US3831402A

US3831402A - Knitting machine encoder

Info

Publication number: US3831402A
Application number: US00192984A
Authority: US
Inventors: R Schuman
Original assignee: Warner and Swasey Co
Current assignee: MAYER WILDMAN INDUSTRIES Inc; Warner and Swasey Co
Priority date: 1971-10-27
Filing date: 1971-10-27
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27
Also published as: FR2158997A5; DE2252382A1; IT969947B; JPS4850057A; GB1403414A; BE790612A

Abstract

An improved knitting machine includes an encoder which provides signals which vary with variations in the relative position of a needle cylinder and associated feeders. The encoder includes code tracks for providing binary coded needle count signals, feeder count signals, and revolution count signals. A control system receives these binary coded signals and effects the knitting of a selected one of a plurality of patterns. A pattern selector switch is operable to vary the selected pattern.

Description

United States Patent [191 Schuman Aug. 27, 1974 1 KNITTING MACHINE ENCODER [75] Inventor: Ralph H. Schuman, Euclid, Ohio [73] Assignee: The Warner and Swasey Company,

Cuyahoga County, Ohio [22] Filed: Oct. 27, 1971 [21 Appl. No.: 192,984

[52] US. Cl 613/50 R, 250/210, 250/233 [51] int. Cl D041) 15/78 [58] Field of Search... 66/50 R, 50 A, 50 B, 154 A,

[56] References Cited UNITED STATES PATENTS 1l/1965 Frank 250/210 X 3,218,626 11/1965 Schuman 250/210 X 3,487,400 12/1969 Ludewig, Jr. et a1. 250/233 X FOREIGN PATENTS OR APPLICATIONS 1,961,102 9/1971 Germany 66/50 R 1,521,451 3/1968 France 66/50 R 1,522,413 3/1968 France 66/50 R 1,930,522 1/1970 Germany 66/154 A 1,961,021 6/1971 Germany 66/50 R 1,194,731 6/ 1970 Great Britain 66/25 Primary ExaminerWm. Carter Reynolds ABSTRACT An improved knitting machine includes an encoder which provides signals which vary with variations in the relative position of a needle cylinder and associated feeders. The encoder includes code tracks for providing binary coded needle count signals, feeder count signals, and revolution count signals. A control system receives these binary coded signals and effects the knitting of a selected one of a plurality of patterns. A pattern selector switch is operable to vary the selected pattern.

5 Claims, 7 Drawing Figures PATENIE U A1182 7 I974 SIlEHlBF 5 PAIENTEU AUG 2 71974 smears Y KNITTING MACHINE ENCODER BACKGROUND OF THE INVENTION The present invention pertains generally to code converters, and more particularly to optical shaft encoders.

Optical shaft encoders have been known and used in a variety of applications for several years. The most common use of optical shaft encoders is to provide digital position feedback signals for servom'echanism positioning systems, or to provide digital position signals for a digital position readout and display system.

Most optical shaft encoders generate binary arithmetic outputs or Gray code outputs. There are also encoders that generate output signals that represent some mathematical function of the input shaft rotation, e.g. the sine of the angle of rotation. None of the known encoders, however, were suitable for providing the required positional signals for an electronically controlled circular knitting machine.

The knitting machine control system with which the present encoder is intended to operate is described in application Ser. No. 193,047 filed Oct. 27, 1971 in the name of Paul Christiansen entitled Knitting Machine Controls and assigned to the assignee of the present application. Briefly, the control provides means for assembling pattern data in a memory device, such as a magnetic disc, means for retrieving the stored information from memory, and means for directing it to the proper electromagnetic acutators at the several feeders to cause the proper needles to knit or non-knit as required to knit the pattern represented by the stored pattern data. The encoder of the present invention provides the knitting machine control with position signals to enable the control to retrieve the proper portion of pattern data from memory at the proper time and direct it to the proper feeders and actuators. These signals represent the rotational position of the knitting machine with respect to a reference position in terms of needle distances, and a plurality of multiple needle distances including an echelon, a byte, and a feeder distance. Knitting machine revolutions are also represented, and the number of revolutions uniquely represented between appearances of reference position is selectable to accommodate a plurality of pattern types and heights.

Therefore, it is an object of the present invention to provide an improved optical shaft encoder for use with circular knitting machines.

It is a further object of the present invention to provide an encoder to generate signals representative of knitting machine position in terms of needle distances and multiple needle distances.

It is a still further object of the present invention to provide an encoder to generate signals representative of knitting machine revolutions, and to provide means for selecting the number of revolutions uniquely represented between appearances of the reference position.

These and other objects and advantages of the present invention will become apparent as the detailed description proceeds, reference being made to the attached drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified elevation view of a circular knitting machine, partially cutaway to reveal the knitted hose and take-down mechanism.

FIG. 2 is a generalized block diagram showing how the encoder of the present invention fits into the control system.

FIG. is an illustration ofa code disc having a plurality of concentric code tracks comprising transparent and opaque code zones.

FIG. 4 is a developed view of a portion of the fine code disc showing its origin.

FIG. 5 is a logic circuit diagram illustrating how signals from the photocells reading the fine disc are operated upon logically to produce the desired binary code.

FIG. 6 is a developed view of a portion of the coarse code disc showing its origin.

FIG. 7 is a logic circuit diagram illustrating how the signals from the photocells reading the coarse code disc and some of the signals from photocells reading the coarse code disc are operated upon logically to produce the desired binary code.

DESCRIPTION OF THE PREFERRED EMBODIMENT The general relationships between the positional signals required by the control described in application Ser. No. 19,047 filed Oct. 27, 1971 by Paul Christiansen and entitled Knitting Machine Controls and the relationships with other circular knitting machines are somewhat similar, but will differ in detail according to the specific geometry of each knitting machine and other factors. For example, the knitting machine controls of the Christiansen application require an indication of actuator or needle count, feeder count and revolution count as knitting progresses. However, one knitting machine may have 48 feeders and 2,400 needles, while another may have 36 feeders and 1,728 needles. One may knit 12 repeats of a pattern while the other knits nine repeats of the same size pattern. Because of these differences, no standard binary arithmetic or Gray code encoder can readily be used to generate the required signals. Nor, may an encoder made according to the present invention for one knitting machine generally be usable with another knitting machine having a different number of needles and feeders. Another encoder, however, embodying the subject matter of the present invention could be constructed to accommodate the specific geometry of the other knittingmachine.

To illustrate the encoder of the present invention, one specific embodiment will be shown and described for use with a circular knitting machine having 1,872 needles and 36 feeders. As the knitting machine cylinder turns, each of the needles is sequentially brought into operative relationship with each of the feeders. At each feeder, each needle must knit or non-knit. That is, it must move up to the knit position and take a new loop or stay below the knit position and not create a new loop. The term knit as used herein will include tuck wherein a new loop is created without throwing off the old loop.

