US3225570A

US3225570A - Automatic stitch control

Info

Publication number: US3225570A
Application number: US291011A
Authority: US
Inventors: Mishcon Lester
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1963-06-27
Filing date: 1963-06-27
Publication date: 1965-12-28
Anticipated expiration: 1982-12-28
Also published as: GB1027256A; DE1585327A1

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 along line 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 with gear teeth 15 and an upstanding flange 16 to which a needlecylinder 17 is secured. The gear teeth 15 mesh with a' pinion 18 fast on a shaft 19 which is driven by an electric motor 20 by way of a clutch device 21. The gear ring 13 is constrained rotatably in the housing ring ll'by a retaining ring 22 secured to the housing ring.

The outer wall of the needle cylinder 17 is formed' with evenly spaced vertical slots 23 each slot slidably ac' commodating a latch needle 24 formed with a butt 25. As the needle cylinder is rotated, the needle butts are successively influenced alternately by needle raising cams 26 carried by the retaining ring 20 and then by stitch cams 27 carried by a section block 28 on the cam retaining ring 22. Each set of

cams

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 the

earns

26 and 27.

Fast on the gear ring 13 so as to rotate with the needle 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 a support frame 32 carrying a stud shaft 33 on which is journaled a fabric driven wheel 34 provided peripherally with fabric engaging pins. Secured caxially with the wheel 34 is a sprocket wheel 35 engaging an endless 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 the links 38 of the chain 36 is formed higher than the remainder of the links so as to provide a cam surface engageable with a contact arm or roller 39 of an electrical switch 40 secured on the take-up driving bracket 29 adjacent to the support frame 32. The switch 40 is of the normally-open variety and is closed momentarily by the cam link 38 upon the passage of a predetermined quantity of fabric relatively to the fabric driven wheel 34. Each closure of the switch 40 thus reflects the measurements of a discrete quantity of fabric produced by the knitting machine. An electrical lead from the switch 40 may be directed by way of a brush 41 in the gear ring 13 and a slipring 42 in the housing ring 11 to the outside of the knitting machine.

Secured on a boss on the take-up driving bracket 29 is a cam lug 50 disposed for engagement with a contact arm or roller 51 of an electrical switch 52 secured on a bracket 53 carried on the housing ring 11. The switch 52 is of the normally-open variety and is closed momentarily by the cam lug 50 once during each revolution of the needle cylinder 17. Each closure of the switch 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 both

switches

40 and 52 are directed to a computing device indicated generally as 60 preferably contained in a casing 61 secured to one of a plurality of vertical standards 62 rising from the housing 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 the computing device 60, a bearing 63 on the casing 61 and a bearing 64 on a partition 65 inside the casing rotatably supports a sleeve 66 to which is fixed a retrograde ratchet wheel 67 and an indicating wheel 68 having a smooth cylindrical periphery on which indicia may be marked. A stud shaft 69 carried within the sleeve 66 is fixed to the casing 61 by means of a collar 70 and set

screws

71 and 72. Adjacent to the indicating wheel 68, a drive ratchet wheel 73 is freely journaled on the shaft 69 and biased in a counterclockwise direction as viewed in FIG. 4 by a coil spring 74 attached to the drive ratchet wheel 73 and to the stud shaft 69. An at rest position of the drive ratchet wheel in response to the coil spring 74 is determined by a stop pin 75 protruding from the driving ratchet wheel for engagement with an abutment pin 76 secured to the casmg.

An operative connection exists between the driving ratchet wheel 73 and the sleeve 66 and the indicating wheel 68 whereby the sleeve and the indicating wheel will be driven in one direction by the driving ratchet wheel. To this end a drive lug 77 extends laterally from the driving ratchet wheel and is positioned to abut one side of a pin 78 extending laterally from the indicating wheel. As viewed in FIG. 4, clockwise movement of the driving ratchet wheel 73 will be transmitted to the sleeve 66 and the indicating wheel 68 by the drive lug 77 and pin 78. A coil spring 79 secured at one extremity to the indicating wheel 68 and at the other extremity to the shaft 69 serves to bias the sleeve 66 and the indicating wheel 68 toward an at-rest position as determined by engagement of the pin 78 with the driving lug 77.

