US3197977A - Yarn clamping and severing mechanism for multi-feed circular knitting machines - Google Patents

Description

1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR 'KNITTING MACHINES ll Sheets-Sheet 1 Filed Feb. 5. 1960 M M a l I h p Re m WW I I a S M h 1 m w "b. w l m J I m H I 1 6 a. f 1 F 3 1 m a w a w? m 1 w -111--- 1-- M w x w NJ) AU 1 3 H L I W m Q an". fl n H n In... M 7 w F x I o .w x l v m 1 B I 0 3 2 Z 1 a .w w a W a a 2 a fi M 0 M H 5 a J y a 0 6 a G o b 9 M I I! I 8? l M w 70 5 1 F r l4 l8 67 0 Ea M 9 a Aug. 3, 1965 v. 'r. STACK 97,

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED' CIRCULAR KNITTING MACHINES Filed Feb. 5. 1960 ll Sheets-Sheet 2 INVENTOR.

I Z'mm Israeli;

QM; @J

ATTORNEYS.

Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5, 1960 ll Sheets-Sheet 3 INVENTOR.

ATTORNEYS.

Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5. 1960 ll Sheets-Sheet 4 INVENTOR.

Var/101i 2191 6017} BY Qua]: 1

A TTORNEYS.

3,197,977 FEED V. T. STACK Aug. 3, 1965 YARN CLAMPING AND SEVERING MECHANISM FOR MULTI- CIRCULAR KNITTING MACHINES ll Sheets-Sheet 5 Filed Feb. 5. 1960 INVENTOR. Var/1011 ZLS'Zac Z Aug. 3, 1965 v. 'r. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5. 1960 ll Sheets-Sheet 6 FIG: 14.

IN VENTOR.

Var/2012 2257607,

A TTORNEYS.

Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5, 1960 ll Sheets-Sheet 7 INVENTOR.

als 6 ml A TTORNEYS.

Aug. 3, 1965 v. T. STACK 3, 77

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5. 1960 11 Sheets-Sheet 8 FIG. 30.

INVENTOR.

Var/2m T820017,

A TTORNEYS.

Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5, 1960 11 Sheets-Sheet 9 INVENTOR.

YS. 13 ATTORNE Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Filed Feb. 5. 1960 ll Sheets-Sheet 10 16a FI6 Z3 16{ g INVENTOR.

A TTORNEYS.

Aug. 3, 1965 v. T. STACK 3,197,977

YARN CLAMPING AND SEVERING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES 11 Sheets-Sheet 11 Filed Feb. 5. 1960 INV EN TOR.

ATTORNEYS.

United States Patent 3,i7,977 YARN CLAMPXNG AND SEVERING MECHANISM FOR MULTi-FEED CIRCULAR KNITTING MA- CHINES Vernon T. tack, Winston-Salem, N.C., assignor, by mesne assignments, to The Gordon Company, Winston-Salem, N.C., a partnership Filed Feb. 5, 1960, Ser. No. 7,035 1 Claim. (til. 66140) This invention relates to circular knitting machines. More particularly, this invention pertains to yarn clamping and severing mechanisms for multi-feed circular knitting machines used in the commercial production of seamless hosiery. 1

In the knitting of seamless hosiery, it is customary to form different parts of the stockings from yarns of different deniers, and frequently certain types of yarn are used in certain parts of the stockings, but are not used in other parts thereof. Accordingly, it is generally necessary to make several yarn changes during the knitting of a seamless stocking by withdrawing one yarn from action and substituting another yarn in its place, or by adding a second yarn to the yarn that is being fed to the knitting machine. This is particularly true of the use of multi-feed knitting machines, which are often used to knit yarns of a different character into the stocking fabric.

With the conventional yarn clamping and severing mechanisms for multi-feed machines, several trailing yarn ends of considerable length are left attached to the stocking fabric, following knitting, as a result of the various yarn changes whichoccur, during knitting. Such yarn ends are unsightly, and must be removed. To remove these yarn ends, it has heretofore been necessary for mill personnel to manually clip each yarn end from the stocking fabric. Such manual clipping operation is both time consuming and expensive, and the additional handling of the stockings necessitated thereby subjects the stockings to a high possibility of damage.

The chief object of this invention is to obviate the above drawbacks by providing novel means for severing the various yarns used in the knitting of seamless hosiery on multi-feed circular knitting machines sufiiciently close to the stocking fabric to dispense entirely with the manual clipping operation.

A further object of this invention is to provide a novel yarn clamping and severing mechanism for niulti-feed circular knitting machines which comprises a separate yarn clamp and a separate yarn cutter for each yarn feeding station of the machine, whereby the yarns fed from each station will be securely clamped while inactive, will be properly tensioned during severing, and will be severed close to the needle circle, thereby leaving only a short, inconspicuous yarn end trailing from the knitted fabric.

A further object of this invention is to provide a yarn clamping and severing mechanism for multi-feed circular knitting machines wherein the yarns introduced to the needles will be maintained under tension until severed from the trailing portions thereof clamped within the needle circle.

A further object of this invention is to provide a yarn clamping and severing mechanism for multi-feed circular knitting machines having separate yarn clamps and separate yarn removal means disposed adjacent each yarn clamp to remove from within the needle circle the severed ends of yarn which are produced following the introduction of yarn to the needles.