At each feeder there are cam tracks that cooperate with projecting cam butts on needle jacks and selector jacks to lift the needles to the required height. Needles are selected to knit or non-knit by electromagnetic actuators that either interfere with a selector butt on a selector jack, causing its cam butt to enter the non-knit cam track, or do not interfere with the selector butt so that the cam butt enters the knit cam track. Thus, because there are 1,872 needles and 36 feeders in the illustrative knitting machine, 36 X 1872 or 67,392 knit and non-knit commands must be supplied to the actuators each revolution of the knitting machine. If the illustrative knitting machine were operated at 24 revolutions per minute, then the actuators would require about 27,000 knit and non-knit commands per second. Although this is not a high data transmission rate for electronic digital computers, it is quite a high data transmission rate to interface to a mechanical apparatus such as a knitting machine. The encoder of the present invention permits handling the necessary knit and non-knit information at the required data transmission rates with considerably fewer electronic manipulations, and therefore greater economy, than could otherwise be achieved.

As described in more detail in application Ser. No. 193,047 referred to above, pattern data is stored on nine tracks of a magnetic disc. Each track is divided into four zones. One zone stores all the pattern data for one feeder for a complete pattern. An arbitrary pattern size of 208 stitches wide by 216 stitch rows high was selected for use on the illustrative knitting machine. Thus, because there are 1,872 needles around the cylinder, the pattern will be knitted nine times around the circumference of the finished knitted tube. The number of revolutions required to knit the 216 stitch rows of pattern height, however, will depend upon the type of pattern being knitted. For example, three-color plain pattern requires three feeders per stitch row. Therefore, the illustrative machine will knit l2 stitch rows per revolution and require 18 revolutions to knit 216 stitch rows. For a pattern requiring only two feeders per stitch row, the illustrative machine will knit 18 stitch rows per revolution and would require only 12 revolutions to knit 216 stitch rows.

In both the examples given above, the pattern would be knitted nine times during the required number of revolutions. This is true for all patterns 208 stitches wide knitted on the illustrative machine. Or, stated in another way, the stored pattern data will be used nine times during the required number of revolutions to knit 216 stitch rows.

The four zones of each data track on the magnetic disc are divided into sectors such that a sector contains all the knitting data required for one feeder for one full stitch row of the pattern. Since a pattern width of 208 stitches has been selected, each sector must contain 208 bits of data. Because a feeder knits on the same stitch row of the pattern for one full revolution of the knitting machine, which is nine repeats of the pattern in the present embodiment, a new sector address is required only once per revolution. The information from the sector, however, will be used nine times during the revolution. Revolution count and sector address are provided by the encoder and its associated translator circuitry.

Because of operating speed limitations of the electromechanical actuators, the task of steering the needles at each feeder is divided among 13 actuators. In this manner, each actuator steers only every 13th needle. Thus, signals are required for directing the knit and non-knit information to the proper actuator at each feeder. These signals are also provided by the present encoder and its associated translator circuitry.

Because a continuous flow of knit and non-knit information is required by each feeder and because information is retrieved from the disc in a discontinuous manner, an interface is required between the disc and each feeder. This interface, in the present embodiment, may include two 26 bit shift registers per feeder. While the information is being read out of one of the shift registers, information is located on the disc and loaded into the other shift register. Therefore, by switching back and forth between its two associated shift registers. a feeder receives a continuous flow of patterning information. In an alternative system, a single 208 bit shift register is provided for each feeder and a 208 bit buffer shift register provides the time interface between the disc and all the feeder shift registers. In the first system the 26 bits required to load each shift register are taken from the 26-bit bytes of information on the disc. In order to retrieve these bytes, a byte address is required in addition to the sector address. The byte addresses are provided by the present encoder and its associated translator circuitry. In the second system, byte addresses are not required. Instead, the 208 bits in each feeder shift register are recirculated for a full knitting machine revolution.

Two-color plain patterns, and one-color tuck patterns, require two feeders per stitch row. Three-color plain patterns, and oneand two-color blister patterns require three feeders per stitch row. Four-color plain patterns and three-color blister patterns require four feeders per stitch row. An arbitrary pattern height of 216 stitch rows then requires twelve revolutions, 18 revolutions, and 24 revolutions for two, three, and four feeder-per-stitch row patterns, respectively. In order to selectively knit two, three, or four feeder-per-stitch row patterns, the encoder signals must recycle to the beginning after 12, 18 or 24 machine revolutions. To knit a two-feeder-per-stitch row pattern 108 stitch rows high, the encoder signals must recycle after six revolutions. Other combinations may also be desired. To avoid prolixity of description, the controls of the above identified Christenson application Ser. No. 193,047 will not be set forth in detail herein. However, it should be understood that the disclosure of this application is fully incorporated herein by this and other references thereto.

FIG. 1 is a diagrammatic illustration of a circular knitting machine 10 partially cut away to show the finished knitted tube 11 and the take-down mechanism 12. A creel structure 13 supports spools of yarn 14 to be knitted. The yarn passes through tensioning means 15 and stop motions l6 and 17 to feeder blocks located circumferentially around the knitting machine at 18. A large ring gear 21 mounted to the lower portion of the knitting machine or needle cylinder drives a pinion gear 22 mounted on the input shaft of optical shaft encoder 25 which is affixed to the frame of knitting machine 10 in any suitable manner. As the knitting machine cylinder rotates, ring gear 21 drives pinion gear 22 to rotate the input shaft of encoder 25.

Within encoder 25 are two code discs, a fine code disc 27 (FIGS. 3 and 4) and a coarse code disc 28 (FIG. 6). Fine code disc 27 is mounted for rotation on a shaft that is gear coupled to input shaft 26 such that fine code disc .27 rotates three full revolutions for each rotation of the knitting machine needle cylinder. Coarse code disc 28 is mounted for rotation on a shaft that is gear coupled to the fine code disc shaft such that coarse code disc 28 rotates one full revolution for each 216 fine code disc revolution, which is one full revolution for each 72 knitting machine cylinder revolutions.

Each of the

encoder discs

27, 28 have a plurality of code tracks with which a plurality of photocells cooperate to provide a plurality of binary coded electrical signals. These signals may be used directly, or be operated upon logically to provide further binary coded signals, to provide the necessary synchronizing and position indicating information for the knitting machine control. It is not necessary to describe in detail here the relationship between encoder discs, light sources, and photocells, because these details are well known in the art. For example, see US. Pat. No. 3,218,626 issued Nov. 16, 1965 to Ralph H. Schuman and assigned to the assignee of the present invention.