The driving ratchet wheel 73 is indexed during the operation of the knitting machine by means of a drive pawl 80 biased into engagement with the driving ratchet wheel by a spring 81 and pivoted'as at 82 to the armature or plunger 83 of an electric solenoid 84. The solenoid is connected electrically with the switch 52 so as to actuate the drive pawl 80 upon each revolution of the knitting machine sensed by the switch 52.

Secured on a rock shaft 85 journaled between the casing 61 of computer 60 and the partition 65 is a retrograde pawl 86 biased into engagement with the teeth of the driving ratchet wheel 73 by means of a spring 87 which ex-- tends between an anchor pin 88 secured to the casing and a rock arm 89 secured on the rock shaft 85.

the computer casing and the partition 65. A spring 92 extending between an anchor pin 93 on the casing and a rock arm 94 fast on the second rock shaft 91 serves to bias the retrograde pawl into engagement with the retrograde ratchet wheel 68.

Both the retrograde pawl 90 and the drive lug 77 when in engagement with the pin 78 serve to prevent the sleeve 66 and the indicating wheel 68 from partaking of retrograde movement as the indicating wheel 68 is indexed by the driving ratchet 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 the computer casing 61 is an electrical solenoid of which the armature or plunger 101 is pivoted as at 102 to rock arm 94 associated with the retrograde pawl 90. The solenoid 100 is connected electrically with the switch 40 and is arranged when activated by closure of the switch 40 to shift the plunger 101 to the right as viewed in FIG. 4 to release the retrograde pawl 90. Since the switch 40 is closed only momentarily upon the measurement of each predetermined quantity of fabric, the solenoid 100 will be activated only momentarily after which the retrograde pawl 90 under the action of the spring 92 will be returned into engagement with the retrograde ratchet wheel 67 and the armature 101 will be shifted to the left as viewed in FIG. 4.

A pin 103 protruding from the armature 101 slides beneath a link 104 pivoted at 105 on the retrograde pawl 86 which engages the driving ratchet wheel 73. The undersurface of the link 104 is formed with a notch 106 which falls into engagement with the pin 103 when the armature 101 is shifted to the right as viewed in FIG. 4 upon actuation of the solenoid 100. When the spring 92 returns the arniature 101 to the left as viewed in FIG. 4, the pin 103 in engagement with the notch 106 will shift the retrograde pawl 86 out of engagement with the driving ratchet wheel 73 thus releasing the driving ratchet wheel to be returned at the at-rest position by the coil spring 74.

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

Upon the first actuation of the drive pawl 80 after each release of the driving ratchet wheel 73, a cam surface 107 formed beneath the drive pawl 80 will engage a pin 108 carried by a release lever 109 fulcrumed at 110 on the computer casing, and shift the release lever against the action of a light spring 111 upwardly beneath the link 104. The notch 106 in the link will thus The retro-- grade ratchet wheel 67 and sleeve 66 secured to the indi eating wheel 68 similarly cooperate with a retrograde pawl 90 secured on a second rock shaft 91 journaled between be raised out of engagement with the pin 103 and the retrograde pawl 86 will be returned by the spring 87 into engagement with the driving ratchet 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 the drive lug 77 will be in engagement with the pin 73 whenever the retrograde pawl 90 is released. With uniform conditions, therefore, the positions of sleeve 66 remain unchanged and the same indicium will remain in view through the window 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 driving pawl 80 during each interval of fabric measurement. As a result, the lug 77 will engage and advance the pin 78 and, therefore, the sleeve 66, and the indicating wheel 68 so as to change the indicia displayed through the window 95.

Should the fabric decrease in weight i.e. contain fewer courses per unit length, the lug 77 will be indexed short of engagement with the pin 78 and upon release of the retrograde pawl 90, the sleeve 66 and the indicating wheel 68 will be returned by the coil spring 79 until the pin 78 engages the lug 77 thus changing the sleeve position and the indicium displayed through the window 95.

Referring to FIG. 3, there is secured as by fastening screw 115 to the casing 61 of the computer 60 adjacent the sleeve bearing 63 an adjustable potentiometer 116. The potentiometer 116, as is conventional, includes a movable contact arm 117 (see FIG. 7) which is attached to the sleeve 66 to be turned thereby.

