US2422568A - Electronically controlled knitting machine - Google Patents

Description

June 17, 1947. w LARKlN. 2,422,568

ELECTRONICALLY CONTROLLED KNITTING MACHINE June 17 1947 w. LARKIN 2,422,568

LECTRONICALLY CONTROLLED KNITTING MACHINE Filed \0ct. 5, 1945 4 Sheets-Sheelt 2 W. LARKIN `une 17, 1947.

ELECTRONICALLY CONTROLLED KNIT'IING MACHINE "Filed oct. 3,' 1945 y 4 sheets-sheet 5 F fe.

June 17, 1947. W LARKIN l 2,422,568

ELECTRONICALLY CONTROLLED KNITTING MACHINE Filed Oct. 5, l1945 4 Sheets-Sheet 4 Patented .une 17, 1947 ELECTRONICALLY CONTROLLED KNITTING MACHINE Walter Larkin,

Norristown, Pa.,

assignor, by

mesne assignments, to Fidelity Machine Company, Inc., Philadelphia, Pa., a corporation of Pennsylvania Application October 3, 1945, Serial No. 620,114

12 Claims.

This invention relates to variable speed drives for knitting machines, and particularly to drives for circular knitting machines adapted for knitting seamless hosiery in tubular strip form, wherein each stocking unit includes a welt section, a leg section, a heel pocket, a foot section, a toe pocket and in most cases a separation or ravel section between units.

During the knitting of these different parts of each stocking unit it is frequently necessary to change yarns or to add reinforcing yarns. During such changes of yarns, or the feeding or reinforcing yarns, and during the reciprocating action of the needle cylinder or the cam ring associated therewith, and the corresponding reciprocating action of the sinker ring while knitting the heel and toe pockets, it has been found to be desirable to Vary the knitting speed in relation to the normal knitting speed employed in the circular knitting of the leg and foot portions of the stocking unit.

Also in knitting stocking strips from different base yarns, such as natural thread silk, artificial silk, mercerized cotton, rayon, nylon or other synthetic lament yarns, it has been found advisable to establish a predetermined base speed for each of these types or qualities of yarn and to vary the speeds for knitting the different parts of each stocking unit from the established base speed in order to produce the highest quality fabric at the greatest possible speed.

These various speeds during the knitting of the different parts of a stocking unit have been deemed necessary to prevent damage to the needles, sinkers and other related parts of the machine and to the fabric `in order to prevent stoppages resulting from broken or bent needles, etc., and in order to give a uniform stitch and a consequent uniform fabric free of needle or sinker marks.

The change speed mechanism of a circular knitting machine normally affords a high speed for continuous circular knitting and a slow speed for reciprocating knitting, but no variation in speed for yarn changing, yarn reinforcing, or for knitting dierent kinds and/or weights of yarn.

The principal object of the present invention is to provide a very sensitive and readily variable speed mechanism to an. ordinary circular hosiery knitting machine, whereby the knitting speed of the machine may be quickly and automatically changed and varied to any desired extent with respect to the base speed established for knitting of the particular kind or weight of yarn of which the major portion of the stocking strip is to be formed.

For the purposes of the present invention the type of change speed mechanism best suited for putting into effect the objects of the present inventon is what is popularly termed the electronic motor control such as disclosed in the following patents of the General Electric Company, through which such units are commercially available, i. e. U. S. Patents No. 1,654,949, No. 1,654,989, No. 1,655,036, No. 1,655,040, No. 1,719,866, No. 1,847,- 934, No. 1,851,692, No. 1,904,485.

1n the present case no claim is made to this so-called electronic control unit per se but only as to its application to a circular knitting machine broadly and more specically to a circular knitting machine equipped with an ordinary pattern drum by which the shifting from the continuous circular knitting to reciprocating knitting and vice versa are controlled and by which a plurality of yarn lingers are selectively moved into and out yarn feeding relation to the needles and sinkers of the machine for effecting yarn changes and reinforcements etc.

These electronic control units are in themselves controlled, in the commercial adaptations thereof, by a rotary type potentiometer, and in the present instance the potentiometer is controlled vby the pattern drum of the knitting machine, whereby, as the pattern drum is intermittently rotated step by step a speed-control cam thereof will control the position of the rotor element of the potentiometer with respect to the stator element thereof to vary the speed of the knitting machine in accordance with` the current operation of the machine as directed by the pattern drum.