FIG. 2 is included to illustrate generally where and how encoder 25 fits into and cooperates with the overall knitting machine and control. The circular knitting machine, including its drive, feeders, cylinders, etc., is represented by the block 31. The mechanical coupling between the knitting machine cylinder and encoder 25, including

gears

21 and 22, is represented by block 32. Many of the binary electrical signals generated by encoder 25 are operated upon logically by translator circuitry 33 to provide derived signals. Both the derived signals and signals from encoder 25 are used by a plurality of feeder controls 34 to retrieve the proper knitting data from memory means, such as a magnetic disc, and provide the proper knit and non-knit signals to the feeder actuators in block 31. It will be recognized that the immediately foregoing description of how the encoder of the present invention fits into the overall control is very abbreviated. The overall control is fully described in Paul Christiansens Application Ser. No. 193,047 filed Oct. 24, 1971, entitled Knitting Machine Controls and referred to above.

FIGS. 3 and 4 show the arrangement of the code tracks and photocells of the first or fine disc 27. The presence of crosshatching indicates an area of a transparent characteristic that will permit light to pass and illuminate a photocell to generate a logic one signal. The absence of crosshatching represents an area of an opaque characteristic that will prevent light from illuminating a photocell to thereby generate a logic zero. Because the fine disc 27 makes one revolution for each one-third revolution of the knitting machine, it must resolve 1,872 3 or 624 parts per revolution to provide a change in signal each time the needles are advanced one needle position during a revolution of the needle cylinder. This is achieved by dividing the finest code track 40 into 312 opaque and 312 transparent zones of equal size and alternately located around the code track with each of the opaque and transparent zones corresponding to a needle position. The code track 40 is utilized to provide needle signals which vary in response to relative movement between the needle cylinder and feeders by an extent corresponding to the spacing of adjacent needles.

A pair of

photocells

41, 42 are connected in a pushpull relationship and positioned 180 of a needle position out of phase with respect to fine code track 40 to read the fine code track through mask slits 43 which have a width that is approximately one-third the tangential dimension of either an opaque or transparent code zone. This provides a signal which, after amplification, is considerably more precise than onetenth of a code zone, or, related to the knitting machine, onetenth of a needle distance. The fine code track photocell outputs are labeled A+ and A. These outputs are fed in push-pull to an amplifier 44 (FIG. 5) to produce a signal A which is at logic one when photocell 41 is illuminated. Amplifier 44 also produces a signal A, the complement of signal A. Signals A and A are connected respectively to monostable multivibrators 47 and 48. Monostable multivibrator 47 produces a short pulse output each time signal A changes from logic one to logic zero and monostable multivibrator 48 produces a short pulse output each time signal A changes from logic one to logic zero. The outputs of monostable multivibrator 47 and 48 are combined by or gate 49 to produce on line 50 one pulse each time the knitting machine has moved one needle position. These pulses may be used to transfer patterning data from feeder control storage to the actuators. An additional monostable multivibrator 51 which generates a short pulse output each time the signal on line 50 changes from one to zero may be used to shift feeder control shift registers in timed relationship with rotation of the needle cylinder in a manner more fully described in the aforementioned Christiansen application Ser. No. I93,047. In order to provide an enabling signal to each of the thirteen actuators at each feeder, it is necessary to provide an actuator or needle count number to indicate which of the thirteen needles in each echelon is to be steered next. To produce this indication, a second code track 55 is provided on the fine disc 27. This code track 55 is divided into 24 transparent and 24 opaque code zones, each having a tangential length substantially equal to 13 finest code track 40 code zones (48 X 13 624). Thirteen photocells 56 are arranged to read the second code track in a staggered or phase displaced manner to provide 13 outputs that are labeled B, C, D, E, F, G, H, I, J, K, L, M, and N in FIGS. 4 and 5.

The signals from the thirteen photocells 56 are combined logically according to the Boolean Algebra equa-.

tions of Table I to provide the actuator enabling signals E0 E12 corresponding to the number of an actuator to be enabled for activation in accordance with a pattern signal from a suitable memory device (not shown but fully described in the aforementioned Christiansen application). Since each opaque and transparent zone of the code track 55 corresponds to 13 needles and associated actuators, any one of which may require activation to knit a selected pattern, thirteen enabling signals E0 E12 are provided for each of the opaque and transparent zones of the code track 55. The actual decoding circuitry is illustrated in FIG. 5 wherein each of the photocells 56 is connected to an inverter 57 to produce the signals B, C, I E, F, G, FLT, T, KI, K1 and N as well as B, C, D, E, F, G, H, I, J, K, L, M, and N.

To produce each of the enabling signals E0 E12 for each transparent and opaque zone of the code track 55, the photocells 56 are paired by the logic circuitry of FIG. 5. When the leading photocell of a pair is adjacent an opaque zone and the trailing cell is adjacent a transparent zone an enabling signal is produced. In addition, when the leading photocell of a pair is adjacent a transparent zone and the trailing cell is adjacent an opaque zone another enabling signal is produced. Thus, for the pair of cells B and M, an enable signal E is produced by combining KB, and M in an and gate 58, combining A, B, and M in an and gate 59, and combining the outputs of and gates 58 and 59 in or gate 60. This produced E0 in accc dance with the Bo olean equation E0 AB M A B M. Similarly A, C, N, A, C, and N are combined in and gates 61 and 62 and or gate 63 to produce E1 according to the Boolean equation E1 A C N KC N. Each of the remaining enable signals E2 E12 are produced similarly in accordance with the Boolean equations of Table l, the circuitry for producing E2 Ell being omitted to avoid unnecessary prolixity.

E11=AKM+AKM E12 A L N A t N Because in the aforementioned Christiansen application there are 26 bits in a byte in the selected pattern data format, it is necessary to provide 26 discrete steering signals to transfer each pattern data bit from a 26 bit shift register to one of thirteen actuators. One manner of accomplishing this is to provide an additional signal that is at logic one during alternate echelons of needles. For this reason, a third code track 64 is provided on fine disc 27 having alternate transparent and opaque areas each having a tangential length substantially equal to 26 finest code track 40 code zones. Photocells 65 are positioned 90, or 6 1/2 fine code track zones out of phase to read code track 64 to provide outputs that ge labeled 0 and P. Inverters 66 produce the signals O and 1 Should it be desired to keep track of echelons of needles, e.g. whether the echelon is even or odd, such a signal may be provided by associating even echelons with opaque zones of the code track 55 and odd echelons with transparent zones of the code track 55. This may be accomplished by logically combining signals A, B, L, M, and N according to the Boolean equation, EEl A B M L N A I: N with and gates 67, 68, 69, and or gate 70. This produces a logic one when the echelon is odd and a logic zero when the echelon is even. Similarly, a byte signal may be produced by the logical combinationEBI=ABM+NO+MP+ALNwithand gates 71 74 and or gate 75. Signal EBl will be at logic zero when the byte number is even and at logic one when the byte number is odd, and may be used to steer bytes read from the disc to the proper one of two feeder shift registers. The byte signal is also used in determining the feeder number as will be described below.