The measurements which result in a position of the contact 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 the contact 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 as element 36 is closely adjacent to the point at which fabric is being produced. In other words the measurement is made closely adjacent to the needles 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 the computing device 60 may also include conventional 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.

The standards 62 rising from housing ring 11 sustain a webbed ring above needle cylinder 17. From the ring 130 extends a central post 131 supporting various parts of the yarn stand as is described below. Fixed relatively to the machine frame is a sinker carrier ring 132 which encompasses the top of the needle cylinder 17. The sinker 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 the sinker carrier ring 132 are a multiplicity of yarn carriers 133 arranged about the needle cylinder with one corresponding to each set of needle raising and stitch

cams

26, 27. Each yarn 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 on post 131 is a ring 135 holding yarn packages 136. At the top of post 131 is a bracket 137 having radial arms adapted to be fitted with unwinding eyelets 138 for the yarn through each of which a single yarn passes from its package. A bracket 139 on the post 131 has similar eyelets 140 for guiding yarn to respective stop motion devices 141 supported on a bracket 142 on the post 131. Beneath the stop motion devices are yarn tensioning devices 143 supported on a bracket 144 on the post 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 on post 131. A pair of support rings 151 and 152 are afiixed in spaced coaxial relation by brackets 153 secured on the post 131. Extending between and journaled on the

rings

151 and 152 are identical cylindrical yarn feed rollers 154. Each roller 154 is attached to one of a set of identical sprocket wheels 155. A link chain 156 is directed about the sprocket Wheels in mesh therewith. The chain is directed between two of the sprocket wheels 155 in mesh with a drive sprocket wheel 157 fast on a stud shaft 158 journaled in a plate 15? on the bracket 153 for the upper support ring 151. Also fast on the stud 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 the plate 159. A second V-belt 164 is entrained on the other companion sheave 165 of the pulley unit 163 and extends to a pulley 166 fast on a shaft 167 journaled in brackets 168 on one of the vertical frame standards 62. By means of bevel gears 169 on the shaft 167 and on the knitting machine drive shaft 19, a drive is completed from the knitting machine motor 20 to the yarn 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 regulating arm 170. A threaded shaft 171 threadedly engages a stud 172 on the arm 170. The shaft 171 is constrained in a bearing bracket 173 on the support ring 151 by collars 174 on the shaft. A servo-motor 175 and gear box 176 are connected to adjust the shaft 171. It will be understood that by means of the motor 175, gear box 176, and the pulley unit 163, the speed of rotation of rollers 154 may be adjusted relatively to the speed of rotation of the needle cylinder 17. Further description of the details of operation of apparatus designed in accordance with variable yarn conditioning device 150 may be found by reference to United States application Serial No. 278,135

referred to hereinabove. In general, the yarn 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 the shaft 171 by the motor 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 the contact arm 117 of the adjustable potentiometer 116 is shown attached to the sleeve 66 of the computing device 60.

Switches

40 and 52 are shown in block form connected electrically to the computing 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 variable yarn conditioning device 150 including the bracket 153 supporting the yarn conditioning device 150 and the belt 161 connected to drive the yarn conditioning device. The motor 20 is directly connected to the knitting machine drive shaft 19 connected by bevel gears 169 to the shaft 167 driving the pulley 166 which drives belt 164 which drives the companion sheaves 165. The companion sheave 162 is connected to drive belt 161. The regulating arm 170 for the variable speed drive 163 is adjusted by the threaded shaft 171 connected to be driven by servo motor 175 through gear box 176.

The servo motor 175 is a conventional two phase A.C. servo motor having a first winding 180 connected through a capacitor 181 to an A.C. power source 182. The capacitor 181 provides a phase shift of about 90 in the potential applied to the Winding 180 from power 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 from source 182. In the absence of excitation of winding 183, the motor 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 drive shaft 171 in opposite angular directions about its axis.

