US3225570A - Automatic stitch control - Google Patents

Description

Dec. 28, 1965 MISHCON AUTOMATIC STITCH CONTROL 5 Sheets-Sheet 1 Filed June 27, 1963 INVENTOR. LESTER MISHCOM @145,

ATTORNEY WITNESS Dec. 28, 1965 L. MISHCON AUTOMATIC STITCH CONTROL 5 Sheets-Sheet 2 Filed June 27, 1965 IN VENTOR. L ss'rsn MISHCON ATTORNEY WITNESS Dec. 28, 1965 MISHCON 3,225,570

AUTOMATIC STITCH CONTROL Filed June 27, 1963 5 Sheets-Sheet 3 92 INVENTOR,F 3 5 LESTER MISHCON BY WITNESS X /f WVK ATTORNEY Dec. 28, 1965 1.. MISHCON 3,225,570

AUTOMATIC STITCH CONTROL Filed June 27, 1963 5 Sheets-Sheet 4 I NVENTOR. LESTER MISHCON WITNESS BY X /U/ Z w v ATTORNEY Dec. 28, 1965 MISHCON AUTOMATIC STITCH CONTROL 5 Sheets-Sheet 5 Filed June 27, 1965 I I IL I'N VEN TOR. LESTER M/sncolv WI TNE S5 United States Patent C) 3,225,570 AUTOMATI STITCH CONTROL Lester Mishcon, Miami Beach, Fla assignor to The Singer Company, a corporation of New Jersey Filed June 27, 1963, Ser. No. 291,011 16 Claims. (Cl. 66-132) This invention relates to the manufacture of fabric and more particularly to a control system for regulating the operation of fabric making machinery for the continuous production of fabric of uniform characteristics.

In the preferred embodiment of this invention; as illustrated in the accompanying drawings, this invention is applied to a circular knitting machine and serves to regulate the yield of the resulting knit fabric. In the manufacture of knit fabric, production of a fabric of uniform density or yield in terms of weight of the fabric per unit area is difiicult because many variable factors are involved. For example, in a circular knitting machine, some of those factors include yarn tension, the condition of the yarn, the stroke of the knitting needles, frictional resistance to movement of needles, and tension applied to the fabric as it is being manufactured.

In my United States application Serial No. 278,135, filed May 6, 1963, and entitled Yarn Controlling Device for Knitting Machines, a single yarn furnishing unit is provided which permits an operator, at his discretion, to deliver the yarns to the knitting instrumentalities in a selected one of a wide range of conditions either in measured quantities precisely meeting the demand of the knitting instrumentalities or under accurate and consistent tension. The yarn controlling device of the above referenced patent application provides for an adjustment under the influence of a knitting machine operator whereby the resulting yield of a knit fabric may be changed.

In my United States application Serial No. 160,439, filed December 19, 1961, entitled Fabric Yield Computing Device, now United States Patent Serial No. 3,099,- 142, apparatus is described for measuring and continuously indicating the yield of a fabric being produced during the operation of a fabric manufacturing machine.

While devices such as those described in the above referenced patent applications can be helpful to a machine operator, assisting him in maintaining the knitting machine in that state of adjustment which might produce fabric of substantially uniform yield, they require continuous supervision and some degree of manual adjustment by an operator. Supervision by an operator imposes a burden on the manufacturer because of the need for highly reliable personnel having well-developed skill in making manual adjustments in appropriate increments at the proper time in order to avoid spoilage of fabric. Hence, it has long been a most significant need of the fabric manufacturing industry to have a machine capable of operation without continuous supervision to produce a highly uniform yield. In meeting this need, the devices of this invention provide a measurement of the actual yield from the machine, compare that yield measurement with a desired yield, detect any difference therebetween, and efifect a machine adjustment in response to any such difference to maintain the desired yield. In accordance with this invention, a knitting machine is provided for concatenating fibers to form a web having an identifiable characteristic. During operation, the knitting machine can be regulated to vary the characteristic of the web. The characteristic of the fabric web is measured during operation of the machine and a measurement response is provided as a function of the characteristic of the fabric web. The measurement response is compared with a predetermined reference standard and the machine is regulated in response to the difference be.- tween the measurement response and the predetermined reference standard to reduce that difference.

This invention is described below with reference to particular preferred embodiments thereof shown in the attached drawings in which:

FIG. 1 represents a side elevational view of multi-feed circular knitting machine having my invention applied thereto;

FIG. 2 is an enlarged cross-sectional view of a portionof the knitting machine of FIG. 1 taken substantially alongline 22 with certain elements thereof rearranged for convenience of illustration;

FIG. 3 represents a top plan view of a computing de-. vice with portions of the casing thereof removed and:

broken away;

FIG. 4 is a cross-sectional view taken substantially: along line 44 of FIG. 3, representing a side elevation; of the mechanism of the computing device within the cas- FIG. 5 is a cross-sectional view taken substantially along line 5-5 of FIG. 3 representing a rear elevation.

of the mechanism of the computing device;

FIG. 6 is an enlarged cross-sectional view along line; 66 of FIG. 1 representing a top plan view of the yarn control device of the knitting machine;

FIG. 7 is a schematic drawing of an electro-mechan-- ical control system for regulating the fabric yield of a knitting machine in accordance With this invention;

FIG. 8 is a schematic drawing of a mechanical system for regulating the fabric yield of a knitting machine in,

(FIG. 2) having a depend-ing flange 14 formed withgear teeth 15 and anupstanding flange 16 to which aneedlecylinder 17 is secured. Thegear teeth 15 mesh with a' pinion 18 fast on ashaft 19 which is driven by anelectric motor 20 by way of aclutch device 21. Thegear ring 13 is constrained rotatably in the housing ring ll'by aretaining ring 22 secured to the housing ring.