During operation of the knitting machine 10, pattern data for at least a portion of a particular stitch row is transmitted from a memory disc to controls for a feeder of a feeder group which is knitting this particular stitch row. The pattern data for any one feeder of a feeder group may be different than the pattern data for any other feeder in the feeder group. Since different stitch rows of a pattern are knitted by each feeder group on consecutive revolutions of the needle cylinder, the pattern data for any one feeder may be different on different revolutions of the needle cylinder. In addition, dur' ing any one revolution of the needle cylinder from feeder 0 to feeder 35, the feeder groups ahead of a first needle on the cylinder and the pattern change point will be completing the knitting of a stitch row corresponding to the preceeding revolution of the needle cylinder while the feeder groups behind the first needle and after the pattern change point will be knitting a stitch row corresponding to the present revolution of the needle cylinder. It should be understood that the beginning and ending points of a stitch row are displaced longitudinally along a generally cylinderical tube of knitted material by a number of stitch rows corresponding to the number of feeder groups. Therefore, the pattern change point extends linearly along the tube of knitted material.

A feeder count number which is indicative of the feeder in which the first needle on the needle cylinder and pattern change point are located is transmitted from the translator 33 to the feeder controls 34. To provide a feeder number which changes with movement of the pattern change point and of the first needle on the needle cylinder from feeder 0 through feeder 35 with each revolution of the needle cylinder, the fine code disc has three additional code tracks 81, 82, and 83. Note the change of scale in FIG. 4 between code tracks 64 and 81. Code track 81 is equally divided into six opaque and six transparent code zones. Because the fine code disc rotates one revolution for each one-third revolution of the knitting machine, and since there are 36 feeders and 52 needles per feeder on the knitting machine, one code zone on code track 81 corresponds to one feeder on the knitting machine and 52 zones of code track 40. Code track 82 is divided into two transparent and two opaque code zones, the opaque zones being twice as long as the transparent zones and alternately located with the transparent zones as shown in FIG. 4. Thus, an opaque zone of code track 82 corresponds to four feeders and a transparent zone corresponds to two feeders. Code track 83 is divided into two equal code zones, one transparent and one opaque. Each of the zones of code track 83 corresponds to six feeders. Lead and lag photocells 84 are positioned as shown in FIG. 4 and cooperate with

code tracks

81, 82, and 83 to provide binary code signals FlD, FIG, F2D, F2G, F4D, F4G, F6D, and F6G.

The lead photocell (D) of each photocell pair is located so that it reads ahead of the actual transition point and each lag photocell (G) is located so that it reads behind the actual transition point. The byte signal (EBl) is utilized to switch between lead and lag photocells 84. Lead-lag switching is accomplished by and gates 84D, 84G, 85D, 85G, 86D, 866, and 87D, 876, and or gates 88, 89, 90, and 91, connected as shown in FIG. 5. Signal EBl is directly connected to one input of each and gate 84G, 85G, 86G, and 87G, to enable those gates when EBl is at the logic one level during odd bytes. Signal EBl is connected to one input of each and gate 84D, 85D, 86D, and 87D, through an inverter 92 to enable those gates when B81 is at the logic zero level during even bytes. Because the byte signal depends on the A signal for its accuracy, and because the A signal is accurate to approximately one-tenth needle position, use of the byte signal to control the lead-lag switching on photocells 84 provides binary code signals EF1, EF2, EF4, and EF6, weighted 1, 2, 4, and 6, and

indicating feeder numbers from thru 11 with an accuracy of one-tenth needle position. I

In order to provide feeder numbers 0 35 on each needle cylinder revolution, feeder numbers 0 11 are generated three times. That is, during a first revolution of the fine code disc 27, code tracks 81, 82, and 83 are decoded to indicate feeders 0 11. The next revolution they are decoded to indicate feeders l2 23. During the third revolution they are decoded to indicate feeders 24 35. The coarse code disc 28 is associated with the fine code disc 27 to provide the necessary information as to which series of feeder numbers is being provided at any given time. Thus, the code tracks 81, 82 and 83 are utilized to provide coded feeder signals which vary in response to relative movement between the needle cylinder and feeders by an extent which is a function of the spacing of adjacent feeders. These coded signals are indicative of the feeder with which the first needle is associated.

Whether code tracks 81, 82, and 83 should be decoded as feeders 0 11, 12 23, or 24 35, is determined by signals generated by code tracks on the coarse code disc 28 that is coupled to the fine code disc 27 by gear means giving a 216:1 gear ratio such that coarse code disc 28 rotates one time for each 216 revolutions of the fine code disc. This means that the coarse code disc will rotate once for each 72 revolutions of the knitting machine. The coarse code disc 28 has seven code tracks concentrically arranged similarly to the code tracks of fine code disc 27 shown in FIG. 3. These are identified in order of decreasing diameter by reference numerals 93 99 and are illustrated in a developed view in FIG. 6. Code track 83 of fine disc 27 is shown at the top of FIG. 6 to illustrate the relationship between

code discs

27 and 28. As was previously mentioned, each of the zones of code track 83 corresponds to six feeders. The numerals immediately below code track 83 in FIG. 6 indicate revolutions of the needle cylinder, each of which corresponds to three revolutions of the fine disc 27. Note the scale change between code tracks 96 and 97.

Signals indicative of which of the three revolutions is being made by the fine code disc 27 are provided by four photocells 101 arranged in two lead-lag pairs to read code track 93 and provide signals F12D, F12G, F24D, and F24G. As shown in FIG. 7, leadlag switching is accomplished by and gates 103 and or gates 104. And gates 103 are alternately enabled to select either the lead or lag signals by means of signal EF6 being directly connected with the lag gates and connected to the lead gates through an inverter 105. Thus, when transparent zones (crosshatched) on code track 93 are being read and signal EF6 is at the logic one level, signals F126 and F240 are enabled. When opaque zones (not cross-hatched) on code track 93 are being read and signal EF6 is at the logic zero level and signals F12D and F24D are enabled.

When code tracks 81, 82 and 83 are to be decoded as feeders 0 11 the gated photocells 101 are reading opaque zones of code track 93 and the enabled signals EF12 and EF24 are at logic level zero. During continued rotation of the needle cylinder certain of the photocells 101 read transparent zones of code track 93 and the code tracks 81, 82 and 83 are decoded as feeders 12 23. During this time signal EF12 is at logic level one while EF24 remains at logic level zero. Upon still further rotation of the needle cylinder, code tracks 81, 82 and 83 are decoded as feeders 24 35 and signal EF12 returns to logic level zero while signal EF24 is at logic level one. Thus both signals EF12 and EF24 remain at logic level zero for 24 consecutive feeder numbers and are at logic level one for 12 consecutive feeder numbers.