A further object of this invention is to provide a yarn clamping and cutting mechanism for multifeed circular knitting machines wherein there is provided suction means for removing loose yarn ends from within theneedle circle and further including means for actuating the yarn c CC clamps and suction means simultaneously to release and remove the yarn ends.

Other objects and advantages of this invention will be apparent from the following detailed description of the attached drawings, wherein: I

FIG. 1 is a fragmentary, partially diagrammatic view in perspective of a multi-feed circular knitting machine embodying this invention.

FIG. 2 is a fragmentary view in perspective of the transfer mechanism and associated parts as seen from the left-hand side of FIG. 1.

:FIG. 3 is a fragmentary view in'top plan of the transfer mechanism and associated parts.

FIG. 4 is an enlarged fragmentary view in perspective of the transfer cap and of the yarn tensioning and removal means for the main yarn feed showing a cut portion of yarn in process of removal.

FIG. 5 is an exploded view of FIG. 4.

FIG. 6 is an enlarged fragmentary view in perspective of the transfer cap and of the yarn tensioning and removal means for the auxiliary yarn feed showing a cut portion of yarn in process of removal.

FIG. 7 is an exploded view of FIG. 6.

8 is an enlarged fragmentary view in section of the yarn cutter for the main yarn feed showing the cutter in operative position.

FIG. 9 is a sectional view taken in the direction of the angled arrows IX--IX of FIG. 8.

FIG. 10-is a view similar to FIG. 8 showing the yarn cutter in inoperative position.

FIG. 11 is an enlarged fragmentary view in section taken as indicated by the angled arrows XI-XI in FIG. 2.

FIGS. 12 and 13 are sectional views taken in the direction of the angled arrows XII-XII of FIG. 3 showing the operation of yarn cutter for the auxiliary yarn feed.

FIG. 14 is an enlarged fragmentary view in elevation looking in the direction of the arrow XIV in FIG. 1.

FIG. 1-5 is a fragmentary view looking in the direction of the angled arrows XVXV of FIG. 14.

FIGS. 16 to 20 inclusive show a modification of the invention.

FIGS. 21 to 26 inclusive are fragmentary diagrammatic views in plan illustrating the operation of this invention.

This invention is adaptable to any type of multi-feed circular knitting hosiery machine. F or example, with respect to ladies hosiery, the invention may be readily adapted for use in connection with the Scott & Williams Model KN machine having 'a two feed attachment, or the Scott & Williams Model KN-II machine, or the Reading- Booton twin-feed ladies seamless hosiery machines. In the drawings, for convenience of illustration, the invention is shown as adapted to the well known Scot-t & Williams Model KN independent needle circular knitting machine for ladies hosiery having the conventional two feed attachment.

Referring to FIGS. 1, 2 and 3, there is shown the usual transfer mechanism comprising the rotatable transfer dial 10 which supports, in a plurality of radial guide grooves, the usual transfer instrumentalities or bits 11. The transfer dial 10 is rotated in harmony with the rotation of the needle cylinder (not shown) by the usual drive means indicated generally at 12 in FIG. 1.

Mounted on the transfer dial 10, above the transfer instrumentalities 11, is a toothed annulus 13 similar to that shown in Stack and Knox U.S. Patent No. 2,824,436, issued February 25, 1958. The annulus 13 is connected to the transfer instrumentalities in the manner disclosed in said Patent No. 2,824,436, and thus is caused to rotate with the transfer dial 10. Mounted above the annulus 13 and the transfer instrumentalities 11 is the usual stationary transfer cap 14 (sometimes called the dial cap) having 3. the usual upstanding hub 14a through which passes the rotatable spindle 12a for driving the transfer dial 10.

The needle circle of the machine is indicated schenratically by the broken circle 15 in FIG. 3 and the main yarn feeding station is indicated generally at 16. The main yarn feed 16 includes a plurality of individually retractable interchangeable yarn feeding fingers, of which one, designated as 16a, is shown. The auxiliary yarn feeding station is indicated generally at 17, and it also may comprise a plurality of individually retractable interchangeable yarn feeding fingers, one of which, designated 17a, is shown. Each of the two yarn feeds 1 6 and 17 has associated therewith a yarn clamp, a yarn cutter and a suction means for removing severed ends of yarn. Preferably, the auixiliary yarn feeding station 17 is angularly spaced from the main yarn feeding station 16 on the order of from 70 to 130 in the direction of needle rotation.

The yarn handling mechanism for the main yarn feed 16 will now be described. Mounted upon the transfer cap 14, so as to be disposed slightly above the upper surface thereof and spaced from the main yarn feeding station 16 a suitable distance inthe direction of needle rotation, is a flat yarn restraining element 20 (FIGS. 3, 4, 5). The restraining element 20 is formed with a curved tapering finger 211a, which is disposed adjacent the periphery of the cap 14, and which has its distal end formed with an upwardly curved extension 2%. As will be more fully explained, the inner side 20c of the finger 20a is curved concavely so as to maintain at all times suflicient tension on a yarn looped around element 20 to prevent the formation of slack in the yarn.