To provide an error signal, a second adjustable potentiometer 184 having a contact arm 185 adapted to be adjusted manually has the ends of its windings connected to the terminals of the A.C. power source 182. The contact 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 of contact arm 185. The actual yield is indicated by the position of sleeve 66, and contact arm 117 of potentiometer 116 which likewise has the ends-of its windings connected to the terminals of the A.C. power source 182. The

contact arms

185 and 117 are connected as inputs to an amplifier 186, preferably through a minimum potential signal circuit 187. The signal supplied to the circuit 187 is an error signal indicating the present difference between the actual fabric yield represented by the signal on contact 117 and the desired yield or reference signal on contact 185. The relative phase of the signal applied to the circuit 187 with respect to the phase on winding 180 depends upon which one of the signals on

contacts

117, 185 exceeds the other with respect to a reference potential for instance, at the junction of source 182 and capacitor 181. The minimum 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 the servo 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 of amplifier 186 is applied to the winding 183 of the servo motor 175 preferably through a maximum time delay circuit 188 permitting servo motor 175 to be adjusted incrementally and thereby eliminating sharp readjustments in fabric yield which might cause striations in the fabric. However, the maximum time 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, the computing device 60 is driven to a higher position rotating shaft 66 further clockwise as viewed from FIG. 4 or will move contact arm 117 counterclockwise as viewed in FIG. 7. Assuming that no difference in potential had existed between arm 117 and arm 185 prior to that time, there will be an error signal produced. In response thereto, the motor 175 will be driven in such a direction as to adjust the shaft 171, the variable speed drive, and the yarn conditioning device to reduce the yield, thereby restoring the fabric yield computing device 60, sleeve 66 and arm 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, the arm 117 will be driven clockwise as viewed in FIG. 7 producing an error signal of opposite phase to that for counterclockwise rotation, and the motor 175 will be rotated in the opposite direction, to reduce yarn tension until arm 117 is returned to provide minimum or zero error signal, when the desired fabric yield is obtained.

The second potentiometer 184 providing the reference potential together with the minimum potential error circuit 187, the amplifier 186 and the minimum time delay circuit 188 may be housed in a casing 21%) attached to a leg 12 of the knitting machine as illustrated in FIG. 1. The casing 210 is preferably located a convenient height for operator influence of a knob 211 thereon by which the potentiometer contact arm may be adjusted.

If desired, the knob 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 from shaft 171 through the knitting machine to the sleeve 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 of sleeve 66 by means of a collar 191 fitting over the end of sleeve 66 and pinned thereto and a hollow portion 192 of the upper end of collar 191 adapted to receive and mate with the lower end of the cam 190 adjustably affixed thereto by means of set screw 193.

The position of the cam 190 on the sleeve 66 may be adjusted by releasing set screw 193 and rotating the cam 190 in the hollow portion 192.

Indicia

194, 195 are preferably provided on the cam 190 and on the collar 191 to indicate the relative angular position of the cam 190 with respect to the sleeve 66.

A plate 197 is rotatably supported relatively to the knitting machine by a fulcrum screw 198 and is biased by spring 199 to hold a cam follower surface 200 on one end thereof in contact with the camming surface 201 of the cam 190. A motor 202 having a single direction of rotation is afiixed to plate 197 at the opposite end thereof. A friction drive wheel 203 is attached to the shaft of the motor 202 and is engageable with friction driven

wheels

204, 205 for respective angular positions of plate 197 about support screw 198.

The friction driven wheel 204 is directly connected to the shaft 171 permitting adjustment of the position of regulating arm 170 in one direction when the friction drive wheel 203 engages the friction driven wheel 204. Friction driven wheel 205 is connected to the shaft 171 by way of

gear wheels

206 and 207 and a countershaft 208 so as to drive shaft 171 and shift the regulating arm 170 in the opposite direction when the friction drive wheel 203 engages the friction driven wheel 205. The cam surface 201 is designed to control the position of the friction drive wheel with respect to the friction driven

Wheels

204, 205 in response to rotation of sleeve 66. When the cam surface 201 raises the cam follower surface 200 a predetermined amount, the driven friction wheel 205 will be driven by friction drive wheel 203 and when cam surface 201 lowers the cam follower surface 200 a predetermined amount, driven friction wheel 204 will be driven by friction drive wheel 203. For intermediate positions of the cam follower surface 201 the friction drive wheel 203 will remain out of engagement with both driven

wheels

204 and 205 and the shaft 171 Will be at rest maintaining adjustment of the yarn conditioning device 150 until such time as rotation of sleeve 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 with claim 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 STATES PATENTS 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