To enable signal EF12 to remain at logic level zero for feeder numbers 24 35 during one revolution of the needle cylinder and for the immediately succeeding feeder numbers 0 11 on the next revolution of the needle cylinder, code track 93 has 72 opaque zones which are read by photocells F12D and F12G during feeder numbers 24 35 of one needle cylinder revolution and feeder numbers 0 11 of the next needle cylinder revolution. However, signal EF12 is at logic one level during feeder numbers 12 23 of each needle cylinder revolution. Accordingly, code track 93 has 72 transparent zones (shown crosshatched in FIG. 6) which are read by the photocells F12D and F12G during feeder numbers 12 23. The transparent zones of code track 93 are one half as long as the opaque zones.

The signal EF24 remains at logic level zero during feeder numbers 0 23 and is at logic level one during feeder numbers 24 35. Thus, signal EF24 switches to logic level one as signal EF12 switches from logic level one to logic level zero. Accordingly, photocells F24D and F246 read a transparent zone of code track 93 immediately after it is read by the photocells F12D and F12G.

The signals produced by photocells 101 may be considered as adder signals for combining with the EF1, EF2, EF4, and EF6 signals to produce a binary code weighted 1, 2, 4, 6, 12, 24. The truth table for the feeder numbers is as follows:

COARSE DISC FINE DISC Feeder No. EF24 EFl2 EF6 EF4 EF2 EH 0 O 0 O 0 V 0 O l 0 O 0 0 0 l 2 0 0 0 O l 0 3 O 0 0 0 l l 4 O 0 0 l O 0 5 0 O O l 0 l 6 O 0 l 0 O 0 7 0 0 l 0 0 l 8 0 0 l 0 l 0 9 0 0 l O l 1 l0 0 0 l l O 0 l l 0 O l l 0 1 l2 0 l O 0 0 0 l3 0 l O 0 0 l 14 0 l O O l 0 l5 0 l 0 0 l 1 l6 0 1 O l 0 0 l7 0 l 0 l O 1 l8 0 l l 0 0 0 l9 0 l l O O l 20 0 l l 0 l O 21 O l l O l l 22 0 l l l 0 0 23 O l l l O .l 24 I 0 0 O 0 0 25 l 0 0 0 0 l 26 l O O 0 l O 27 l 0 0 0 l l 28 l 0 O l 0 0 29 l 0 O I O l 30 l 0 l 0 0 0 31 l 0 l O 0 l 32 l 0 l 0 I O 33 l 0 l 0 l l -Continued COARSE DISC FINE DISC Feeder No. EF24 EFl2 EF6 EF4 EFZ EFI 34 l l l 0 0 35 l 0 1 l 0 1 By proper digital arithmetic techniques, these signals may be translated to feeder count numbers in any desired code, e. g. normal binary weighted 1, 2, 4, 8, 16, etc. FIG. 7 shows how signals EFl EF24 may be translated to normal binary by the use of a S-stage full binary adder or register means 111 having carry-in and carry-out capacity. Adder 111 is arranged to add two normal binary numbers, A and B, plus a carry-in bit at C-in, and produce their sum 5. The electrical signals representing number A are connected to terminals Al A16 and those representing number B to terminals B1 B16, the terminal reference numerals also indicating the numerical weight of their digit signals. The signals representing the sum appear at terminals S1 S16 and at carry-out terminal C-out. EFl, EF2, and EF4 are directly connected to A1, A2, and A4, respectively. EF6, weighted 6, is connected to Gin and B1 via an and gate 112, and thence to B4 via one input of or gate 113.

When and gate 112 is enabled, a logic one on EF6 will cause logic ones to appear at C-in, B1, and B4 contributing six toward the sum S. EF12, weighted 12, is connected to B8 via an and gate 115, and thence to B4 via the other input of or gate 113. Thus, when and gate 115 is enabled, a logic one on EF12 will cause logic ones to appear at B4 and B8, contributing twelve toward the sum S. EF6 and EF12 are also connected to an and gate 116, the output of which is connected to B2 and B16. Thus, when EF6 and EF12 are both at logic one, logic ones appear at B2 and B16, contributing 18 toward the sum S. The output of and gate 116 is also inverted by an inverter 117, the output of which provides the enabling signal for and gates 112 and 115. Thus, when EF6 and EF12 are both at logic one, and gates 112 and 115 prevent logic ones from appearing at C-in, B1, B4, and B8. EF24, weighted 24, is directly connected to A8 and A16, and therefore, a logic one on EF24 contributes 24 to the sum S. The sum appearing at terminals S1 S16 and Com indicates the knitting machine feeder count number in normal binary arithmetic. The feeder count number digit signals are designated F1, F2, F4, F8, F16, and F32, the numerical portion of the designation indicating the numerical weighting of the digit signal.

The feeder count number is transmitted from the translator 33 to the feeder controls 34 and is utilized to provide a feeder offset number which shifts from logic level zero to logic level one immediately before the pattern change point enters a feeder. The operation of the feeder controls 34 is not, per se, a part of the present invention and therefore has not been fully described. However, the operation of the feeder controls is fully set forth in the aforementioned Christiansen application.

It is contemplated that the knitting machine will be utilized to knit many different types of patterns, such as two, three or four color plain patterns or one, two or three color blister patterns. In order to enable the machine 10 to knit these different patterns, the 36 feeders'are associated in a known manner in groups of either two, three or four feeders, depending upon the pattern to be knitted. Assuming a constant pattern of 216 stitch rows, the number of revolutions required to knit a pattern will vary depending upon the number of feeders in each feeder group. Thus, for a pattern having one feeder in each feeder group, six revolutions of the needle cylinder are required to knit the pattern. For a pattern having two feeders in each of eighteen feeder groups, 12 revolutions of the needle cylinder are required to knit the pattern. Similarly, a three feeder group pattern is knitted in 18 cylinder revolutions and a four feeder group pattern is knitted in 24 cylinder revolutions.

Once a pattern has been knitted during the requisite number of needle cylinder revolutions, the pattern is repeated as the needle cylinder continues to rotate. To facilitate for this repetitive knitting of the pattern, the signals from the encoder 25 are repeated each time the needle cylinder rotates through the requisite number of revolutions. Thus, the signals from the encoder 25 are repeated after every six revolutions when one feeder is used in each feeder group to knit a 216 stitch row pattern. Similarly, the signals from the encoder 25 are repeated after twelve revolutions for a pattern requiring two feeders per group, after 18 revolutions for a pattern requiring three feeders per group, and after 24 revolutions for a pattern requiring four feeders per group.