In the accompanying drawings:

Fig. l is a more or less diagrammatic side elevation, partly in section, of suicient of a conventional type of circular hosiery knitting machine to illustrate the present invention, and as would be Viewed along the line I--l, Fig. 2;

Fig. 2 is a vertical sectional elevation as taken on the line 2-2, Fig. 1;

Fig. 3 is a diagrammatic planar development of the peripheral surface of the pattern drum shown in Figs. 1 and 2;

Figs. 4 and 5 illustrate a detail of the invention and show the means for establishing a base speed for the. knitting machine for one predetermined kind of knitting yarn;

Fig. 6 is a diagrammatic View showing the motor circuit control unit as being operated directly from the pattern chain of the machine, and

Fig. 7 is an elementary circuit diagram for controlling the speed of the 'driving motor of the knitting machine.

As shown in the drawings the cam ring 2 of the knitting machine, in the present instance, is held stationary and is rigidly secured to the top frame l of the knitting machine. The knitting or needle cylinder 3 is of the rotary type and is adapted to rotate about a vertical axis within the cam ring 2. The sinker ring mechanism is illustrated generally at il.

The needle cylinder 3 is provided with an integral bevel gear which meshes with and is rotated by a bevel gear 5, which latter is iixedly mounted for rotation on a horizontal shaft 'I. The shaft I is rotatably mounted in suitable bearings in opposite side frame members 8 and 9 of the machine.

Loosely mounted for rotation about the aXis of the shaft at opposite ends respectively of the hub ID of the bevel gear 6, are spur gears II and I2 respectively. The spur gear I2 meshes with a spur gear I3 which is rotatably mounted on a fixed stud shaft I4 carried by the side frame member 8. rlhe gear I3 meshes with a pinion I5 which is fixed to a jack shaft I6 having one end rotatably supported inthe frame member 8 and its opposite end rotatably supported in a bracket I'I carried by the base frame I 8 of the machine. f

Secured to the jack' shaft I 5 is a second spur gear IB which meshes with a spur gear 20. The spur gear 2G is secured to a take-off shaft ZI which is rotatably mounted in the bracket II and a corresponding bracket IIa on the base frame I8. p

Secured to the take-off shaft 2l is a bevel gear 22 which meshes with a bevel pinion 23, which latter is secured to the rotor shaft 24 of an electric driving motor 25, said motor being rigidly fixed in and to the base frame I8 of the knitting machine.

The spur gear I3, referred to above, is provided with a crank pin 2S on which is rotatably mounted one end boss or hub 21 of a pitman 28, the opposite end hub 29 of which is rotatable on a pin 3 secured in one arm 3l vof a gear segment lever 32. The lever 32 is secured to one end of a shaft 33 which is Ymounted for oscillation in the framework of the machine. The lever 32 includes a gear segment 34 which is constantly in mesh with the'spur gear II at one end of the hub I I! of `the bevel gear which .drives the cylinder 3 through the bevel gear 5. Y

The hubl Ill of fthe gear 6 is splined axially at 35 for reception and operation of a sliding clutch key 35. The key 35 is carried by a sleeve 31 which is slidably vmounted on the outside of the hub I and is provided with an annular circumferential groove 38 for reception of a clutch yoke 39.

The clutch yoke `39 is pivotally carried in the outer end of a clutch shifting lever 40 which latter is pivotally'mounted on a pinplll in a boss 42 on the under side of the top frame I of the machine. l

The clutch key 35 is shiftable longitudinally in the spline 35 of the gear hub I ll, into end grooves 23 and 44 in the gears I'I and I2 respectively, so that the h-ub It may be rigidly coupled to the gear II for oscillating the needle cylinder 3 or to thegear I2 for rotating the cylinder 3.

The shifting of the clutch key 35 is effected by cam plates 55, 45, 'lil and 48 secured to the peripheral surface 49 of the pattern drum 5i).

The pattern drum 5U is secured to a shaft 5I which is rotatably mounted in the framework of the knitting machine. Secured to the shaft 5I is a, ratchet wheel '52 which is engageable by a paWl "53 for advancing the pattern drum 5i) step The pawl 53 is pivotally mounted on a lever 54 which is secured to the shaft 33. This'shaft 33 is continuously oscillated through the arm'SI and 4 pitman 28 from the crank pin 26 on the continuously rotating gear I3.

The pawl 53 is held out of mesh with the ratchet wheel 52, at predetermined intervals by a kick-out arm or latch 55 Which is pivotally mounted on the frame and operates against a pin 55 which projects laterally from the pawl 53. The latch l55 in turn is controlled by high links of a pattern chain (not shown) which rides on a chain wheel '5l' engaging one arm 58 of the latch 55.

The chain Wheel 5l is freely rotatably mounted on the pattern drum shaft 5I and is advanced step by step by a ratchet wheel 59 which is secured to the chain wheel 5l for rotation therewith. The ratchet wheel 59 is advanced step by step by a paw] Et pivotally mounted on the pawl lever 5d secured to' the constantly oscillating shaft 33.

On the peripheral face 129 of the pattern drum 55 is a plurality of segmental circumferentially arranged and laterally spaced cam piece series 6I, 5I, which control the operation of a plurality of yarn change lingers 52, 52 etc. through lift levers 53, 63 respectively. These lift levers 63, 63 are pivotally mounted on a cross shaft 54, which is non-rotatably mounted in the frameworkv of the knitting machine.

Pivotally mounted on the shaft 64 is a lever 65 on which is rotatably mounted a cam follower roller 65.' rhis cam follower 55 is adapted to ride high, low and intermediate lifts 67a, B'Ib, 61o, of a ring cam @l secured to one end of the pattern drum 52. There may be as many of these lifts as there are speed variations required of the driving motor 25 during the knitting of a complete repeat in the string of stocking units knitted by the needles (not shown) operating in the needle grooves of the cylinder 3 by the cams (not shown) in the cam ring 2.

The speed Variations of the driving motor 25 are controlled by the electronic unit referred to above as being disclosed in one or more of the prior U, S. patents listed above.

The electronic control unit in turn is controlled by a potentiometer l, see F'igs. 4 and 5, which includes an outer casing 'II which for the purposes of this disclosure will be termed the stator, and an internal element secured to a shaft 'I2 which will be hereinafter referred to as the rotor.

'The specific construction of the potentiometer 'MI need not be shown or described in l'detail as it is of va conventional type well known as to construction and mode of operation by anyone having the most elementary knowledge of electricity.

For the purpose of this invention, the stator 1I is axially aligned and concentric with the rotor shaft 'I2 of the potentiometer 'le and the 'shaft I2 is rotatably mounted in a bearing 'i3 mounted in a bore 'Iii formed in the side frame 8 of the knitting machine.

In order to retain the stator in a fixed predetermined position for setting the potentiometer for :maintaining the speed of the motor 25, through the electronic unit disclosed in theaforesaid prior U. S. patents, at a predetermined number of revolutions per minute, a's a base speed for anygiven knitting yarn, the stator is secured to an arm i5 having a spring pressed detent i6 at its outer end for entering one of a plurality of openings il, 'Il formed in the side frame 3, so that the stator 'II may be bodily turned about the axis of the rotor shaft 'I2 to any one of the angular positions determined by the location of the keeper holes TI.

'The rotor, as is common in potentiometers, is adapted to be turned within the stator to increase or decrease the Voltage of the line of the electric circuit in which the potentiometer is installed, depending upon the direction in which the rotor is turned, and in order to effect such turning of the rotor within the stator 1i the rotor shaft 12 is provided with a spur pinion 118 Which meshes with a gear segment 19, which latter is rigidly secured to the lever 65. The lever 65 as previously noted carries the cam follower et and this cam follower is maintained in constant contact with the speed control cam 61 by a spring 80.

From the forego-ing description, it will be clear that once a base speed for the motor 25 is established for a given knitting yarn, by inserting the spring pressed detent 16 in one of the keeper holes 11, greater or lesser speeds of the motor 25 may be attained by turning the rotor shaft 12 of the potentiometer with respect to the stator, i. e. turning the shaft 12 in one direction will effect an increasein the speed of the motor 25 and turning the shaft 12 in the opposite direction will effect a decrease in the speed of the motor 25.

It will also be clear that the speed changes of the motor 25 are coordinated with the various mechanical changes etc. in the operation of the knitting machine as determined by the step by step movements of the pattern drum 5B, by reason of the fact that the high, low and intermediate lobes of the speed change cam 61 bear definite xed relation to the cam segments #l5 to e8 and Gl, 5I on the pattern drum 50 by which such mechanical changes in the operation of the knitting machine are controlled. Y

It will also be clear that by varying the relative heights of the lobes on the speed change cam 61 and distributing them discriminately around the circumference of the pattern drum 5) an infinite number of relatively dfferent speeds, Within a given bracket, may be caused to be effected by the motor 25; and that by changing the position of the stator about the axis of the rotor shaft these speed brackets may be changed in accordance with the different knitting yarns employed, or for other reasons if desired.