A retractable yarn clamp 21 is provided to hold securely, against the upper surface of restraining element 2%, the various yarns extending from the yarn fingers of the main feeding station 16 (see FIG. 21). Yarn clamp 21 is pivotally mounted at its inner end to yarn clamp lever 22 by means of the shoulder screw 23 (FIG. 2). Lever 22, in turn, is pivotally mounted by shoulder screw 24011 an embossment 14b formed on the upstanding hub 14a of the transfer cap 14. The distal end 22a of lever 22 is positioned directly below the protruding end of piston 25 of air cylinder 26 (FIG. 1). When compressed air is introduced into the cylinder 26, the piston .25 is forced downward, whereby its protruding end forces the distal end 22a of lever 22 downward to actuate that lever to raise the yarn clamp 21. A tension spring 30 having one end secured to an upstanding bracket 31 mounted on embossment 14b and having its other end affixed to lever 22 urges the distal end 22a of lever 22 upwardly into constant contact with the protruding end of piston 25. Thus, spring 30 acts to urge clamp 21 into contact with the upper surface of yarn restraining element 20. By means of the mechanical clamp 21, it is possibleto maintain a positive holding action upon the yarns extending and fed from the main feeding station 16, and thus ensure proper loop formation during knitting.

Mounted on the transfer cap 14, and spaced slightly above the restraining element 20, on opposite sides of the yarn clamp 21, are hollow hoods 32 and 33 (FIG. 3). FIGS. 4 and 5 are fragmentary views showing the relationship of restraining element 20 and hood 33. A vertical conduit 34- connects the hollow of hood 33 to a branch air line. 35 (FIG. 1). Branch air line 35 is connected at one end to main air line 36, and its opposite end 37 is open and disposed adjacent to the open end of a basketlike receptacle 38. As will be readily noted, main air line 36 is also connected to cylinder 26.

The yarn cutter for the main yarn feed 16 comprises a knife 40 affixed to an elongated rod 41 which, in turn, is telescopically mounted within the hollow arm 42 of the bracket 43 (FIGS. 2, 8). A shaft 44 is affixed to bracket 43 and journalled for rotary movement in the spaced embossments 33a and 33b formed on hood 33 (FIGS. 4, 9). It is to be noted that the embossments 33a, 33b of hood 33 are disposed so as to support bracket 43 substantially radially of conduit 34, with knife 40 disposed immediately above the periphery of annulus 13 (FIG. 3). A collar 45 is mounted telescopically of shaft 44 (FIG. 9), and is securely afi'lxed thereto by a set screw 46. A tension spring 47, having one end secured to set screw 46 and its opposite end secured to screw 48 mounted on the transfer cap 14, urges shaft 44 in a clockwise direction, as seen in FIG. 8, thereby urging knife 40 into contact with the periphery of annulus 13. As will be explained in more detail, the pressure between the cutting edge of knife 40 and the upper surface of annulus 13, effected by spring 47, causes the severance of yarn Y, extending from needle N, as the yarn is delivered to knife 40 FIG. 8).

The rod 41 of knife 411 has disposed in its upper end a transverse slot through which is passed a spring wire 49. Spring wire 49 is secured to bracket 43 by any suitable means, such as a screw 49a, and thus serves to retain rod 41 within arm 42, thereby ensuring that cutter 40 is at all times properly positioned with respect to the periphery of annulus 13. Because the teeth of annulus 13 may not always be in perfect horizontal alignment, it is preferred that knife 46 be given sufiicient play or flexibility to ensure that it is at all times in proper yarn cutting relation with the annulus teeth. In order to give knife 40 sufficient flexibility forthis purpose, the slot in the upper end of rod 41 may be slightly elongated or widened, thereby permitting rod 41 and knife 4-0 to pivot to a small degree about the spring wire 49. It is to be noted that the annulus 13 serves as a delivery device for carrying yarn from the main yarn feeding station 16 to the yarn cutter 40. More particularly, upon the dropping of the yarn finger 16a to active position, for the introduction of yarn Y to the needles, the yarn is drawn down by the first needle N to which it is fed and is incidentally caught between adjacent teeth of the annulus 13. As the needles and annulus continue to rotate, the yarn is dragged by the teeth of annulus 13 to the knife 40, as shown in FIGS. 8, 9, 21, 22, 23, whereupon the yarn is sever-ed by the knife close to the needles to leave a short, inconspicuous end of yarn trailing from the fabric. Similarly, when the yarn finger 16a is retracted to inactive position, so as to withdraw its yarn from the needles, the yarn is drawn down by the last needle N to which it is fed and at the same time is caught between a pair of adjacent teeth of the annulus 13. Upon cont1nued rotation of the needles and the annulus (FIGS. 25, 26), the yarn again is dragged by the teeth of the annulus 13 to the knife 40 for severance close to the fabric.