To enable the signals from the encoder to be repeated in the number of revolutions corresponding to the selected pattern,

photocells

120, 121, 122, 123, 124, and 125 cooperate with

code tracks

94, 95, 96, 97, 98, and 99 to provide revolution count signals which repeat after either six, l2, 18 or 24 cylinder revolutions. A selector switch 133 (FIG. 7) is provided to enable the cycling of the revolution count to be matched with a selected pattern.

To provide repetitive revolution count signals, code track 94 is equally divided into 36 transparent and 36 opaque code zones of equal tangential length alternately located about the code track. Lead and lag photocells reading this code track are switched by the EF6 signal in the same manner as the signals from photocells 101 to produce one change of a signal ER1 for each revolution of the knitting machine. Thus, the ER1 signal functions as the units digit signal for a binary coded set of signals indicating revolution number. The additional binary coded digit signals for indicating revolution number are generated by code tracks 95 99 and photocells 121 125 as shown in FIGS. 6 and 7. Each of the photocells 121 125 are arranged in leadlag pairs to produce signals R2D, R2G, R4D, R6D, R66, R6/3D, R6/3G, Rl2/3D, R12/3G, R12D, R120, R24D, R246. These signals are connected to and gates 128 that are switched by the ER1 signal in the same manner that the EF6 signal switches the signals from

photocells

101 and 120. Or gates 129 combine the signals from and gate pairs. Since the ER1 signal is switched by the EF6 signal, which in turn is switched by the A signal, one-tenth needle position accuracy is maintained in resulting revolution number signals ER1, ER2, ER6, ERG/3, ERl2/3, and ER12. The truth table for these signals is as follows:

Switched by ER6 ER24 ERl2 Needle Lead- Cylinder Lag Rev. ER48 Lead Lag ER6/3 ERG Switched by ER! ER4 ER2 ERl CCCOOOO U (I 1) I) ll! 0 O l l l) 0 l2 0 0 I] 0 0 To provide a revolution count which is cyclic in six revolutions to knit a 216 stitch row pattern requiring only one feeder per group, the selector switch 133 (FIG. 7) is set to position X6. When the selector switch is in this position, only signals ER], ERZ and ER4 are utilized to repetitively count from zero to five. Thus, on the sixth, 12th, 18th, etc., needle cylinder revolutions the signals ERl, ER2 and ER4 are logically combined to indicate revolution zero when the selector switch 133 is set to position X6.

A revolution count which is cyclic in 12 revolutions is necessary to knit a 216 stitch row pattern requiring two feeders per group. To accomplish this the selector switch 133 is set to position X12 and signals ERl, ER2,

ER4 and ER6 are utilized to repetitively count from zero to eleven.

When the selected pattern requires three feeders per group, the selector switch 133 is set to position 18X to enable signals ERl, ER2, ER4, ER6/3 and ER12/3 to be combined to provide a revolution count which is cyclic in eighteen revolutions. It should be noted that the ER6/3 signal was utilized rather than the ER6 signal. This is because repetitive counting to eighteen requires that the signal given a weight of six must be at logic level zero for cylinder revolutions l2 17 during one counting cycle and remain at level zero for revolutions 5 of the next following counting cycle. Since the ER6 signal must change logic levels every six revolutions to enable this signal to be used for a revolution count which is cyclic in 12 revolutions, this signal is unsatisfactory for use in providing a revolution count. which is cyclic in 18 revolutions. It should likewise be noted that the ER12/3 signal was utilized rather than the ER12 signal. This is because repetitive counting to 18 requires that a signal given the weight of 12 must be at a logic one for cylinder revolutions 12-17 during each counting cycle, and the ER12 signal is at a logic zero during a needed portion of the entire 0-71 cylinder revolution counting capacity of the coarse disc, i.e., the ER12 signal is at a logic level zero during needle cylinder revolutions -35 and 48-53 as can be seen frqm. t s mitlttablsz Finally, when a 216 stitch row pattern requiring four feeders per group is to be knitted, the selector switch is set to position X24. This setting of the selector switch results in signals ERl, ER2, ER4, ER6 and ER12 being utilized to provide a revolution count which is cyclic in 24 revolutions.

Referring to FIG. 7, it will be seen that signals ERl, ER2, and ER4 are connected to the Al, A2, and A4 terminals of a full binary adder or register means 131 which is identical to and has terminals identified the same as adder 111. A multi-position selector switch 133 has a wiper contact 132 connected to a source of voltage +V which represents a logic one. Each of the terminals of switch 133 may be connected to ground (logic zero) by a resistor 134 to insure that a logic zero appears thereon whenever the wiper contact 132 is turned to another position. The terminals are designated X6, X12, X18 and X24, the numerical portion of the designation indicating the number of revolutions per pattern cycle.

The logic circuitry for gating revolution number signals ERl ER24 is fully described by the circuit diagram of FIG. 7 and therefore need not be described verbally. Turning switch 133 to its various positions operates to enable different combinations of and gates to pair selected ones of signals ER6, ER6/3. ER12/3, and

ER12 to adder 131. Selective translator circuitry for utilizing ER24 and ER48 is not shown in FIG. 7, however, the translator circuitry illustrated may be readily extended to encompass those signals. For example, ER24 would, via appropriate gating, enabled by an additional terminal on switch 133, be selectively connected to A8 and A16 of adder 131, thereby contributing 24 toward the sum at the proper time. Thus, the code tracks 93-99 cooperate with the associated readers to provide coded revolution signals which vary in response to relative movement between the needle cylinder and feeders by an extent which is a function of one complete revolution of relative movement. These coded revolution signals are indicative of the number of revolutions of relative movement which have occurred.

By way of illustration, two translator configurations will be described in detail. First, with switch 133 in the X6 position, only and

gates

141 and 142 will be enabled by the output of inverter being at logic one because the output ofand gate 139 is at logic zero. The output of and gate 139 can be at logic one only when switch 133 is in the X24 position. However, because and

gates

143, 144, 145, and 146 are disabled, no signals other than ERl, ER2, and ER4 will reach adder 131. Therfore, the output of adder 131 will be normal binary that counts 0 5 and repeats. These revolution signals are associated with the feeder controls 34 in the manner fully described in the aforementioned Christiansen application to repeat a selected pattern after every six revolutions of the needle cylinder.