The outer wall of theneedle cylinder 17 is formed' with evenly spacedvertical slots 23 each slot slidably ac' commodating alatch needle 24 formed with abutt 25. As the needle cylinder is rotated, the needle butts are successively influenced alternately byneedle raising cams 26 carried by theretaining ring 20 and then bystitch cams 27 carried by asection block 28 on thecam retaining ring 22. Each set ofcams 26, 27, of which there may be many disposed outwardly of the needle cylinder, cooperate to influence endwise motion of the needles in seriatim to form a row of stitches in a fabric F by incorporation therein of loops formed from one of a plurality of yarns Y which are fed to the needles as the needles are being influenced by theearns 26 and 27.

Fast on thegear ring 13 so as to rotate with theneedle cylinder 17 are a pair of take-up driving brackets 29 which engage with and drive a fabric take-up indicated generally at 30 in FIG. 1. Secured on one of the take-up driving brackets 29 is asupport frame 32 carrying astud shaft 33 on which is journaled a fabric drivenwheel 34 provided peripherally with fabric engaging pins. Secured caxially with thewheel 34 is asprocket wheel 35 engaging anendless chain 36 which also passes about an idler sprocket 37 journaled in the support frame. In the pre ferred embodiment illustrated in the drawings, one of thelinks 38 of thechain 36 is formed higher than the remainder of the links so as to provide a cam surface engageable with a contact arm orroller 39 of anelectrical switch 40 secured on the take-up driving bracket 29 adjacent to thesupport frame 32. Theswitch 40 is of the normally-open variety and is closed momentarily by thecam link 38 upon the passage of a predetermined quantity of fabric relatively to the fabric drivenwheel 34. Each closure of theswitch 40 thus reflects the measurements of a discrete quantity of fabric produced by the knitting machine. An electrical lead from theswitch 40 may be directed by way of a brush 41 in thegear ring 13 and a slipring 42 in thehousing ring 11 to the outside of the knitting machine.

Secured on a boss on the take-up driving bracket 29 is acam lug 50 disposed for engagement with a contact arm orroller 51 of anelectrical switch 52 secured on abracket 53 carried on thehousing ring 11. Theswitch 52 is of the normally-open variety and is closed momentarily by thecam lug 50 once during each revolution of theneedle cylinder 17. Each closure of theswitch 52 thus reflects the measurement of the number of courses of knitting which are completed during each revolution of the knitting machine.

The leads from bothswitches 40 and 52 are directed to a computing device indicated generally as 60 preferably contained in acasing 61 secured to one of a plurality ofvertical standards 62 rising from thehousing ring 11 or in a similar position on the knitting machine where it may be viewed by the knitting machine operator. It is a function of the computing device continuously to combine the measurements of the fabric courses and of the quantity of fabric being produced to provide a response proportional to the yield of the fabric being produced and it may be used to display indicia representing fabric yield during operation of the machine.

Referring to FIGS. 3, 4 and illustrating thecomputing device 60, abearing 63 on thecasing 61 and abearing 64 on apartition 65 inside the casing rotatably supports asleeve 66 to which is fixed aretrograde ratchet wheel 67 and an indicatingwheel 68 having a smooth cylindrical periphery on which indicia may be marked. Astud shaft 69 carried within thesleeve 66 is fixed to thecasing 61 by means of acollar 70 and setscrews 71 and 72. Adjacent to the indicatingwheel 68, adrive ratchet wheel 73 is freely journaled on theshaft 69 and biased in a counterclockwise direction as viewed in FIG. 4 by acoil spring 74 attached to thedrive ratchet wheel 73 and to thestud shaft 69. An at rest position of the drive ratchet wheel in response to thecoil spring 74 is determined by astop pin 75 protruding from the driving ratchet wheel for engagement with anabutment pin 76 secured to the casmg.

An operative connection exists between the drivingratchet wheel 73 and thesleeve 66 and the indicatingwheel 68 whereby the sleeve and the indicating wheel will be driven in one direction by the driving ratchet wheel. To this end adrive lug 77 extends laterally from the driving ratchet wheel and is positioned to abut one side of apin 78 extending laterally from the indicating wheel. As viewed in FIG. 4, clockwise movement of the drivingratchet wheel 73 will be transmitted to thesleeve 66 and the indicatingwheel 68 by thedrive lug 77 andpin 78. Acoil spring 79 secured at one extremity to the indicatingwheel 68 and at the other extremity to theshaft 69 serves to bias thesleeve 66 and the indicatingwheel 68 toward an at-rest position as determined by engagement of thepin 78 with thedriving lug 77.