When the yarn finger 16a is retracted to remove the yarn Y from the needles, the yarn-as it is dragged by the teeth of the annulus 13 from finger 16a toward the knife 4t)is pulled between clamp 21 and the contiguous upper surface of restraining element 20, and securely held therebetween (FIG. 26). In order to facilitate this insertion of the yarn between clamp 21 and restraining element 20, while those parts are in yarn holding contact, the lower edge of the side of clamp 21 facing the main yarn feed 16 is bevelled at 50 (see FIG. ll). It is to be noted that the lower edge of the opposite side of clamp 21 is not bevelled. This construction permits the insertion of the yarn Y between clamp 21 and restraining element 20 as the yarn is carried from the yarn feeding station 16, while at the same time renders it difficult for the yarn to be pulled from between clamp 21 and element 20 in a direction toward the main yarn feed 16. Thus, while yarn Y is readily inserted under clamp 21 as it is dragged by the teeth of the annulus 13 toward the cutter 40, the yarn also is securely retained by clamp 21 after it has been inserted under that clamp and severed by knife 40. As will be readily understood from FIG. 26, the positive clamping action of clamp 21 upon the yarn Y extending from finger 16a serves to hold that portion of the yarn under sufficient tension to render it slackfree.

The ready insertion of yarn Y under clamp 21, as the yarn moves toward the cutter 40, is also facilitated by pivoting clamp 21 at its inner end to lever 22. By this arrangement, less clamping pressure is exerted, due to the action of spring 30, by the outer portion of clamp 21 on restraining element than that which is exerted by the inner portion thereof. As will be readily understood, the amount of pressure thus exerted by clamp 21 on r straining element 29 increases progressively from the outer end of the clamp toward the inner end thereof.

As the outgoing or retracted yarn is pulled by the teeth of the annulus 13 under the clamp 21, the segment of the yarn extending between the clamp and the teeth of the annulus is tensioned by the frictional drag exerted upon the yarn by the clamp and the contiguous surface of the restraining element. Thus, the outgoing yarn will arrive at knife in a slack-free condition to ensure proper severing thereof.

Upon the lowering of yarn feeding finger 16a to active position to introduce yarn Y to the needles (FIG. 21), the yarnas it is dragged by the teeth of the annulus 13 toward the knife 4tlis pulled under the restraining element 20 (FIGS. 22, 23), and the yarn thus is looped around that element. The up-turned extension 20b of element 20 serves to facilitate the movement of the yarn under the element. As the newly inserted yarn is dragged by the teeth of the annulus 13 to the knife 40, it is at all times maintained under tension, i.e. slack-free, by the curved portion 290 ofthe yarn restraining element 20 and the positive clamping action of clamp 21. Thus the newly inserted yarn arrives at knife 40 under suflicient tension to ensure proper severing thereof. The severing of the ingoin" yarn Y by the knife 40 produces a loose yarn end looped about the restraining element 20 which is thereafter removed by suction through conduit 34 (see FIG. 4) as will be explained more fully hereinafter.

It is necessary that knife 4% be incontact with the upper surface of annulus 13 for only a relatively brief period of time to sever yarns introduced to or removed from the needles. At all other times, to save wear on the knife 4t) caused by its rubbing contact with the rotating annulus 13, it is desirable that knife 40 be retracted from the upper surface of annulus 13, as shown in FIG.

10. Means for raising and lowering knife 40 in relation to annulus 13 is provided through the movement of horizontal bar 51 which is connected at one end to a second arm 52 of bracket 43 by means of a vertical rod 53 (FIGS. 1, 2). Vertical movement of rod 53 results in vertical movement of knife 49 toward and away from the annulus 13 about shaft 44 as a pivot.

The horizontal bar 51 has its end remote from rod 53 afiixed to the conventional shear lever 54 of the Scott 8: Williams Model KN machine. pivoted about fixed shaft 55 in the customary manner and is actuated by means of its conventional thrust bar 56 which, in turn, is actuated in the usual manner by the main pattern drum 57 and its associated earns 58, as is well understood in the art. Thus, when a cam 58 raises the thrust bar 56 upon a rotative shog of drum 57, such movement is transmitted through shear lever 54 and horizontal bar 51 to depress rod 53 and thereby depress knife 4t) into contact with the upper surface of annulus 13. When thrust bar 56 is retracted upon subsequent rotative shog of drum 57, such movement is transmitted pivoted at 64 on an upstanding stationary bracket 65' secured to the frame of the knitting machine. The distal Shear lever 54 is end of lever 63 has mounted therein a threaded bolt 66, the lower end of which is in contact with the upwardly protruding portion of the piston 67 of air valve 69. Air valve 69 is disposed in air supply conduit 71 and is connected to the main air line 36 by means of conduit 70. Thus, when thrust bar 61 is raised by a cam 60, it acts, through bracket 62 and lever 63, to depress bolts 66 and hence piston 67 to thereby permit compressed air to pass from air supply conduit 71 through valve 6? and conduit 7r) to the main air line 36, and thence to both branch air line 35 and the cylinder 26. As compressed air passes through branch line 35, it has the effect of an aspirator upon conduit 34, thus creating a suction therein. As will be readily understood, while the compressed air passing through branch air line 35 creates a suction in conduit 34-, the compressed air passing through main air line 36 in the other direction, to cylinder 26, depresses piston 25, thus raising yarn clamp 21 to release the yarns held thereby. As a result, the loose yarn end looped about restraining element 26 is sucked up conduit 34 and through branch air line 35, and deposited in the receptacle 38.

The yarn handling mechanism for the auxiliary yarn feed 17 will next be described. Mounted upon and slightly above the transfer cap 14, and spaced from the auxiliary yarn feeding station 17 a suitable distance in the direction of needle rotation, is a second fiat yarn restraining element (FIGS. 3, 6, 7). :The restraining element 86 is formed with a curved tapering finger 80a, which is disposed adjacent the periphery of the transfer cap 14, and which has its distal end formed with an upwardly curved extension 80b. The inner side sac of the linger t a is. curved concavely so as to maintain at all times sufficient tension on a yarn looped around the restraining element as to prevent the formation of slack in the yarn.

A retractable yarn clamp 81 is provided to hold securely against the upper surface of restraining element 80 the various yarns extending from the yarn fingers of the auxiliary feeding station 17 (see FIG. 21). Yarn clamp 81 is pivotally mounted at its inner end to yarn clamp lever $2 by means of the shoulder screw 83 (FIG. 1). Lever 82, in turn, is pivotally mounted by shoulder screw'84 on an upstanding embossment 85 afiixed to hood 86 (see FIGS. 6, 7). The distal end 82a of lever 82,-as best shown in FIG. 1, is bent to underride lever 22 so that the downward movement of the distal end of lever 22, as actuated by piston 25, causes the distal end 82a of lever 82 to be simultaneously lowered with consequent raising of yarn clamp 81, thus releasing the yarns held thereby. A tension spring 87, having one end secured to an upstanding stud -90 disposed on top of embossment 85 and having its other end affixed to lever 32 (FIG 1), urges the distal end of lever 82 upwardly into constant contact with the underside of lever 22. Thus, spring 87 acts to urge clamp 81 into yarn holding contact with the upper surface of the yarn restraining element 80.

The hollow hood 86 is mounted on the transfer cap 14 so as to be spaced slightly above the restraining element 80 and so as to be disposed adjacent the yarn clamp 81 (FIG. 3). FIGS. 6 and 7 are fragmentary views illustrating the relationship between hood 86 andrestraining ele ment A verticalconduit 91 connects the hollow of hood $6 to a branch air line 32 (FIG. 1). Branch air line 92 is, connected to one end to main air line 36, and its opposite end 93 is open and disposed adjacent to the opening of receptacle 38.. r

Referring to FIGS. 6 and 7, it will be seen that restraining element 86 is formed with a dependent portion 80d, and that hood 86 has afiixed thereto, adjacent the periphery of the transfer cap 14, a shield 94. The purpose of these elements will be explained hereinafter in detail.

In the conventional Scott &.Williams Model KN machine having the usual two feed attachment, the yarns from the auxiliary feeding station are inserted and withdrawn at a level somewhat above the sinkers (not shown). This condition is brought about by the fact that the yarn feeding fingers of the auxiliary feeding station 17 are disposed at a level slightly above that of the fingers of the main feeding station 16. Thus, it is necessary for the needles which first take a yarn from one of the fingers of the auxiliary feeding station to be raised slightly higher than normal, above the sinker level. The needles must similarly be raised immediately prior to the withdrawal of a yarn fed at the auxiliary feeding station. Except during yarn insertion and withdrawal, during which times about successive needles are raised above the sinker level, the yarns from the auxiliary feeding station are fed with the needles at the usual knitting level.

Thus, a different type of yarn cutting device preferably is utilized for the second yarn feed 17 of a Scott & Williams Model KN machine with a two feed attachment. In such machine, the toothed annulus 15 is not effective for delivering the newly inserted or withdrawn yarns to the yarn cutter. The yarn cutting device for yarns fed from the auxiliary feeding station 17 is best disclosed in FIGS. 1, 12 and 13. This device consists of a rotary toothed cutting wheel which is disposed in yarn shearing relation with a cutting blade 96 so as to sever yarn which passes therebetween.

The yarns from the auxiliary yarn feed 17 which are to be severed by the cutting wheel 95 and the cutting blade 96 are delivered thereto by the needles. More particularly, upon the dropping of the yarn finger 17a to active position, for the introduction of yarn Y to the needles, the yarn is taken by the first needle N to which it is fed (as well as the succeeding needles) and is carried by needle N around the needle circle to the cutting wheel 95 (see FIGS. 21, 22, 23). At thispoint, the yarn is still above the level of the sinkers. As the yarn reaches cuttingnwheel 95, it is caught in the teeth thereof (FIG. 12) and, due to the rotation of cutting wheel 95, the yarn is delivered or pulled down by the wheel 95 to the cutting blade 96 (FIG. 13) whereupon the yarn is severed close to the needle circle. As a result, only a small inconspicuous end of yarn trails from the knitted fabric. Similarly, when the yarn finger 17a is retracted to inactive position, so as to withdraw the yarn from the needles, the yarn is carried by the last needle N to which it is fed to the cutting wheel 95, whereupon the yarn is caught by the teeth of the wheel and carried down to the cutting blade 96 for severance close to the needle circle (FIGS. 12, 13, 24, 25, 26).

The cutting blade 96 is integrally formed on a sleeve 97 telescopically mounted upon upstanding stud 93 afiixed in transfer cap 14 (FIGS. 12, 13). A collar 100 is aflixed to the upper end of stud 98 by means of a set screw 1111. A coil spring 1112 having its upper end bent about set screw 101 serves to urge cuttingblade 96 into shearing relation with cutting wheel 95, thereby ensuring proper severance of the yarns delivered to the cutting wheel (FIGS. 1, 12,13).

The drive means for cutting wheel 95 is best shown in FIGS. 1, l4 and 15. Cutting wheel 95 is affixed to a horizontal shaft 103 which, in turn, is geared to a vertical shaft 104. Shafts 163 and 104 are supported in a fixed bracket 105. Shaft 1114 is geared to ahorizontal shaft 1116 supported by fixed bearing 107 and vertically slidable bearing 1118. Bearing 108 is slidably mounted in the inverted U-shaped portion 110 of bracket 111 which is secured by screws 112 to the cross bar 113 of the 'machine. Shaft 106 is driven by conventional gear 114- through circular rack 115 and pinion 116. A sleeve 117 transmits power from gear 114 to the circular rack 115. A pin 120 extends from slidable bearing 1% through a slot 121 in the inverted U-shaped portion 110 of the bracket 111, said pin 120 having afiixed to its distal end the upper end of a tension spring 122. The opposite end of spring 122 is affixed to the distal end of a screw or pin 123 affixed to the end of a lever 124. Thus, pinion 8 116 is urged downwardly by the spring 122 into teeth meshing contact with the circular. rack 115.

Since the rotation of cutting wheel 95 is required for only a very brief period, just after yarns are introduced to or removed from the needles, it is preferred that cutting wheel 95 be rendered inactive at all other times. This is accomplished by raising pinion 116 to disengage it from the circular rack 115, as shown in FIG. 14, at all times except when the cutting of yarn is required following a yarn change. The upward movement of pinion 116 is effected through a threaded rod or bolt which is vertically disposed in the distal end of lever 124 with its upper end in contact with the lower surface of slidable bearing 108. Lever 124 is affixed at its proximal end to a right angled bracket 126, said bracket having one end pivoted about stationary shaft 55 and having its other end afiixed to the shear lever 54 (FIG. 14). When thrust bar 56 is actuated upward by one of the cams 58, to depress cutter 40 to yarn cutting position, it simultaneously, through shear lever 54, depresses bracket 126, lever 124 and bolt 125, whereby spring 122 pulls pinion 116 into meshing engagement with circular rack 115. When the cam 58 is removed from under thrust bar 56, by rotative shog of the drum 57, thrust bar 56 is retracted to raise knife 46, as previously explained, and at the same time, through shear lever 54, bracket 126, lever 124 and bolt 125, disengages pinion 116 from the circular rack 115. It will thus be seen that the cutting devices for each yarn feeding station are activated simultaneously for the cutting of newly inserted or removed yarns.

The lower edge of clamp 81 facing the auxiliary yarn feeding station 17 is bevelled in the same manner as clamp 21, as shown in FIG. 11. By reason of such bevelling, and by reason of the fact that clamp 81 is pivoted at its inner end to lever 82, each newly retracted yarn Yas it is pulled by the last needle N to which it is fed to cutting wheel 95is inserted between clamp 81 and the upper surface of restraining element 30 while the clamp is in yarn holding position (FIGS. 25, 26). For the reasons previously explained with respect to clamp 21, such construction of clamp 81 permits the ready insertion of yarn under the clamp, while ensuring that the yarns extending from feeding station 17 and held between the clamp and the restraining element 80 will be retained free of slack.

As the outgoing or retracted yarn is pulled by the needle N under the clamp 81, the segment of the yarn extending between the clamp and the needle is tensioned by the frictional drag exerted upon the yarn by the clamp and the contiguous surface of the restraining element. Thus, the outgoing yarn will arrive at cutting wheel 95 in a slack-free condition to ensure proper severing thereof.

Upon the lowering of yarn feeding finger 17a to active position to introduce yarn Y to the needles, the yarn, as it is pulled by the needle N toward the cutting wheel 95, is dragged under the restraining element 80, and the yarn thus looped around that element in the manner shown in FIGS. 22, 23. The up-turned extension 8012 of element 80 serves to .facilitate the movement of the yarn under that element as the yarn moves toward cutting wheel 95. As the newly inserted yarn is dragged by the needle N to the cutting Wheel 95, it is at all times maintained under tension, i.e. slack-free, by the curved portion 80c of the yarn restraining element 80 and the positive clamping 'action of clamp 81. Thus, the newly inserted yarn arrives at the cutting wheel 95under sufiicient tension to ensure proper severing thereof, such tension on the yarn being maintained, of-course, as the teeth of the cutting wheel deliver the yarn to the cutting blade 96. The severing of the yarn Y by the cutting wheel 95and cutting blade 96 produces a loose yarn end disposed about the restraining element 80, which is thereafter removed by suction created in the conduit 91 (FIG. 6).

The dependent portion-80d of restraining element 80 acts'as a barrier to prevent the passage of the loose yarn portion, cut from a newly inserted yarn Y, from under the restraining element 80 into contact with the needles. The shield 94 afiixed to hood 86 serves a similar purpose for the retracted yarns. Specifically, shield 94 prevents the cut end of the outgoing yarn, extending beyond clamp 81, from passing under hood 86 to the needles.