With switch 133 in the X18 position, as shown in FIG. 7, and

gates

144 and 145 are enabled to pass the ER6/3 and ER12/3 signals to adder 131. Disabled and

gates

143 and 146 prevent the passage of signals ER6 and ER12. Signal ER6/3 is connected via and gate 144 and or gate 147 to B2, and thence via or gate 148 to 134. Thus, when ER6/3 is at logic one, B2 and B4 are at logic one, contributing six to the adder output. Similarly, signal ER12/3 is connected via and gate 145 and or gate 149 to B8, and thence via or gate 148 to B4. Thus, when signal ER12/3 is at logic one, twelve will be contributed to adder 131 output. Because ER6/3 and ER12/3 are never both at logic one at the same time, both signals may share the B4 terminal of adder 131.

The output of adder 131 is the revolution number in normal binary arithmetic. The revolution number digit signals are designated R1, R2, R4, R8, R16, and R32, the numerical portion of the designation indicating the numerical weighting of the digit signal.

Description of how the signals generated by the encoder of the present invention are utilized by the knitting machine control in the manner fully described in Paul Christiansen application Ser. No. 193,047 filed Oct. 27, 1971, and entitled Knitting Machine Controls. Suffice it to be said here that the encoder of the present invention provides electrical signals necessary for generating data addresses for retrieving patterning information from a memory, and provides signals for insuring that the right data reaches the right actuator at the right time. Those who are interested in the manner in which the signals from the encoder 25 may be utilized to effect operation of a knitting machine are referred to the aforementioned Christiansen application.

It will be appreciated that the arithmetic base of the encoder of the present invention may be altered to suit the requirements of any particular circular knitting machine without departure from the spirit or scope of the claims. It should also be understood that although the present invention has been described herein in association with a knitting machine of the type in which the needle cylinder rotates relative to stationary feeders, the present invention could be utilized in association with a known type of knitting machine in which the feeders rotate relative to a stationary needle cylinder. It should also be understood that although it is contemplated that the present invention can advantageously be used with the knitting machine controls of the aforementioned Christiansen application, the present invention can also be used in conjunction with other knitting machine control systems.

Having described a specific preferred embodiment of the invention, the following is claimed:

1. Apparatus for use in a knitting machine having a needle cylinder holding a plurality of needles to which strands of material are fed from feeders during relative rotation between the needle cylinder and feeders to knit a predetermined one of a plurality of different patterns the knitting of each of which requires different numbers of revolutions of relative rotation between the needle cylinder and feeders with the feeders associated with each other in groups of any one of a plurality of different sizes, wherein said apparatus comprises encoder means for providing signals which vary with variations in the relative position of the needle cylinder and feeders and for providing revolution signals which vary with revolutions of relative rotation between the needle cylinder and the feeders, said encoder means includes a first code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of said first code track being of the same longitudinal extent, a second code track having a plurality of zones of the first characteristic and a plurality of zones of a second characteristic, each of said zones of a first characteristic of said second code track being of the same longitudinal extent as one of said zones of a first characteristic of said first code track and each of said zones of a second characteristic of said second code track being of a longitudinal extent which is at least twice as great as the longitudinal extent of one of said zones of a second characteristic of said first code track, first reader means for cooperating with each of said zones of the first characteristic of said first code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for a first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said first code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions, and second reader means for cooperating with each of said zones of a first characteristic of said second code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said second code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for a second predetermined number of revolutions which is at least twice as great as said first predetermined number of revolutions, control means for receiving signals from said encoder means and for effecting activation of the needles during relative rotation between the needle cylinder and feeders, said control means including revolution register means activated in response to revolution signals from said encoder means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders and for sequentially repeating said series of coded revolution count signals each time a predetermined number of revolutions of relative rotation occurs between the needle cylinder and feeders during operation of the knitting machine,

means for effecting a knitting of a selected one of the plurality of patterns each time said series of coded revolution count signals is repeated by said revolution register means, and selector means for varying the predetermined number of revolutions required to effect a repetition of said series of coded revolution count signals by said revolution register means to enable the knitting machine to knit patterns requiring different numbers of revolutions of relative rotation between the needle cylinder and feeders, said selector means including switching means for effecting a transmittal of signals from said first reader means to said revolution register means during the knitting of a pattern requiring a first predetermined number of revolutions of relative movement between the needle cylinder and feeders and for effecting transmittal of signals from said second reader means to said revolution register means during the knitting of a pattern requiring a second predetermined number of revolutions of relative movement between the needle cylinder and feeders.

2. Apparatus as set forth in claim 1 wherein said encoder means further includes means for providing feeder signals which vary as a function of relative movement between the needle cylinder and feeders, said control means further including feeder register means activated in response to feeder signals from said encoder means for providing a series of coded feeder count signals which are indicative of the feeder in which a predetermined needle on the needle cylinder is located during a revolution of relative movement between the needle cylinder and feeders.

3. A knitting machine for use in knitting a selected one of a plurality of patterns, said machine comprising a needle cylinder, a plurality of needles disposed on said needle cylinder in a circular array which begins with a first needle and ends with a last needle, a plurality of feeders disposed about said needle cylinder for feeding strands of material to said needles, actuator means in each of said feeders for effecting operation of said needles to knit the strands of material into a pattern, drive means for effecting relative rotation between said feeders and said needle cylinder and for effecting sequential cooperation between each of said feeders and each of said needles in turn such that each of said feeders is associated in turn with each of said needles on said needle cylinder, encoder means for providing signals which vary with variations in the relative position of said needle cylinder and feeders, said encoder means including first circular code track means, first reader means cooperating with said first circular code track means to provide binary coded feeder signals which vary with relative movement between said feeders and needle cylinder, second circular code track means distinct from said first circular code track means, and second reader means distinct from said first reader means cooperating with second circular code track means to provide binary coded revolution signals which vary with relative movement between said feeders and needle cylinder, control means for receiving signals from said encoder means and for effecting activation of said actuator means to knit a pattern during relative movement between said needle cylinder and feeders, said control means including feeder register means activated in response to feeder signals from said. first reader means means for arithmetically operating on said binary coded feeder signals to provide a series of binary coded feeder count signals indicative of the particular feeder with which said first needle is associated during relative rotation between said needle cylinder and feeders and which binary coded feeder count signals vary in response toa change in the feeder with which said first needle is associated, said control means including revolution register means activated in response to said binary coded revolution signals from said second reader means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders.

4. A knitting machine as set forth in claim 3 wherein said revolution register means includes means for sequentially repeating said series of coded revolution count signals each time a predetermined number of revolutions of relative rotation occurs between the needle cylinder and feeders during operation of the knitting machine and a plurality of circuit means which are selectively activatable to conduct signals from said plurality of reader means to said revolution register means, for effecting a knitting of a selected one of the plurality of patterns each time said series of coded revolution count signals is repeated by said revolution register means, and selector means for varying the predetermined number of revolutions required to effect a repetition of said series of coded revolution count signals by said revolution counter means to enable the knitting machine to knit patterns requiring different numbers of revolutions of relative rotation between the needle cylinder and feeders, said selector means including switching means for activating predetermined combinations of said circuit means to effect a repetition of said series of revolution count signals by said revolution register means in a number of revolutions corresponding to a selected one of the plurality of patterns.