As shown in Fig. 6, the potentiometer 'it may be controlled directly from the pattern chain of Y is actuated by a pinion 1e on the rotor shaft 12 thereof, and this pinion 18 meshes with a gear segment 1S loosely mounted on the shaft te. In the present instance, Fig. 6, the gear segment 19a is secured to one end of a cross shaft 64a and the cam follower arm 65 of Fig. 1 is replaced by an arm 65a. secured to the distant end of the shaft 64a. This arm 65a has its outer end shaped to ride the high, low and intermediate links 81a, 81h, 81C of the pattern chain 81 to rock the shaft 6M to varying degrees for correspondingly oscillating the roto-r of the potentiometer.

Fig. '1 sho-Ws the electronic circuit for controlling the speed of the motor 25, through the adjustment of the potentiometer 10. The motor armature is represented at 9G, while the motor field is represented at 9i. The field current is sup-plied from a transformer 92' by means of a full wave rectiiier 93, while the armature is supplied with current from the transformer 52 through a pair of controlled rectiers 94 and 95. As indicated, the tubes 93, 94, and 95 are gaslled tubes. The potentiometer 1 serves in con- `junction with a tube 96 and a potentiometer 91 to control the operation of tub-es 9:1 and 95 through the grid circuits thereof designated generally by reference character 98. The details of operation are unimportant here, since the electronic control circuit is old per se and the present invention is concerned only with theoperation of the potentiometer 10 by the pattern mechanism of the knitting machine.

I claim:

1. A circular knitting machine comprising an individual electric driving motor, pattern mechanism for governing predetermined operations of said machine, an electronic speed control circuit for and including said motor, a variable control unit for said circuit, and means coordinated with said pattern mechanism for operating said variable control unit for varying the speed of said motor in accordance with changes in the operations of said machine as prescribed by said pattern mechanism.

2. A circular knitting machine comprising a pattern drum for governing predetermined operatio-ns of said machine, an individual electrie driving motor for said machine, an elec tronic speed control circuit for and including said motor, a variable control unit for and forming part of said circuit, said variable unit comprising a normally fixed element and a relatively rotatable element, means for turning said rotatable element relative to said fixed element including a cam follower, and a cam comprising a plurality of lobes of different heights carried by said pattern drum andy engageable with said cam follower for actuating said unit to eiect variations in the speed of said motor in accordance with variations in the operations of said machine as prescribed by said pattern drum.

3. A circular knitting machine comprising a pattern drum for governing predetermined oper.- ations of said machine, an individual electric driving motor for said machine, an electronic speed control circuit for and including said motor, a variable control unit for and forming part of said circuit, said variable unit comprising a normally Xed element and a relatively rotatable element, means for turning said rotatable element relative to said fixed element including a cam follower, a cam comprising a plurality of lobes of different heights carried by said pattern drum and engageable with said cam vfollower for actuating said unit to effect variations in the speed of said motor within a predetermined range in accordance with variations in the operations of said machine as prescribed by said pattern drum, and manually operable means for varying the position of said normally fixed element about the axis of rotation of said rotatableelement for varying said range as a `whole from one bracket of speed variations of said motor to another such bracket.

4. A circular knitting machine comprising an individual electric driving motor adapted to rotate in one predetermined direction, a pattern drum for governing predetermined operations of said machine, an electronic speed control circuit for controlling the lspeed of said motor in said direction solely, and means carried by said pattern drum for controlling said circuit to change 7 the speed of said motor in said direction solely in accordance with changes in the operations vof said machine as prescribed by said pattern drum.

5. A circular knitting machine comprising an individual electric driving motor, a pattern drum for governing predetermined operations of said machine, a variable unit for controlling the speed of said motor, said unit comprising a normally Xe'd =element and a relatively rotatable element, a lever for rotating said rotatable element, and a cam carried by said pattern drum for rocking said lever and thereby actuating said unit to change the speed lof said mot-or in accordance with changes in the operations of said machine as prescribed by said pattern drum.

6. A circular knitting machine comprising an individual electric driving motor, a pattern drum for governing predetermined operations of 'said machine, a variable unit for controlling the speed of said motor, said unit comprising a-normally xed element and a relatively rotatable element, a lever for rotating said rotatable element, a cam carried by said pattern drum for rocking said lever and thereby actuating said unit to change the speed of said motor in accordance Withl changes in the operations of said machine as prescribed by said pattern drum, and manually operable means for rotating said normally fixed element to vary the range of speed lchanges of said motor.