The loose or cut yarn portion, severed from an ingoing yarn by the cutting wheel 95 and the cutting blade 96, is removed to a point remote from the needle circle in a manner similar to that previously described with respect to. the severed yarn portions cut from yarns fed from the main yarn feed 16. Specifically, when lever 63 is actuated and valve 69 opened to permit compressed air to enter the main air line 36, compressed air passes through branch air line 92 and discharges through the open end 93 thereof into the receptacle 38. The passage of compressed air through branch air line '92 creates an aspirator effect with respect to conduit 91, creating a suction in that conduit and in the hollow of hood 86. As a result, when clamp 81 is retracted, the cut portion of yarn Y looped about restraining element 80 is sucked up through conduit 91 and passes through line 93 into the receptacle 38.

It is preferred in practice that the clamps 21 and 81 be raised simultaneously with the opening of air valve 69 and the creation of suction in conduits 34 and 91. This arrangement permits the cut yarn portions to be released by the yarn clamps for immediate removal by the suction in conduits 34 and 91. Of course, in normal practice a number of individual inactive yarns will extend from each yarn feeding station to its associated clamp. When the clamps are raised, it is necessary that means he provided to prevent these inactive yarns from being displaced from yarn clamping position upon their rest-raining elements. The suction created in conduits 34 and 91 and in the hollows of their associated hoods serves this purpose. .Such suction created in the hollows of the hoods acts to pull upon or tension the inactive yarns disposed under the clamps, and prevent-s their displacement when the clamps are raised to permit removal of the loose yarn portions to the receptacle 3%.

In practice, it is preferred that the yarn cutters 4t and95 be activated simultaneously for yarn cutting by the cams 58 of drum 57 immediately prior to the arrival of the yarns at the yarn cutting stations, and that said cutters be deactivated immediately after severance of the yarns.

FIGS. 16, 17 and 18 show a modified form of the yarn handling mechanism forthe main yarn feed 16. In this modification, the hoods 32, 33 have been dispensed with, and the conduit 34 is disposed immediately aboverestraining element 29, the open end of conduit 3 being spaced a slight distance above the upper surface of re straining element 20. All parts of the modification of FIGS. 16, 17 and 18 which correspond to parts shown in FIGS. 1 to inclusive have been designated by the same reference numeral with the addition of the prime sign. Since the hoods have been removed from the modi-' fication of FIGS. 16, 17 and 18, the bracket 4-3 and the knife 4%) are supported for rotary movement by an L-shaped bracket 13f mounted directly upon transfer cap 14, the shaft 44' of bracket 43 being supported in bracket 130 and held in place therein by mean of threaded pin 131 and set screw 132. if desired, a yarn guard 133 may be mounted on the outside of bracket 43 to ensure that yarn extending from the auxiliary yarn feeding station to the needles, following yarn retraction, does not become entangled with the cutter 46.

In FIGS. 19 and there is shown a modified for-m of the yarn handling mechanism forsthe auxiliary yarn feed 17. In this modification, the hood 86 has been dispensed with and the conduit 91 extends down toward the restraining element 80 so that its open end is disposed just slightly above the upper surface of said element. The parts of the modification of FIGS, 19 and 20 which correspond to parts disclosed in the embodiment of the invention of FIGS. 1 to 15 inclusive bear identical reference numerals with the addition of the prime sign.

Operation The operation of the yarn clamping and severing mechanism of this invention is illustrated diagrammatically in FIGS. 21 to 26 inclusive. In FIG. 21 the yarn finger 16a of the main yarn feeding station 16 has been lowered to active position, and yarn Y is being engaged by the first needle N to which it is fed. The yarn Y extends from the yarn finger 16a over the top of yarn restraining element 20 and under yarn clamp 21 and hoods 32 and 33. Clamp 21 is in contact with the upper surface of yarn restraining element 26 and thus holds yarn Y lack-free in a fixed position above the transfer cap 14. Similarly, yarn finger 17a in FIG, 21 has been lowered and needle N engages the newly inserted yarn Y. Yarn Y is clamped slack-free between clamp 81 and the upper surface of restraining element St and passes under hood 86.

As the first needle N to which the yarn Y is fed is retracted, the yarn is pulled down between two adjacent teeth of the annulus 13. As shown in FIGS. 22 and 23, yarn Y is dragged by the teeth of the annulus 13 around the needle circle to cutter 40 where the yarn is severed. As the yarn Y is delivered to thecutter 40, it is pulled under the yarn restraining element 20 and thus looped around the. curved edge 26c thereof. Due to the curvature of the edge 20C and the positive clamping action of clamp 21, t-he yarn Y is maintained slack-free as it is delivered to the cutter 49. Following the cutting of the yarn Y by the cutter 4t clamp 21 is retracted and suction is created in conduit 34 to remove the cut yarn portion from within the needle circle.

Meanwhile, the yarn Y is carried by the needle N about the needle circle to the cutting Wheel 95, whereupon the teeth of the cutting wheel deliver the yarn to the cutting blade 96, thereby severing it. As yarn Y is pulled in the direction of the cutting wheel 95, it is dragged below restraining element 30 and looped slackfree around the curved edge 86c thereof, as shown in FIGS. 22 and 23. After the yarn Y has been severed, clamp 81 is retracted and the loose yarn portion is removed from Within the needle circle by suction created in conduit 91.