The drivingratchet wheel 73 is indexed during the operation of the knitting machine by means of adrive pawl 80 biased into engagement with the driving ratchet wheel by aspring 81 and pivoted'as at 82 to the armature or plunger 83 of anelectric solenoid 84. The solenoid is connected electrically with theswitch 52 so as to actuate thedrive pawl 80 upon each revolution of the knitting machine sensed by theswitch 52.

Secured on arock shaft 85 journaled between thecasing 61 ofcomputer 60 and thepartition 65 is aretrograde pawl 86 biased into engagement with the teeth of the drivingratchet wheel 73 by means of aspring 87 which ex-- tends between ananchor pin 88 secured to the casing and arock arm 89 secured on therock shaft 85.

the computer casing and thepartition 65. Aspring 92 extending between ananchor pin 93 on the casing and arock arm 94 fast on thesecond rock shaft 91 serves to bias the retrograde pawl into engagement with theretrograde ratchet wheel 68.

Both theretrograde pawl 90 and thedrive lug 77 when in engagement with thepin 78 serve to prevent thesleeve 66 and the indicatingwheel 68 from partaking of retrograde movement as the indicatingwheel 68 is indexed by the drivingratchet wheel 73. The indicia on the indicating Wheel are thus indexed past a window 95 (FIGS. 1 and 2) formed in the computer casing a predetermined increment for each revolution of the knitting machine, or in other words, a given increment upon each completion of that number of courses made by the machine in each revolution.

Secured on thecomputer casing 61 is an electrical solenoid of which the armature orplunger 101 is pivoted as at 102 torock arm 94 associated with theretrograde pawl 90. Thesolenoid 100 is connected electrically with theswitch 40 and is arranged when activated by closure of theswitch 40 to shift theplunger 101 to the right as viewed in FIG. 4 to release theretrograde pawl 90. Since theswitch 40 is closed only momentarily upon the measurement of each predetermined quantity of fabric, thesolenoid 100 will be activated only momentarily after which theretrograde pawl 90 under the action of thespring 92 will be returned into engagement with theretrograde ratchet wheel 67 and thearmature 101 will be shifted to the left as viewed in FIG. 4.

Apin 103 protruding from thearmature 101 slides beneath alink 104 pivoted at 105 on theretrograde pawl 86 which engages the drivingratchet wheel 73. The undersurface of thelink 104 is formed with anotch 106 which falls into engagement with thepin 103 when thearmature 101 is shifted to the right as viewed in FIG. 4 upon actuation of thesolenoid 100. When thespring 92 returns thearniature 101 to the left as viewed in FIG. 4, thepin 103 in engagement with thenotch 106 will shift theretrograde pawl 86 out of engagement with the drivingratchet wheel 73 thus releasing the driving ratchet wheel to be returned at the at-rest position by thecoil spring 74.

Since theretrograde pawl 90 will have re-engaged theretrograde ratchet wheel 67 associated with thesleeve 66 and the indicatingwheel 68 prior to release of the driving ratchet wheel '73, the indicatingwheel 68 andsleeve 66 will be maintained in the final position to which they have been indexed by the drivingratchet wheel 73 and the positions of thesleeve 66 and the indicium on the indicatingwheel 68 corresponding to such indexed position will be maintained.

Upon the first actuation of thedrive pawl 80 after each release of the drivingratchet wheel 73, acam surface 107 formed beneath thedrive pawl 80 will engage apin 108 carried by arelease lever 109 fulcrumed at 110 on the computer casing, and shift the release lever against the action of a light spring 111 upwardly beneath thelink 104. Thenotch 106 in the link will thus The retro--grade ratchet wheel 67 andsleeve 66 secured to theindi eating wheel 68 similarly cooperate with aretrograde pawl 90 secured on asecond rock shaft 91 journaled between be raised out of engagement with thepin 103 and theretrograde pawl 86 will be returned by thespring 87 into engagement with the drivingratchet wheel 73.

The cycle of operation above described will be repeated continually during the operation of the machine with a plurality of indexing pulses being imparted to the driving ratchet wheel until culminated by the alternate release of the retrograted motion pawls 9i] and 86. If the fabric being manufactured by the machine is of uniform yield the number of courses produced during the measurement of any discrete quantity of fabric will remain the same and thedrive lug 77 will be in engagement with thepin 73 whenever theretrograde pawl 90 is released. With uniform conditions, therefore, the positions ofsleeve 66 remain unchanged and the same indicium will remain in view through thewindow 95.

If, however, the fabric should gradually become more dense, i.e., comprise a greater number of courses and hence the number of stitches per unit length of fabric, a greater number of indexing pulses will occur by way of the drivingpawl 80 during each interval of fabric measurement. As a result, thelug 77 will engage and advance thepin 78 and, therefore, thesleeve 66, and the indicatingwheel 68 so as to change the indicia displayed through thewindow 95.

Should the fabric decrease in weight i.e. contain fewer courses per unit length, thelug 77 will be indexed short of engagement with thepin 78 and upon release of theretrograde pawl 90, thesleeve 66 and the indicatingwheel 68 will be returned by thecoil spring 79 until thepin 78 engages thelug 77 thus changing the sleeve position and the indicium displayed through thewindow 95.

Referring to FIG. 3, there is secured as by fasteningscrew 115 to thecasing 61 of thecomputer 60 adjacent the sleeve bearing 63 anadjustable potentiometer 116. Thepotentiometer 116, as is conventional, includes a movable contact arm 117 (see FIG. 7) which is attached to thesleeve 66 to be turned thereby.

The measurements which result in a position of thecontact arm 117 representative of fabric yield are derived from the fabric F as it is being knit and while the fabric is under the influence of a take-up device. This is advantageous, as pointed out above, in providing practically immediate corrective adjustments of thecontact arm 117 of the potentiometer. Preferably, the fabric yield measuring devices is located closely adjacent to the point at which the fabric is being manufactured. This was stated in my above cited United States Patent No. 3,099,- 142, col. 2, lines 311 and it is shown in FIGS. 1 and 2, herein, insofar aselement 36 is closely adjacent to the point at which fabric is being produced. In other words the measurement is made closely adjacent to theneedles 24 relative to the fabric take-up 30, with the resulting advantage that there is a reduction of the time lag between the time of occurrence of a variation in fabric yield and the time of correction of that variation. The yield of a fabric, however, may change when it passes from the influence of the take-up device. Moreover, different yarns recover at different rates from the tensions applied during fabric manufacture. The difference between the condition of the fabric as it is being knit and its condition after it has reached an equilbrium is, for any given fabric substantially a constant, the value of which once determined either by measurement or by experience may be included in the adjustment and design of the potentiometer and the calibration of the indicating wheel.

As illustrated in FIG. 2, the casing of thecomputing device 60 may also includeconventional counting devices 120 for recording and displaying, for instances, the total machine revolutions, or the total fabric yardage produced. These conventional counting devices may be operated by the solenoids or by other means if desired. Since such counting devices are conventional in the art, the operating means therefore are not illustrated in the accompanying drawings.

Thestandards 62 rising fromhousing ring 11 sustain a webbed ring aboveneedle cylinder 17. From thering 130 extends acentral post 131 supporting various parts of the yarn stand as is described below. Fixed relatively to the machine frame is asinker carrier ring 132 which encompasses the top of theneedle cylinder 17. Thesinker carrier ring 132 has formed or secured thereto surfaces which support sinkers (not shown) which cooperate with the needles in knitting fabric and sinker actuating cams (not shown). Further description of this portion of the sinker mechanism which is conventional is set forth in United States Patent application Serial No. 278,135 referred to hereinabove. Secured on thesinker carrier ring 132 are a multiplicity ofyarn carriers 133 arranged about the needle cylinder with one corresponding to each set of needle raising and stitchcams 26, 27. Eachyarn carrier 133 together with the appropriate sinker cams and needle earns 26, 27 for actuating the sinkers and needles to cooperate with the yarn carrier and to incorporate the delivered yarn into the knit fabric are referred to collectively as a feed. A multifeed knitting machine refers to an arrangement as illustrated in FIG. 1 in which many feeds are arranged about the needle cylinder.

Secured onpost 131 is aring 135 holding yarn packages 136. At the top ofpost 131 is abracket 137 having radial arms adapted to be fitted with unwindingeyelets 138 for the yarn through each of which a single yarn passes from its package. Abracket 139 on thepost 131 hassimilar eyelets 140 for guiding yarn to respectivestop motion devices 141 supported on abracket 142 on thepost 131. Beneath the stop motion devices areyarn tensioning devices 143 supported on abracket 144 on thepost 131 with one for each of the yarns, which tensioning devices may be of the conventional type.

A variable yarn conditioning device shown in FIGS. 1 and 6 is supported onpost 131. A pair of support rings 151 and 152 are afiixed in spaced coaxial relation bybrackets 153 secured on thepost 131. Extending between and journaled on therings 151 and 152 are identical cylindricalyarn feed rollers 154. Eachroller 154 is attached to one of a set ofidentical sprocket wheels 155. Alink chain 156 is directed about the sprocket Wheels in mesh therewith. The chain is directed between two of thesprocket wheels 155 in mesh with adrive sprocket wheel 157 fast on astud shaft 158 journaled in aplate 15? on thebracket 153 for theupper support ring 151. Also fast on thestud shaft 158 is a V-belt pulley 160. A conventional V-belt 161 is entrained on pulley and also entrained on one of the companion sheaves 162 of a variable speed V-belt pulley unit 163 carried on theplate 159. A second V-belt 164 is entrained on the other companion sheave 165 of thepulley unit 163 and extends to apulley 166 fast on ashaft 167 journaled inbrackets 168 on one of thevertical frame standards 62. By means ofbevel gears 169 on theshaft 167 and on the knittingmachine drive shaft 19, a drive is completed from theknitting machine motor 20 to theyarn feed rollers 154.

The variable speed V-belt pulley unit 163 illustrated in the drawings is designed so that the effective pitch diameters of the companion sheaves 162, 165 may be varied inversely by angular adjustment of a regulatingarm 170. A threadedshaft 171 threadedly engages astud 172 on thearm 170. Theshaft 171 is constrained in abearing bracket 173 on thesupport ring 151 bycollars 174 on the shaft. A servo-motor 175 andgear box 176 are connected to adjust theshaft 171. It will be understood that by means of themotor 175,gear box 176, and thepulley unit 163, the speed of rotation ofrollers 154 may be adjusted relatively to the speed of rotation of theneedle cylinder 17. Further description of the details of operation of apparatus designed in accordance with variableyarn conditioning device 150 may be found by reference to United States application Serial No. 278,135

referred to hereinabove. In general, theyarn conditioning device 150 may be used to apply consistent and uniform tension to yarns Y delivered to the needles. By a turning movement applied to theshaft 171 by themotor 175, the tension applied to all the yarns may be varied alike so as to influence the stitch configuration and stitch count in the resulting knit fabric during regular operation of the knitting machine to provide the desired fabric yield from the knitting machine.

The automatic control system of this invention may be an electrical system such as that shown in FIG. 7 or a mechanical system such as that shown in FIG. 8.

Referring to FIG. 7 thecontact arm 117 of theadjustable potentiometer 116 is shown attached to thesleeve 66 of thecomputing device 60.Switches 40 and 52 are shown in block form connected electrically to thecomputing device 60 and connected mechanically as described above to the knitting machine also shown in block form for convenience of illustration.Central post 131 is shown supporting the variableyarn conditioning device 150 including thebracket 153 supporting theyarn conditioning device 150 and thebelt 161 connected to drive the yarn conditioning device. Themotor 20 is directly connected to the knittingmachine drive shaft 19 connected bybevel gears 169 to theshaft 167 driving thepulley 166 which drivesbelt 164 which drives the companion sheaves 165. Thecompanion sheave 162 is connected to drivebelt 161. The regulatingarm 170 for thevariable speed drive 163 is adjusted by the threadedshaft 171 connected to be driven byservo motor 175 throughgear box 176.

Theservo motor 175 is a conventional two phase A.C. servo motor having a first winding 180 connected through acapacitor 181 to anA.C. power source 182. Thecapacitor 181 provides a phase shift of about 90 in the potential applied to theWinding 180 frompower source 182. An error signal winding 183 is connected to receive an error signal when it exists from an electrical signal comparison circuit, providing excitation of the winding 183 with the power fromsource 182. In the absence of excitation of winding 183, themotor 175 will remain at rest. The phase of the potential applied to winding 183 may lead or lag the potential applied to winding 180 and depending on the lead or lag condition will driveshaft 171 in opposite angular directions about its axis.

To provide an error signal, a secondadjustable potentiometer 184 having acontact arm 185 adapted to be adjusted manually has the ends of its windings connected to the terminals of theA.C. power source 182. Thecontact arm 185 is adjusted to a position providing a reference potential which may be calibrated with an index thereon and indicia on a fixed plate to indicate a predetermined desired fabric yield for each position ofcontact arm 185. The actual yield is indicated by the position ofsleeve 66, andcontact arm 117 ofpotentiometer 116 which likewise has the ends-of its windings connected to the terminals of theA.C. power source 182. Thecontact arms 185 and 117 are connected as inputs to anamplifier 186, preferably through a minimumpotential signal circuit 187. The signal supplied to thecircuit 187 is an error signal indicating the present difference between the actual fabric yield represented by the signal oncontact 117 and the desired yield or reference signal oncontact 185. The relative phase of the signal applied to thecircuit 187 with respect to the phase on winding 180 depends upon which one of the signals oncontacts 117, 185 exceeds the other with respect to a reference potential for instance, at the junction ofsource 182 andcapacitor 181. Theminimum signal circuit 187 is preferably included in the circuit to prevent very small error signals from causing response of the system and attendant hunting by theservo motor 175 in an attempt to reduce the error signal exactly to zero. This minimum potential signal circuit may be omitted if desired. The output ofamplifier 186 is applied to the winding 183 of theservo motor 175 preferably through a maximumtime delay circuit 188 permittingservo motor 175 to be adjusted incrementally and thereby eliminating sharp readjustments in fabric yield which might cause striations in the fabric. However, the maximumtime delay circuit 188 may be omitted from the system if desired. The maximum-time delay circuit may comprise a conventional time-delay relay or the like.

In operation, if the fabric yield increases, thecomputing device 60 is driven to a higherposition rotating shaft 66 further clockwise as viewed from FIG. 4 or will movecontact arm 117 counterclockwise as viewed in FIG. 7. Assuming that no difference in potential had existed betweenarm 117 andarm 185 prior to that time, there will be an error signal produced. In response thereto, themotor 175 will be driven in such a direction as to adjust theshaft 171, the variable speed drive, and the yarn conditioning device to reduce the yield, thereby restoring the fabricyield computing device 60,sleeve 66 andarm 117 to their original positions. At such time, the error signal will be reduced to zero or to such a small value that the motor will stop.

If the fabric yield decreases, thearm 117 will be driven clockwise as viewed in FIG. 7 producing an error signal of opposite phase to that for counterclockwise rotation, and themotor 175 will be rotated in the opposite direction, to reduce yarn tension untilarm 117 is returned to provide minimum or zero error signal, when the desired fabric yield is obtained.

Thesecond potentiometer 184 providing the reference potential together with the minimumpotential error circuit 187, theamplifier 186 and the minimumtime delay circuit 188 may be housed in acasing 21%) attached to aleg 12 of the knitting machine as illustrated in FIG. 1. Thecasing 210 is preferably located a convenient height for operator influence of aknob 211 thereon by which the potentiometer contact arm may be adjusted.

If desired, theknob 211 can be adjusted continuously to provide a programmed variation in yield or it can be changed at various intervals as desired. The overall operation of the system when a constant yield is desired can be obtained without any supervision of the fabric yield or manual adjustment of the mechanisms controlling the formation of the stitches after the machine has been initially adjusted for operation.

Referring to FIG. 8, a control system similar in result to that described in connection with FIG. 7 is shown but employing a mechanical system of error detection. As can be seen, the elements of the system fromshaft 171 through the knitting machine to thesleeve 66 are identical to those shown in FIG. 7. In the modification illustrated in FIG. 8, however, a earn 190 is adjustably attached to the end ofsleeve 66 by means of acollar 191 fitting over the end ofsleeve 66 and pinned thereto and ahollow portion 192 of the upper end ofcollar 191 adapted to receive and mate with the lower end of thecam 190 adjustably affixed thereto by means of setscrew 193.

The position of thecam 190 on thesleeve 66 may be adjusted by releasing setscrew 193 and rotating thecam 190 in thehollow portion 192.Indicia 194, 195 are preferably provided on thecam 190 and on thecollar 191 to indicate the relative angular position of thecam 190 with respect to thesleeve 66.

Aplate 197 is rotatably supported relatively to the knitting machine by afulcrum screw 198 and is biased byspring 199 to hold acam follower surface 200 on one end thereof in contact with thecamming surface 201 of thecam 190. Amotor 202 having a single direction of rotation is afiixed to plate 197 at the opposite end thereof. Afriction drive wheel 203 is attached to the shaft of themotor 202 and is engageable with friction drivenwheels 204, 205 for respective angular positions ofplate 197 aboutsupport screw 198.

The friction drivenwheel 204 is directly connected to theshaft 171 permitting adjustment of the position of regulatingarm 170 in one direction when thefriction drive wheel 203 engages the friction drivenwheel 204. Friction drivenwheel 205 is connected to theshaft 171 by way ofgear wheels 206 and 207 and acountershaft 208 so as to driveshaft 171 and shift the regulatingarm 170 in the opposite direction when thefriction drive wheel 203 engages the friction drivenwheel 205. Thecam surface 201 is designed to control the position of the friction drive wheel with respect to the friction drivenWheels 204, 205 in response to rotation ofsleeve 66. When thecam surface 201 raises the cam follower surface 200 a predetermined amount, the drivenfriction wheel 205 will be driven byfriction drive wheel 203 and whencam surface 201 lowers the cam follower surface 200 a predetermined amount, drivenfriction wheel 204 will be driven byfriction drive wheel 203. For intermediate positions of thecam follower surface 201 thefriction drive wheel 203 will remain out of engagement with both drivenwheels 204 and 205 and theshaft 171 Will be at rest maintaining adjustment of theyarn conditioning device 150 until such time as rotation ofsleeve 66 causes the system to readjust in response to variations in the fabric yield of the knitting machine.

Having thus described the nature of this invention What I claim herein is:

1. In a circular independent needle knitting machine adapted to concatenate yarn into a knit fabric having an identifiable characteristic, the combination which includes yarn conditioning means associated with said knitting machine for varying said characteristic of the knit fabric during operation of the machine, means for measuring said characteristic of the knit fabric during operation of the knitting machine and providing a measurement output varying in quantity as a function of said characteristic of the knit fabric, and control means operable in response to deviation of said measurement output from a selected norm for providing adjustment of said yarn conditioning means in proportion to the quantity of said deviation in a manner tending to reduce said deviation from said norm.

2. In a circular knitting machine having a plurality of feeds, the combination which includes, yarn conditioning means associated with said knitting machine for delivering yarn to each of said feeds in a manner influencing a characteristic of the resulting knit fabric, means for measuring said characteristic of the knit fabric during operation of the knitting machine and providing a measurement output varying in quantity as a function of said characteristic of the knit fabric and control means operable in response to deviation of said measurement output from a selected norm for providing adjustment of said yarn conditioning means in proportion to the quantity of said deviation in a manner tending to reduce said deviation from said norm.

3. In a circular knitting machine, means for measuring the angular displacement of said circular knitting machine during operation thereof, means for simultaneously measuring the linear quantity of fabric produced on said knitting machine, a fabric yield computing device operated by said measuring means and providing an output as a function of the computed yield, and a control means operable in response to deviation of said output from a selected norm for influencing the operation of said knitting machine in a manner tending to produce a knit fabric having a uniform yield.

4. In a circular independent needle knitting machine adapted to concatenate yarn into a knit fabric having an identifiable characteristic, the combination which includes means for measuring said characteristic of the knit fabric during operation of the knitting machine and providing a measurement output varying in quantity as a function of said characteristic of the knit fabric, and a reversible knitting machine corrective motor operable in one direction in response to deviation of said measurement output above a selected norm and in the opposite direction in response to deviation of said measurement output below said selected norm said motor being regulated by an input varying as a function of the quantity of said deviation from said selected norm.

5. In a circular independent needle knitting machine adapted to concatenate yarn into a knit fabric having an identifiable characteristic, the combination which includes yarn conditioning means associated with said knitting machine for varying said characteristic of the knit fabric during operation of the machine, means for measuring said characteristic of the knit fabric during operation of the knitting machine and providing a measurement output as a function of said characteristic of the knit fabric, means providing a reference output, control means operable in response to deviation of said measurement output from said reference output for providing adjustment of said yarn conditioning means in a manner tending to reduce the deviation from said norm, and means for varying said reference output during operation of said knitting machine.

6. In a circular knitting machine having a plurality of feeds, the combination which includes, yarn conditioning means associated with said knitting machine for delivering yarn to each of said feeds in a manner influencing a characteristic of the resulting knit fabric, means for measuring said characteristic of the knit fabric during operation of the knitting machine and providing a measurement output as a function of said characteristic of the knit fabric, means providing a reference output, control means operable in response to deviation of said measurement output from said reference output for providing adjustment of said yarn conditioning means in a manner tending to reduce the deviation from said norm, and means for varying said reference output during operation of said knitting machine.

7. In a circular knitting machine, means for measuring the angular displacement of said circular knitting machine during operation thereof, means for simultaneously measuring the linear quantity of fabric produced on said knitting machine, a fabric yield computing device operated by said measuring means and providing a computed output as a function of the computed yield, means providing a reference output, a control means operable in response to deviation of said computed output from said reference output for influencing the operation of said knitting machine in a manner tending to produce a knit fabric having a predetermined yield, and means for varying said reference output during operation of said knitting machine to provide for a predetermined yield variation along the length of the resulting knit fabric.

8. In a machine for concatenating fibers to form a fabric web having an identifiable characteristic, the combination which includes regulating means associated with said machine for varying said characteristic of the fabric Web during operation of the machine, means for measuring said characteristic of the fabric during operation of the machine and providing a measurement output varying in quantity as a function of said characteristic of the fabric web, and control means operable in response to deviation of said measurement output from a selected norm for providing adjustment of said regulating means in proportion to the quantity of said deviation in a manner tending to reduce said deviation from said norm.

9. In a machine for concatenating fibers to form a fabric web having an identifiable characteristic, in combination regulating means associated with said machine for varying said characteristic of the fabric web during the operation of the machine, means for measuring said characteristic of the fabric web during operation of the machine and providing a measurement output varying in quantity as a function of said characteristic of the fabric web formed on said machine, means for providing a selected reference relatively to said measurement output, and means responsive to differences between said measurement output and said reference for operating said regulating means in proportion to the corresponding quantity of each of said differences in a manner tending to reduce the said differences.

10. In a machine for concatenating fibers to produce a fabric, a first means for measuring the fiber courses being incorporated into said fabric during operation of the machine, a second means for measuring the linear quantity of fabric produced during the operation of the machine, a fabric yield computing device operated by said first and second measuring means, means for providing an electrical reference signal, means operated by said computer to provide an electrical indicator signal, means for comparison between said indicator and reference signals, and trically to produce an error signal in response to the comparision between said indicator and reference sginals, and means operated in response to said error signal for adjusting said machine to reduce the amplitude of said error signal.

11. In a machine for concatenating fibers to produce a fabric, means for measuring a characteristic of the fabric produced during operation of the machine, said means producing an output in response thereto, control means responsive to the output of said measuring means providing a signal for predetermined outputs from said measuring means, means operating in response to said signal for adjusting said machine to provide substantially a predetermined output from said measuring means.

12. In a machine for concatenating fibers to produce a fabric, means for computing a characteristic of the fabric produced during the operation of the machine, means for providing a first electrical signal, means responsive to said computer for providing a second electrical signal, means for providing a third electrical signal in response to said first and second electrical signals, and means operable in response to said third signal for adjusting the condition of operation of said machine in such manner as to vary the magnitude of said second signal in a direction tending to reduce said third signal.

13. A multi-feed knitting machine having knitting instrumentalities, actuating means for operating said knitting instrumentalities, means for supporting a plurality of yarn supplies relatively to said knitting machine, means for furnishing yarns from said yarn supplies to said knitting instrumentalities comprising a plurality of cylindrical yarn feed rollers of equal diameter, means for directing yarn between each of said yarn supplies and said knitting instrumentalities into engagement with each of said yarn feeding rollers in seriatim, means for imparting turning movement to each of said yarn feeding rollers including a common drive element operatively engaging each of said yarn feed rollers, drive means operatively connecting said common drive element with said actuating means for said knitting instrumentalities, speed control means in said drive means adjustable for selectively varying the turning movement of said yarn feed rollers relatively to the operation of said knitting instrumentalities, means for measuring the angular displacement of said circular knitting machine during operation thereof, means for simultaneously measuring the linear quantity of fabric produced on said knitting machine, a fabric yield computing device operated by said measuring means and providing an output as a function of the computed yield, and a control means operable in response to deviation of said output from a selected norm for influencing the operation of said means for adjusting said speed control means of said yarn furnishing means in a manner tending to produce a knit fabric having a uniform yield.

14. In a circular knitting machine having a plurality of feeds, the combination which includes, yarn conditioning means associated with said knitting machine for delivering yarn to each of said feeds in a manner influencing a characteristic of the resulting knit fabric,

measuring means for providing response to the formation of each predetermined number of courses of knitting by said machine, measuring means for providing response to each predetermined length of fabric knit by said machine, a fabric yield computing device comprising a shiftable indexing member, means for defining an at-rest position of said indexing member, means for biasing said indexing member towards said at-rest position, a ratchet associated with said indexing member, pawl means cooperating with said ratchet for imparting successive increments of movement to said indexing member in one direction from said at-rest position one increment upon each response of one of said measuring means, a retrograde pawl cooperating with said ratchet, a fabric yield output member shiftably supported adjacent to said indexing member for movement towards and away from the at-rest position of said indexing member, means for biasing said output member toward said at-rest position, an abutment on said indexing member engageable with said output member in a predetermined relative position of said members and effective to shift said output member along with said indexing member in said one direction from said atrest position, retrograde brake means associated with said output member, means effective upon each response of said other measuring means for effecting in seriatim release of the retrograde brake means of said output member, reengagement of said retrograde brake means, and release of the retrograde pawl of said indexing member, and means responsive to the position of said output member for providing adjustment of said yarn conditioning means in a manner tending to produce a knit fabric having a uniform yield.

15. A multi-feed knitting machine having knitting instrumentalities, actuating means for operating said knitting instrumentalities, means for supporting a plurality of yarn supplies relatively to said knitting machine, means for furnishing yarns from said yarn supplies to said knitting instrumentalities comprising a plurality of cylindrical yarn feed rollers of equal diameter, means for directing yarn between each of said yarn supplies and said knitting instrumentalities into engagement with each of said yarn feeding rollers in seriatim, means for imparting turning movement to each of said yarn feeding rollers including a common drive element operatively engaging each of said yarn feed rollers, drive means operatively connecting said common drive element with said actuating means for said knitting instrumentalities, speed control means in said drive means adjustable for selectively varying the turning movement of said yarn feed rollers relatively to the operation of said knitting instrumentalities, measuring means for providing response to the formation of each predetermined number of courses of knitting by said machine, measuring means for providing response to each predetermined length of fabric knit by said machine, a fabric yield computing device comprising a shiftable indexing member, means for defining an at-rest position of said indexing member, means for biasing said indexing member towards said at-rest position, a ratchet associated with said indexing member, pawl means cooperating with said ratched for imparting successive increments of movement to said indexing member in one direction from said at-rest position one increment upon each response of one of said measuring means, a retrograde pawl cooperating with said ratchet, a fabric yield output member shiftably supported adjacent to said indexing member for movement towards and away from the at-rest position of said indexing member, means for biasing said output member toward said at-rest position, an abutment on said indexing member engageable with said output member in a predetermined relative position of said members and effective to shift said output member along with said indexing member in said one direction from said at-rest position, retrograde brake means associated with said output member, means effective upon each response of said other measuring means for effecting in seriatim release of the retrograde brake means of said output member reengagement of said retrograde brake means, and release of the retrograde pawl of said indexing member, means for adjusting said speed control means, and means responsive in a predetermined manner to the position of said output member for providing actuation of said means for adjusting said speed control means in a manner tending to produce knit fabric having a uniform yield.

16. Apparatus in accordance withclaim 3, wherein said means for measuring the linear quantity of fabric produced on said knitting machine measures the linear quantity of fabric produced at a point closely adjacent to the point at which said fabric is being produced.

References Cited by the Examiner UNITED STATESPATENTS FOREIGN PATENTS 4/ 1957 Great Britain.

DONALD W. PARKER, Primary Examiner.

RUSSELL C. MADER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,225,570 December 28, 1965 Lester Mishcon It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 11,lines 15 to 17, strike out "comparison between said indicator and reference signals, and trically" and insert instead comparing said reference signal and said indicator signal electrically same column ll,line 18, for "sginals" read signals Signed and sealed this 6th day of December 1966.

( L) Amumn ERNEST w. SWIDER EDWARD J. BRENNEIt Attesting Officer Commissioner of Patents

Claims (1)

1. IN A CIRCULAR INDEPENDENT NEEDLE KNITTING MACHINE ADAPTED TO CONCATENATE YARN INTO A KNIT FABRIC HAVING AN IDENTIFIABLE CHARACTERISTIC, THE COMBINATION WHICH INCLUDES YARN CONDITIONING MEANS ASSOCIATED WITH SAID KNITTING MACHINE FOR VARYING SAID CHARACTERISTIC OF THE KNIT FABRIC DURING OPERATION OF THE MACHINE, MEANS FOR MEASURING SAID CHARACTERISTIC OF THE KNIT FABRIC DURING OPERATION OF THE KNITTING MACHINE AND PROVIDING A MEASUREMENT OUTPUT VARYING IN QUANTITY AS A FUNCTION OF SAID CHARACTERISTIC OF THE KNIT FABRIC, AND CONTROL MEANS OPERABLE IN RESPONSE TO DEVIATION OF SAID MEASUREMENT OUTPUT FROM A SELECTED NORM FOR PROVIDING ADJUSTMENT OF SAID YARN CONDITIONING MEANS IN PROPORTION TO THE QUANTITY OF SAID DEVIATION IN A MANNER TENDING TO REDUCE SAID DEVIATION FROM SAID NORM.

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