'7. A circular knitting machine comprising a pattern drum for governing predetermined operations of said machine, an individual electric motor for driving said machine, a potentiometer for varying the speed oi said motor, and means on said pattern drum for actuating -said potentiometer to change `the speed of said motor in accordance with operational changes of the machine as prescribed by said pattern drum.

8. A circular knitting machine comprising a pattern drum for governing predetermined opere ations of said machine, an individual electric motor for driving said machine, a potentiometer for varying the speed of said motor and comprising a rotor shaft, a pinion on said shaft, a gear segment meshing with said pinion, a lever cor1 centric with and integrally connected to said gear segment for concurrent pivotal movement about a xed axis, a cam follower on said lever, and `a ring cam secured to said pattern drum `and including a plurality of lobes of different heights spaced circumferentially around said drum for successively contacting said cam follower to'actuate said potentiometer for varying the speed kof said motor in 'accordance with operational changes of said machine as prescribed by said lpattern drum.

'9. A circular knitting machine comprising a pattern drum for governing predetermined operations of said machine, an individual electric motor for driving said machine, a potentiometer for varying the speed of said motor and comprising a rotor shaft, a normally iixed stator encircling said rotor shaft, a pinion on said shaft, a gear segment meshing With'said pinion, a lever concentric with and integrally-connected to said gear segment for concurrent pivotal vmovement about a fixed axis, a cam follower on said lever, a ring cam secured to said pattern drum and including a plurality of lobes 0f different heights spaced circumierentially around said drum for successively contacting said cam follower to actuate said potentiometer for varying the speed of said motor in accordance with operational changes of said machine as prescribed by said pattern drum, an operating arm on said stator,

and a manually operabl'edetent on the 'outer end of said arm adapted to be selectively entered into a plurality of fixed relatively spaced keeper holes formed in said machine for varying the speed ranges of said motor within predetermined brackets respectively .in accordance with the keeper hole entered by said detent.

10. iA circular knitting machine comprising a pattern drum for governing predetermined operations of said machine, an individual electric motor for driving said machine, a potentiometer for varying the speed of said motor and comprising a rotor Shaft, a normally xed stator encircling said rotorxshaft, a pinion on said shaft, a gear segment meshing With said pinionfa lever concentric with and integrally connected to said gear segment for concurrent pivotal movement about a xed axis, a cam follower on said lever, a ring cam secured to said pattern drum and including a plurality of llobes of different heights spaced 'circumferentially around said drum for successively contacting said cam follower to actua-te said Apotentiometer for varying the speed of said motor in accordance 'with operation-al Achanges of said machine as prescribed by said pattern drum, an operating larm on said stator, a manually operable detent on the outer end of said arm adapted to be selectively entered into a plurality of xedrelatively spaced keeper holes formed in said machin-e for varying the speed ranges of said motor Within predetermined brackets respectively in accordance with the keeper hole entered by said detent, and an electronic motor control lcircuit includingsaid driving motor and said potentiometer forgoverning the speed of said motor in accordance with the circumferential relationship of said rotor shaft and said stator as prescribed .by said detent and said ring cam.

11. A circular knitting machine comprising an individual electric driving Ymotor therefor adapted to -rotate in one predetermined direction, pattern ,mechanism for governing predetermined operations of said machine, an electronic speed -control circuit for varying the speedfof said motor in said direction solely, and means carried by said pattern mechanism for controlling said circuit.

12. A circular knitting machine comprising an individual electricV driving motor therefor adapted 'to 'rotate in one `predetermined direction, pattern mechanism including 'a link chain `lor 'governing predetermined `-operations of said machine, an electronic speed control circuit `for controlling the speed of said Vmotor n'said direction solely, and a series of links of different heights included in said pattern chain for controlling said circuit to vary the speed of said motor in said direction solely. a

WALTER LARK'IN.

REFERENGES CITED The following vreferences are of record in the le of this patent:

U-NTTED STATES PATENTS Number i Name Date 1,123,779 Moller Jan. 5, 1915 2,068,609 Richter Y Jan. 19, 1937 FOREIGN 'PATENTS Number Country Date 1397,793 Great Britain Aug. 31, 1933 172,357 Great Britain NoV. `30, 1921 439,713 Germany Jan, 1-8, l1927

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