In FIGS. 24, 25 and 26 yarn retraction i diagrammatically illustrated. In FIG. 24 the yarn fingers 16a and 17a, shown in active :position feeding yarns Y, Y to the needles, are about to be retracted. In FIG. 25 the yarn fingers have been raised to inactive position, and the yarns Y and Y withdrawn from the needles. The last needle to which each yarn is fed, is designated N and N, respectively. As the yarns Y and Y proceed in the direction of the yarn cutters, they are dragged under the yarn clamps 21 and 83., their insertion under those clamps being facilitated by the bevelling previously described and by the pivoting of the clamps at their inner ends to their respective clamp levers. In FIG. 26, the yarns Y and Y have been delivered to their respective cutters and are in the process of being severed and, as will-bereadily noted, the yarns have been fully inserted under theirrespective yarn clamps.

It will be readily understood by those skilled in the art that whenever a yarn change occurs at a yarn feeding station, the ingoing yarn will be inserted shortly before the outgoing yarn is retracted. Thus, two yarn feeding fingers of the yarn feeding station will simultaneously feed their respective yarns for a brief period to the same needles to provide a short yarn lap. Thereupon, the outgoing yarn finger is retracted to remove the outgoing yarn from the needles. Thus, following a yarn change, the ingoing and outgoing yarns from the yarn feeding stations will be carried simultaneously to the yarn cutters. In the manner previously described, the yarn and outgoing yarns in quick succession, after which the yarn cutters will be deactivated. Hence, as will be readily understood, while the ingo-ing yarn from a yarn feeding station is'bein-g delivered to its yarn cutter and, at the same time, is being looped around the yarn restraining element, as shown in FIGS, 21-23, the outgoing yarn is also being delivered to the yarn cutter and, at the same time, is being dragged over the restraining element and under the yarn clamp, as shown in FIGS. 2426.

It also will be understood by those skilled in the art that whenever a yarn change occurs there always will be formed within the needle circle a severed yarn portion from each ingoing yarn. Thus, every time there is a yarn change the clampsand suction means can be simultaneously activated, following cutting of the yarns, to removie the severed yarn portions. However}, in actual practice it is preferred to accumulate the severed yarn portions under the clamps, and to activate the clamps and suction means only once during the knitting of a stocking for simultaneous removal of all severed yarn portions which have accumulated. In the knitting of ladies hosiery, it is preferredthat activation of the clamps and suction means for removal of the severed yarn portions take place at the stocking transfer, where possible disturbance of the yarns will be reduced to a minimum. It will be understood, of course, that yarn removal may occur whenever desired during knitting, and that it may be efiected as often as desired during the knitting of each stocking. I

It is to be understood that while this invention has been illustrated and described specifically with respect to a Scott & Williams Model KN knitting machine with a two feed attachment for ladies hosiery, the invention is readily adaptable to all types of circular knitting machines for all types of hosiery. With many such machines currently in use, such as the Scott & Williams Model KN-II machine and the Reading-Booton twin feed ladies hosiery machines, where the yarns from all feeds are introduced to the needles at the sinker lever, it is possible to use, for the yarns fed from the subsequent feeding stations, cutters like those used for severing the yarns fed from the first yarn feeding station. In such machines, a cutter such as that indicated by the numeral 40 in the drawings would be preferred for use with each feed-. ing station, and the cutting wheel 95 and the cutting blade 96 would be dispensed with. With such arrangement, the teeth of the annulus 13 would serve as the yarn conveyor for delivering all of the yarns to be severed to the proper yarn cutters. Thus, the invention hereof is not to be considered as being limited to the details of cutters will be activated so as to cut both the ingoing 12 construction and arrangement shown in the drawings since, as will be readily understood by those skilled in the art, considerable modifications may be made in the inventionas disclosed and described without departing from the scope of the appended claim.

Having thus described my invention, I claim:

In a circular knitting machine having a plurality of independent needles arranged in a circle, a transfer dial cap disposed within the needle circle and at least two yarn feeding stations, yarn trimming means comprising:

(a) a retractable yarn severing element mounted on v the dial cap proximate the needle circle,

(b) means for moving said retractable severing element into yarn shearing relation with a cooperating yarn severing element.

(c) a fixed yarn severing element mounted on the dial cap proximate the needle circle and angularly spaced from said retractable yarn severing element,

(d) a rotatable horizontal axis, toothed wheel disposed in yarn shearing relation with the fixed yarn severing element,

(e) said wheel being positioned on the dial cap to intercept in its toothed periphery, during a yarn change, the trailing portion of a newly inserted yarn and also a withdrawn yarn,

(f) means for periodically rotating the wheel to deliver the intercepted yarns to the fixed severing element and a (g) control means for periodically and simultaneously moving the retractable yarn element and rotating the rotatable toothed wheel to sever yarn.

References Cited by the Examiner UNITED STATES PATENTS 634,510 10/99 Sullivan 66140 1,115,128 10/14 Swinglehurst 66140 X 1,400,180 12/21 Pigeon 66145 1,727,783 9/29 Pulster 66140 2,146,647 2/39 Page 6642 2,325,023 7/43 Allred 66l68 X 2,525,704 10/50 Miller 66-42 2,824,436 2/58 Stack et a1. 66140 2,908,154 10/59 Butler 66140 2,952,148 9/60 Rather 66-140 3,055,199 9/62 Stack 66140 3,097,512 7/63 Moyer 66140 FOREIGN PATENTS 593,152 5/59 Italy.

RUSSELL C. MADER, Primary Examiner.

Images