a' switch is mounted with respect to said lever and is operated by movement thereof, a suitable source 8. A constant tension devicecomprising three substantially coplanar thread guides, twoof the guides being comparatively close to each other and the intermediate guide being simultaneously.

movable toward or away from the same, a pivotally supported, counterbalanced substantially horizontally directed arm for said intermediate movable guide and beneath the other two guides, said arm moving substantially in the plane of `said guides, the directionand extent of the arm movement being proportional to the thread tension,

and resilient means operatively engageable by the arm in its guide movement toward the other guides and progressively impeding such arm movement toward ysaid other guides.

'9. A tensin device as defined by claim 8 wherein there is provided acontrol switch, and

means vcarried by the arm for operative engager.y

ment with the switch when the arm is tilted closesttothe said other guides. v

. '10. A tension device as dened by claim 8 wherein there is provided a control switch, and

means carried by the arm for operative engagement with the switch when the arm is released from thread tension.

dual, arcuately spaced means carried bythe arm for selective operative engagement with the switch when the arm is tilted closest to said other guides or when the arm is released from thread tension.

12. In a control system for knitting, coning and like machines having a driving motor and a brake, and switch means differentially controlling same, the combination of a single means controlling said switch means, a plurality of yamtensioning devices, there being one for each yarn and having a portion movable proportional to the tension or lack of same, responsive switch means brake, and switch means diierentially controlling same, the combination of a single means controlling said sim'tch means, a plurality of yarn tensioning devices, there being one for each yarn and having a portion movable proportional to the tension or lack of same, responsive switch means for each device and actuable by said portion at the limits of portion movement, a warning signal for each device and operable thereby and energizable by the second mentioned switch means at either limitI of portion movement,and a singleA means in series with all of said second mentioned switch means and operable by any one of same for actuatingsaid rst mentioned switch means, and arl-audible signal in multiple with the said single means and simultaneously operable therewith.

14. In a control system for knitting, coning and like machines having a driving motor, and a brake, and switch means differentially controlling same, the combination of a single `means controlling said: switch means, a. plurality of yarn tensioning devices, there being one for each yarn and having a portion movable proportional to the tension or lack of same, responsive switch'- f01' @lich device and actuable by Said mltifm at' means for each device and actuable by said portion at the limits of portion movement, a warning signal for each device and operable thereby and energizable by the second mentioned switch means at either limit of -portion movement, and a single means in series l withy all of said 'second mentioned switch means and operable by any one of same for actuating said irst mentioned switch means, said single means comprising an electronic relay and an electronic tube.

15. In a controlsystem for'knitting, coning and v said single means comprising an electronic relay and an electronic tube, and an audible-signal in like machines having a driving. motor and a brake, and switch means differentially controlling switch means and operableby any one of same for actuating said rst mentioned switch means,

multiple with the said single means and simultaneously operable therewith. .i

16. In a control system for knitting, coning and like machines having a driving motor and a brake, and switch means diierentially controlling same, the combination of a single means controlling said switch means, a plurality of .yarn tensioning devices, there being one Afor each yarn and having a portion movable proportional to the tension or lack of same, responsive switch means for each device and actuable by said portion at .the limits of portion movement, a Warning signal for each device and operable thereby and. energizable by the second mentioned switch means at either limit of portion movement, and a single means in series with all of 'said second mentioned switch means and operable by any one of same for actuating said first mentioned switch means and a visual signal in multiple with said single IDBanS.

17. In a control system forknitting, coning and like machine having a driving motor and a 40 brake, andswitch means differentially controlling- @s tension or-lack of same, responsive switch means said single means comprising an electronic relay and an electronic tube.

y ROBERT N. AUBLE.