5. A knitting machine for knitting any one of a plurality of different patterns, said machine comprising a needle cylinder, a plurality of spaced apart needles disposed on said needle cylinder and arranged in a circular array extending between a first needle and a last needle, a plurality of feeders disposed about said needle cylinder for feeding strands of material to said needles, said feeders being associated with each other in feeder groups comprised of a number of feeders which is variable to correspond to a selected pattern, drive means for providing relative movement between said needle cylinder and feeders to enable said first needle to be associated with each of said feeders in turn, encoder means for providing signals which vary with relative movement between said needle cylinder and feeders, said encoder means including first code track and reader means for providing needle signals which vary in response to relative movement between said needle cylinder and feeders by an extent corresponding to the spacing of adjacent needles, second code track and reader means for providing coded feeder signals which vary in response to relative movement between said needle cylinder and feeders by an extent which is a function of the spacing of adjacent feeders, said coded feeder signals being indicative of the feeder with which said first needle is associated, and third code track and reader means for providing coded revolution signals which vary in response to relative movement between said needle cylinder and feeders by an extent which is a function of one complete revolution of relative movement, said coded revolution signals being indicative of the number of revolutions of relative movement which have occurred between said needle cylinder and feeders during the knitting of a pattern, and control means for receiving said needle signals, coded feeder signals, and coded revolution signals from said encoder means and for effecting activation of said needles during relative rotation between said needle cylinder and feeders, said third code track and reader means including one code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of said one code track being of the same longitudinal extent, another code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of a first characteristic of said other code track being of the same longitudinal extent as one of said zones of said one code track and each of said zones of a second characteristic of said other code track having a longitudinal extent which is greater than the longitudinal extent of one of said zones of a first characteristic of said other code track, a first reader for cooperating with each of said zones of the first characteristic of said one code track in turn to provide a signal of a first level during relative rotation between said needle cylinder and feeders for a first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said one code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for said first predetermined number of revolutions, and a second reader for cooperating with each of said zones of a first characteristic of said other code track in turn to provide a signal of a first level during relative rotation between said needle cylinder and feeders for said first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said other code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for a second predetermined number of revolutions which is greater than said first predetermined number of revolutions, said control means including switching means for enabling said control means to utilize signals from said first reader during the knitting of a pattern requiring a first predetermined number of revolutions of relative movement between the needle cylinder and feeders and for enabling said control means to utilize signals from said second reader during the knitting of a pattern requiring a second predetermined number of revolutions of relative movement between the needle cylinder and feeders.

Claims

1. Apparatus for use in a knitting machine having a needle cylinder holding a plurality of needles to which strands of material are fed from feeders during relative rotation between the needle cylinder and feeders to knit a predetermined one of a plurality of different patterns the knitting of each of which requires different numbers of revolutions of relative rotation between the needle cylinder and feeders with the feeders associated with each other in groups of any one of a plurality of different sizes, wherein said apparatus comprises encoder means for providing signals which vary with variations in the relative position of the needle cylinder and feeders and for providing revolution signals which vary with revolutions of relative rotation between the needle cylinder and the feeders, said encoder means includes a first code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of said first code track being of the same longitudinal extent, a second code track having a plurality of zones of the first characteristic and a plurality of zones of a second characteristic, each of said zones of a first characteristic of said second code track being of the same longitudinal extent as one of said zones of a first characteristic of said first code track and each of said zones of a second characteristic of said second code track being of a longitudinal extent which is at least twice as great as the longitudinal extent of one of said zones of a second characteristic of said first code track, first reader means for cooperating with each of said zones of the first characteristic of said first code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for a first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said first code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions, and second reader means for cooperating with each of said zones of a first characteristic of said second code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said second code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for a second predetermined number of revolutions which is at least twice as great as said first predetermined number of revolutions, control means for receiving signals from said encoder means and for effecting activation of the needles during relative rotation between the needle cylinder and feeders, said control means including revolution register means activated in response to revolutioN signals from said encoder means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders and for sequentially repeating said series of coded revolution count signals each time a predetermined number of revolutions of relative rotation occurs between the needle cylinder and feeders during operation of the knitting machine, means for effecting a knitting of a selected one of the plurality of patterns each time said series of coded revolution count signals is repeated by said revolution register means, and selector means for varying the predetermined number of revolutions required to effect a repetition of said series of coded revolution count signals by said revolution register means to enable the knitting machine to knit patterns requiring different numbers of revolutions of relative rotation between the needle cylinder and feeders, said selector means including switching means for effecting a transmittal of signals from said first reader means to said revolution register means during the knitting of a pattern requiring a first predetermined number of revolutions of relative movement between the needle cylinder and feeders and for effecting transmittal of signals from said second reader means to said revolution register means during the knitting of a pattern requiring a second predetermined number of revolutions of relative movement between the needle cylinder and feeders.

3. A knitting machine for use in knitting a selected one of a plurality of patterns, said machine comprising a needle cylinder, a plurality of needles disposed on said needle cylinder in a circular array which begins with a first needle and ends with a last needle, a plurality of feeders disposed about said needle cylinder for feeding strands of material to said needles, actuator means in each of said feeders for effecting operation of said needles to knit the strands of material into a pattern, drive means for effecting relative rotation between said feeders and said needle cylinder and for effecting sequential cooperation between each of said feeders and each of said needles in turn such that each of said feeders is associated in turn with each of said needles on said needle cylinder, encoder means for providing signals which vary with variations in the relative position of said needle cylinder and feeders, said encoder means including first circular code track means, first reader means cooperating with said first circular code track means to provide binary coded feeder signals which vary with relative movement between said feeders and needle cylinder, second circular code track means distinct from said first circular code track means, and second reader means distinct from said first reader means cooperating with second circular code track means to provide binary coded revolution signals which vary with relative movement between said feeders and needle cylinder, control means for receiving signals from said encoder means and for effecting activation of said actuator means to knit a pattern during relative movement between said needle cylinder and feeders, said control means including feeder register means activated in response to feeder signals from said first reader means means for arithmetically operating on said binary coded feeder signals to provide a series of binary coded feeder count signals indicative of the particular feeder wiTh which said first needle is associated during relative rotation between said needle cylinder and feeders and which binary coded feeder count signals vary in response to a change in the feeder with which said first needle is associated, said control means including revolution register means activated in response to said binary coded revolution signals from said second reader means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders.