US3813900A

US3813900A - Pneumatic yarn feeder device for knitting machines

Info

Publication number: US3813900A
Application number: US00179484A
Authority: US
Inventors: W Cook; J Baker
Original assignee: Scott and Williams Inc
Current assignee: Scott and Williams Inc
Priority date: 1971-09-10
Filing date: 1971-09-10
Publication date: 1974-06-04
Anticipated expiration: 1991-06-04

Abstract

A yarn feeding device comprising a plurality of concentric and axially aligned tubes forming a compact, slender structure adapted to be employed in a confined yarn feed station of a knitting machine. The feeder includes the features of pneumatic yarn feed control, reciprocation of the feeder along its axis towards and away from the needles to provide positive yarn feeding and to provide room for the subsequent introduction of other yarn feeders in the same area, and a space saving axially actuated yarn clamp for introducing and terminating yarn feed.

Description

United States Patent [191 Cook et al.

[ 1 June 4, 1974 PNEUMATIC YARN FEEDER DEVICE FOR KNITTING MACHINES [75] Inventors: Willard P. Cook; J. Howard Baker,

both of Drexel, NC.

[52] [1.5. CI 66/125 R, 66/131, 226/97 [51] Int. Cl D04b 15/48 [58] Field of Search 66/125 R, 131; 226/7, 97;

139/127 P; 28/1 SM, 1.4

[56] References Cited UNITED STATES PATENTS 2,928,121 3/1960 Plumbo 28]] SM X 3.249.127 5/1966 Payne; 139/127 P 3,511,064 5/1970 Major et al. 66/125 R FOREIGN PATENTS OR APPLICATIONS 1,069,813 11/1959 Germany 66/125 R 5 a" M EFL] Great Britain 66/125 R Italy 66/125 R Primary Examiner-Robert R. Mackey Attorney, Agent, or Firm-McNenny, Farrington, Pearne & Gordon 5 7] ABSTRACT A yarn feeding device comprising a plurality of concentric and axially aligned tubes forming a compact, slender structure adapted to be employed in a confined yarn feed station of a knitting machine. The feeder includes the features of pneumatic yarn feed control, reciprocation of the feeder along its axis towards and away from the needles to provide positive yarn feeding and to provide room for the subsequent introduction of other yarn feeders in the same area, and a space saving axially actuated yarn clamp for introducing and terminating yarn feed.

13 Claims, 7 Drawing Figures PNEUMATIC YARN FEEDER DEVICE FOR KNITTING MACHINES BACKGROUND OF THE INVENTION This invention relates generally to knitting and more specifically to the feeding of yarn to the knitting instrumentalities in weft knitting machines.

More specifically, this invention will be described with respect to circular knitting machines of the latch needle type, although it is understood according to the broader aspects of this invention that it is applicable to weft knitting machines of other types.

At a knitting station, by which is meant the location in the machine where the knitting instrumentalities receive yarn from a source and by a suitable mechanism are caused to move and draw the yarn into loops or stitches, there is relatively little problem with feeding of yarn during the knitting of fabrics in which the yarn is fed at the knitting station continuously and without interruption or alteration with other yarns. In such case, relatively simple arrangements, such as fixed guides, may be employed to direct the yarn at the proper location with respect to the knitting instrumentalities so that the desired stitches are formed. However, with the knitting of many products, and more specifically the knitting of hosiery, on both fine guage jersey and rib knit, whether on single or double bed machines, it is necessary to be able to feed a plurality of different yarns at a single knitting station and to be able to rapidly and precisely begin the feeding of and interrupt the feeding of such yarns in a precise sequence to insure sufficient overlap of the yarns as to provide a coursewise continuous stitch structure without the overlap being so great as to provide an undesirable visible appearance in the fabric structure. In addition, it is necessary that the yarns be introduced at specific location since the stitch structure is determined in many cases by the specific relationship between the yarn and the knitting instrumentalities at the knitting station to determine whether or not the instrumentalities receive the yarn in their hooks. For this reason, it is necessary that the guide feeding a yarn be given a very precise position withrespect to the needle level in a vertical dimension, and this in turn means that there is a need for a plurality of yarn guides or feed fingers, one for each different yarn, which may be fed during the cycle of operation, and these must therefore be spread out horizontally or circumferentially about the periphery of the needle circle at the knitting station. As a result of this spreading out, some yarns may be fed at different points along the periphery, thus compromising the optimum position for proper stitch control and formation.

Another problem that is encountered with a yarn feed is the necessity of introducing a new yarn into the needles so that the hooks of the needles may begin to draw the yarn from the supply before the yarn has been knitted into the fabric in such a way that the continued rotation of the needle cylinder will in and of itself draw the yarn from the supply. Still another and more difficult problem is the combination, When the yarn is withdrawn, of severing the yarn end and clamping and otherwise retaining control over the yarn end as it comes from the supply after it has been severed from the fabric already knit. Still another problem is to control the ends of the yarn still in the fabric after it has been severed from the supply either to insure positively that the end will be knit in to leave no exposed free end or else to control the free end so that it is not accidentally knit in in an undesirable fashion, which could leave a defect in the finished article.

PRIOR ART Heretofore, there have been two general types of systems used on hosiery machines, depending upon the basic type of machine. On single cylinder machines, which almost universally include a dial, and may be either of the fine guage type in which the dial contains jacks for holding loops used in the formation of turned welts or coarser guage machines in which the dial includes latch or compound needle members and is suitable for knitting rib fabrics, it has been customary to mount the yarn clamping and cutting mechanism on the dial inside the needle circle and feed the yarn by means of fingers which may be raised and lowered and extend on the outside of the needle circle. Yarns being fed are introduced by lowering the finger into an active position and yarns are taken out of operation by raising the yarns to an inactive position where the needles are unable to take the yarn. The introduction of the yarn is easily effected because the inactive yarn extends from the supply to the inactive yarn finger end, which hasan eye or guide on it, to the clamping point on the inside of the needle circle, and when that finger is lowered, the yarn then extends down to a point where the needles can intercept the yarn when the yarn finger reaches the active position. This results in the necessity of'severing the clamped portion of the yarn extending from the needle circle inward to the clamp on the dial. Likewise, when the yarn is removed from operation. the finger is moved up to an inactive position and a suitable cutting mechanism is brought into operation to sever the portion that is now clamped on the clamping mechanism from the fabric from which the yarn extends. This has resulted in a great deal of development aimed at shortening the length of the cut ends by various mechanisms. As a result of this, every time a yarn is taken out of operation and later reintroduced, there is a waste portion which has been cut at both ends, being cut the first time when the yarn is taken out of operation from the end in the fabric and the second time when the yarn is reintroduced and the clamped portion must be severed from the more recently knit portions of the yarn. It is necessary to remove this waste portion of yarn from the clamping mechanism and this requires extra mechanism for handling the removal and disposal of this waste. ln addition, because the yarn is cut within the needle circle, the end extends inwardly and free ends will remain projecting loosely from the finished fabric.

On other types of machines, such as double cylinder machines where theabove-described mechanism cannot be used, the yarn feeding, cutting and clamping mechanisms are mounted entirely on the outside of the needle cylinder. When this is done, the removal of the yarn from knitting requires that it be very carefully and sequentially clamped and then cut so that the end from the supply may be held in place, and when reintroduced, it must be done with a special mechanical motion that actually moves the free end into the path of the open hooks of the needles so that they may take and begin to knit the free end of yarn. Although this type of yarn feeding mechanism does not have several of the disadvantages of the preceding type, in that there tion and adjustment to perform in the proper manner.

There have been prior attempts to provide a yarn feeder utilizing compressed air to intermittently introduce and direct yarn to the needles. Examples of such attempts are described in the following foreign patents: Great Britain 926,857; Germany 1,069,813; and Italy 597,024.

SUMMARY OF THE INVENTION A yarn feeder device as provided by the invention is adapted to be used with generally all types of weft knitting machines and is particularly useful in circular machines. It may be wholly mounted outside of the needle circle so as to provide advatnages in its mode of operation and in accessibility. The yarn feeder device or gun feeds yarn with a blast of air or other pressurized fluid directed at the needles. The feeder has a tubular structure which requires a minimum of space particularly at the needles owing to its configuration and its features of axial reciprocation and axial yarn feed actuation.

Air or other fluid directed axially out of the tubular feeder creates a vacuum to draw yarn from a central feeder tube and positively guides the yarn to the needles without requiring delicate mechanical supports in the area of the needles. Further, air may be employed to insure that the trailing end of a terminated yarn be positively blown into the needles and be knit into the fabric.

The yarn feeder device is actuated by suitable controls to extend and retract axially to position a yarn outlet or guideway sufficiently close to the needles for reliable feeding and to retract the outlet to allow other feeding devices to subsequently occupy the same or nearly the same feeding location for improved stitch control.

Associated with the feature of axial reciprocation of the yarn guideway is a yarn brake or clamp actuated by axial motion of the feeder. Yarn is, preferably, severed by clamping it at a desired time and allowing it to sever or break at the clamping surfaces as a preceding portion of the yarn is carried away from the feeder by the needles. The clamping action occurs simultaneously with reciprocation of the feeder device and, consequently, requires no additional control input other than that provided to reciprocate the feeder. Yarn is severed close to the needles so that only a short end portion of yarn need be knit after the yarn is terminated. No waste lengths of yarn are produced which otherwise would require disposal and periodic maintenance. The device is particularlysuited for feeding special yarns which are difficult to handle such as alginate yarn.

The yarn feeder, in its preferred form, has a modular construction so that it may be provided as an attachment for existing machines and so that it may be easily incorporated into new designs. Other than suitable mounting bracketry, the device requires only two inputs, both easily made through flexible connections, to be installed on a typical knitting machine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the yarn feeder device of the invention mounted on a knitting machine, the latter being shown somewhat schematically.

FIG. 2 is a plan view of the yarn feeder device.

FIG. 3 is a side elevational view of the yarn feeder device with certain parts broken away for the purposes of description.

FIG. 4 is a cross-sectional view, on a somewhat enlarged scale, of the front or forward portion of the yarn feeder device showing details of the yarn clamping apparatus.

FIG. 5 is a cross-sectional view, on a somewhat enlarged scale, of a central portion of the yarn feeder device illustrating details of a fluid circuit.

FIG. 6 is a cross-sectional view taken along the lines 6-6 of FIG. 4.

FIG. 7 is a cross-sectional view of the yarn feeder device taken along lines 77 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT There is shown in the Figures a yarn feeder device 10 having an elongated tubular structure comprising a number of telescoped tubes which, from their center outwards, function to carry yarn, provide yarn clamping, conduct pressurized fluid for yarn feed, and provide bearing surfaces for axial reciprocation of the device.

In FIG. I, the feeder 10 is shown mounted on a frame segment 11 of a typical knitting machine such as a circular Komet machine. The feeder 10 is bolted to the machine segment 11 with an adapter bracket 12 which enables the feeder 10 to be adjustably positioned with respect to the hooks, designated 13, of the knitting instrumentalities or needles 14 carried in the upper and lower needle cylinders or beds, designated 16 and 17. The bracket 12 and an associated bolt 15 permit both vertical and horizontal adjustment of a forward end 21 of the feeder 10 with respect to the needles 14 so that the forward end 21 of the feeder may be set in an optimum position. The feeder 10 is preferably mounted parallel to a plane radial to the'needle cylinders 16 and 17.

Yarn or thread 19 is received from a supply (not shown) and is guided to the forward end or tip 21 of the feeder 10 adjacent the needle hooks 13 by a longitudinally extending central yarn feeder tube 22. Feeding of the yarn 19 is controlled by the yarn feeder 10 in response to operation of a Bowden control cable assembly 26 and pressurized fluid supplied to the feeder 10 at a tubular fitting 27. The functions of the cable as sembly 26 and pressurized fluid admitted to the fitting 27 are explained below following a description of relatedstructure of the feeder 10.

A mounting block 31 is stationarily fixed to the adapter bracket 12 at a desired angle from the horizontal when the bolt 15, threaded into the block 3i, is tightened. As viewed from above in FIG. 2, the block 31 is L-shaped. A shorter side or leg 32 of the block 31 is slotted at 33 to admit a cable 34 of the cable assembly 26. Referring to FIG. 3, the slot 33 extends across the width of the leg 32 and down into a bore 36 wherein an outermost circular guide tube 37 of the feeder 10 is rigidly clamped when the bolt is tightened. An inner bore 38 of the guide tube 37 provides a linear bearing surface for axial reciprocation of a slider tube 39 therein. The slider tube 39 supports, at one end, a control yoke or block 41 and at an opposite end supports an extension tube 42.

The control yoke 41 is a generally flat, rectangular block having a central notch 43 separating the lower portion of the block into two

legs

44 and 45. Referring particularly to FIG. 5, the left leg 44 of the yoke 41 is provided with a circular bore 47 running lengthwise in the block 41. The lower portion of the left leg 44 may be formed with a slot (not shown) up to the bore 47 and be provided with screws (not shown) to close in the slot and thereby clamp the bore 47 tightly around the slider tube 39 so that the control yoke 41 reciprocates with the slider tube. Alternatively, the slider tube 39 and the bore 47 may be dimensioned to provide a press fit therebetween in order that the yoke 41 is securely positioned on the slider tube 39.

Referring particularly to FIG. 3, the rightward leg 45 of the yoke 41 has a threaded bore 48, extending lengthwise in the yoke 41, for reception of a threaded terminal or anchor 49 of the cable assembly 26. The cable terminal 49 is locked in a desired axial position on the yoke 41 by ajam nut 51. The cable 34 is secured in the fixed mounting block 31 by a pin which is permanently fixed to the end ofthe cable 34 and which lies in a hole in the block 31 communicating with the slot 33. As viewed in FIG. 2, the control yoke 41 is resiliently urged or biased to the right by a compression spring 53 seated on a pair of opposed bushings 54 and 55 abutting the control block 41 and the fixed mounting block 31 respectively. A set collar 52 is provided on the forward end of the slider tube 39 to determine the rightward position of the tube and to lock the extension tube 42 on the slider tube.

Referring particularly to FIG. 4, yarn 19 is guided longitudinally through the center of the feeder 10 in the interior, designated 60, of the circular yarn feeder tube 22 from a supply (not shown). At the forward or inner end of the yarn feeder tube 22, near the forward tip 21 of the feeder, yarn 19 is diverted radially out of the tube 22 through a radial slot 56 in the upper wall of the tube. Yarn is guided radially out of the yarn feeder tube 22 by a ramp 65 formed of filler material such as solder laid into the interior of the yarn feeder tube. The yarn 19 runs forward along an interior wall 57 of the forward extension 42 of th slider tube 39. The yarn 19 returns to the center or axis of the concentric feeder tubes along an inclined or conical surface 59 defining the entrance portion or end of a tubular yarn guideway 61.

Yarn 19 is clamped or braked between the inclined surface 59 of the yarn guideway 61 and a conical end 69 of a yarn snubber 71. The-yarn snubber or stop 71 may be formed of nylon or other material having similar hardness. The yarn snubber 71 is provided with an extension'72 of reduced diameter which is received in the adjacent end 73 of the yarn feeder tube 22 which end 73 is crimped down onto the extension 72 to permanently secure the snubber 71 therein.

As illustrated in HO. 5, compressed air or other pressurized fluid is conducted from the control yoke 41 to the forward end 21 of the feeder along an annular passage 81 outwardly bounded by an interior surface 76 of the slider tube 39. The inner boundary of the air passage 81 is defined by an outer surface 83 of an inner tubular case member 82. Compressed air, preferably, is directed from a supply (not shown) through the tubular fitting 27 threaded into a circular port or fluid passage 85 provided in the left leg 44 of the control yoke 41.

A cross-bore 87 extends perpendicularly through the port 85 for passage therethrough of the cable 34. A tubular bushing 88 is pressed in the bore 87 to prevent loss of pressurized fluid from the port 85 through the cross-bore 87. The cross-bore 87 and bushing 88 are smaller in diameter than the diameter of the port 85 so that the bushing 88 does not fully block the circular cross section of the port. The port 85 communicates with a hole 89 in the wall of the slider tube 39 which admits air or other fluid to the annular fluid passage 81.

An annular air passage 81 is formed by relieving or machining a portion of the wall of the inner tubular case member 82 to form a reduced diameter section defining the outer surface 83 and extending axially from the hole 89 in the slider tube 39 forward to a point adjacent the radial slot 56 inthe yarn feeder tube 22. The major diameter of the inner tubular case 82 is sufficiently large to seal against the

inner surfaces

76 and 57 of the slider tube 39 and extension 42. The inner air case is axially positioned in the slider tube 39 by a threaded nut 101 on the rightwardend of the case as viewed in HO. 5. The outer diameter of the inner end, designated 66, of the yarn guideway 61 and the inner diameter of the inner tubular air case 82 are dimensioned so that the guideway 61 is retained in the case 82 by a press fit. The outer diameter of the yarn tube 22 and inner diameter of the air case 82 are dimensioned to allow the yarn tube to freely reciprocate in the air case.

As shown in FIGS. 4 and 7, a radial slot 92 is cut through the upper wall of the case member 82 to allow the yarn 19 to pass out of the yarn feeder tube 22 around the snubber or yarn stop 71 and then return to the center of the feeder tubes and into the entrance end 66 of the yarn guideway 61. Three shallow air passage slots, 93, symmetrically arranged with the yarn slot 92, are formed in the exterior wall of the inner tubular case 82 axially from the annular air passage 81 forward to a point adjacent the forward end of the extension tube 42. At this end, three holes 94 connect the slots 93 with an annular passage 96 defined by an interior surface 97 of the tubular case member 82 and an outer surface of a relieved portion 102 of the yarn guideway 61 having a reduced outer diameter.

The central bore, designated 100, of the yarn guideway 61 defines the final rigid guide surface engaged by the yam 19 before itengages the needle hooks 13. The guideway 61 terminates at its forwardmost end in a radial surface 98. The inner tubular case member 82 terminates at its forwardmost end in a radial surface 99, located somewhat short or rearward of the radial face 98 of the yarn guideway 61. l

The yarn snubber 71 is biased towards the yarn guideway 61 by a compression spring 106 shown in FIG. 3. The compression spring 106 abuts the bottom of a bore 107 in the rightward leg 45 of the control yoke 41. The spring 106 operates on the yarn feeder tube 22 through a collar 108 set screwed on the exterior of the tube 22 within the notch 43 of the yoke 41. The yarn feeder tube 22 extends through a clearance hole 105 at the base of the bore 107. A stop screw 109 adjustably threaded into an extension 111 of the mounting block 31 provides a lost motion action in stopping the collar 108, and therefore the feeder tube 22 and snubber 71 mounted therein, the slider tube 39 moves forwardly in the guide tube 37. When the collar 108 engages the stop 109 in response to movement of the control yoke 41 and slider tube 39, the yarn snubber 71 is caused to separate away from the conical surface 59 at the entrance of the yarn guideway 61.

The stop collar 108 is provided with a slot 112 which engages a pin 113 pressed into a hole 114 in the right leg 45 of the control yoke 41. The pin 113 prevents the stop collar 108 and therefore the yarn feeder tube 22 from rotating so that the radial slot 56 in the tube is held in alignment with the radial slot 92 in the extension tube air case 42.

Operation of the yarn feeder device 10 may be understood from the foregoing description and the following discussion. Yarn is inserted in the entrance end, designated 104, of the yarn feeder tube 22 and pushed forward until it reaches the ramp 65 near the end 73 of the tube. As the yarn 19 moves forward it runs along the ramp 65, through the slot 92, along the interior surface 57 of the extension 42, into the guideway 61 at the conical entrance surface 59, and then exits the feeder 10 through the yarn guideway 61.

During initial threading of the yarn 19 through the feeder 10, the yarn snubber 71 may be retracted from the conical braking surface 59 of the yarn guideway 61 by either manually pulling on the yarn tube 22 or the collar 108 or pushing the control yoke 41 forward until the collar 108 engages thestop 109 manually or by use of the cable 34. Initial threading of the yarn 19 through the feeder 10 may be assisted by the introduction of pressurized fluid through the fitting 27 for reasons explained below.

During knitting operations when it is desired to introduce a yarn end to the knitting instrumentalities 16, 17, yarn is fed through the feeder 10 by simultaneously admitting air to the fitting 27 and drawing up on the cable 34. Preferably, air is admitted before the cable 34 is operated but this sequence may be reversed when it may be considered desirable or both steps may be started simultaneously. Cams or other timing devices on a particular knitting machine may be employed in known ways to operate a valve to direct pressurized fluid through a conduit to the fitting 27 and a linkage may be used to draw up the cable 34 at the desired time.

Pressurized fluid escaping from the annular passage 96 maintains the axial direction defined by the passage and flows past the end 98 of the yarn guideway 61 forming a vacuum therein. That is, a pressure less than atmospheric as created in the exit end 98 of the yarn guideway 61 to draw yarn through the guideway and direct it straight into the hooks 13 of the needles 16 and 17.

A cam or other conventional means energized on the knitting machine at anvappropriate time causesthe casing 30 of the cable assembly 26 to extend or move leftwardly, as viewed in FIGS. 2 and 3, so that the cable 34 is drawn into the cable anchor 49 and the control yoke 41 is pushed towards the fixed block 31, with the slider tube 39 moving in the guide tube 37. The forward end 21 of the feeder 10 extends toward the needle hooks 13 allowing the guideway 61 to move into close proximity to the needle hooks 13. The compression spring 106 resiliently forces the yarn tube 22 and snubber 71 forward with the control block 41. The stop collar 108 eventually engages the stop screw 109. At this time the yarn snubber 71 remains stationary as the conical entrance 59 of the yarn guideway 61 continues to move forward thereby releasing yam pinched or gripped between the guideway and yarn snubber 71. The feeder 10 continues to move forward until the yarn is completely released and its end 21 is suitably close to the needles 13. When it is desired to interrupt the feeding of yarn, the cable 34 is released and the compression spring 53 causes the device 10 to retract.

As the control yoke 41 retracts rightward, as viewed in the Figures, the compression spring 106 holds the stop collar 108 stationary against the stop screw 109. Further release of the cable 34 causes the gap between the conical entrance 59 of the yarn guideway 61 and the lead end 69 of the yarn snubber 71 to close on the yarn 19. When the compressive force on the yarn exceeds the force developed by the compression spring 106, the stop collar 108 lifts off of the stop screw 109 and eventually resumes the position shown in the Figures.

As illustrated in P10. 4, yarn 19 is clamped or braked between the conical entrance 59 of the yarn guideway 61 and the corresponding conical end 69 of the yarn snubber or gripper 71 to terminate feeding of the yarn. These conical or inclined surfaces 59 and 69 provide a wedging action which assures positive gripping in this area when sufficient tension is developed in the preceding length of yarn in the

needles

13, 14. As the needles 14 carry the yarn 19 away from the feeder 10, the yarn is severed at a point in its path between the snubber 71 and the needles where there is an abrupt change in the path direction such as in the needle area or at the end 98 of the yarn guideway 61. After severance, an end of yarn is positively held between the conical braking surfaces 59 and 69 ready for subsequent introduction to the

needles

13, 14. The trailing yarn end associated with knitted fabric may be directed into the needle hooks 13 by releasing a charge of pressurized fluid to a fitting 27 and through the feeder during and immediately following yarn severance at termination of yarn feeding.

it may be seen that the yarn is severed relatively close to the needles so that only a very short piece of trailing yarn remains to be knitted into the fabric. This minimizes the visible effects of knitting the trailing yarn end in the fabric without benefit of tension.

The slender tubular arrangement of the yarn feeder along with its capability of axial reciprocation and axial brake actuation permits it to be used in relatively confined areas such as at a knitting station already having one or more existing conventional yarn feeders. Additionally, a bank of several yarn feeders constructed in accordance with the invention may be used in a single machine. Owing to the small space requirements in the zone of the needles and the ability to retract from such zone or center of knitting, the feeder may be used to improve knitting efficiency and quality since each feeder may be mounted so that its end extends into a common knitting zone. Thus, the needles are enabled to pick up yarns at a common point or relatively narrow zone, so that stitch control is more uniform.

it is to be understood that the foregoing description of the preferred embodiment of this invention is not intended to be limiting or restricting and that various rearrangements and modifications which may become apparent to those skilled in the art may be resorted to without departing from the scope of the invention as defined in the claims.

What is claimed is:

l. in a knitting machine, a yarn feeding device adapted to introduce a yarn end to the hooks of knitting instrumentalities comprising a yarn guideway having an entrance portion adapted to receive yarn from a supply and an exit portion facing the hooks of adjacent knitting instrumentalities and adapted to guide yarn through its interior towards said hooks, the interior of said exit portion defining the final effective rigid guide surface engaged by said yarn before it enters said hooks, yarn terminating means within said yarn guideway axially movable from a first position at which yarn may pass through said yarn guideway to a second position at which said terminating means is effective to terminate yarn feeding, means to move said yarn terminating means between said first and second positions, and a fluid passage adjacent the exit portion of said guideway adapted to receive fluid from a fluid source and direct such fluid toward said hooks to form a vacuum in the interior of said exit portion and entrain a yarn end and direct it into said hooks.

2. The combination as set forth in claim 1 wherein said yarn guideway is an elongated tube having an exterior which defines the interior of said fluid passage.

3. The combination as set forth in claim 2 wherein said yarn guideway and said fluid passage have circular cross sections concentric with one another.

4. The combination as set forth in claim 3 wherein the exit portion of said yarn guideway terminates in a radial face and said fluid passage terminates in a radial face axially inward of the radial face of the guideway.

5. In a knitting machine, a yarn feeding device for selectively introducing a yarn end to the hooks of knitting instrumentalities and for selectively interrupting the feeding of the yarn to the hooks comprising a yarn feeding tube having a longitudinal axis defining the direction of feed of a yarn end into the hooks, means to selectively drive said yarn into the hooks of said instrumentalities, axially movable yarn terminating means, means for deflecting said yarn from a normal axial path laterally around said yarn terminating means and back to said axial path, surfaces adapted to guide said yarn terminating means for reciprocal motion along said longitudinal axis between first and second positions, means for moving said yarn terminating means between said first and second positions, said yarn terminating means including means in said first position to interrupt feeding of said yarn and in said second position to permit yarn to be fed to said hooks.

6. in a knitting machine, a yarn feeding device for selectively introducing a yarn end to the hooks of knitting instrumentalities and for selectively interrupting the feeding of the yarn to the hooks comprising a yarn feeding tube having a longitudinal axis defining the direction of feed of a yarn-end into the hooks, means to selectively d rive said yarn into the hooks of said instrumentalities, axially movable yarn terminating means, surfaces adapted to guide said yarn terminating means for reciprocal motion along said longitudinal axis between first and second positions, means for moving said yarn terminating means between said first and second positions, said yarn terminating means including means in said first position to interrupt feeding of said yarn and in said second position to permit yarn to be fed to said hooks, said yarn feeding tube being axially movable towards and away from said hooks and said yarn terminating means moving to said second position as said yarn feeding tube moves toward said hooks.

7. The combination as set forth in claim 6 wherein said yarn terminating means includes an axially movable clamping surface adapted to clamp said yarn against a stationary surface when in said first position.

8. The combination as set forth in claim 7 wherein said clamping surface is inclined with respect to said axis to wedge said yarn against said stationary surface upon axial movement toward said stationary surface.

9. The combination as set forth in claim 7 wherein said clamping surface is provided on an end of said movable yarn feeding tube opposite the end closest to said hooks.

10. In a knitting machine, a yarn feeding device for selectively introducing and terminating the feeding of a yarn to the knitting instrumentalities of the machine, said device including a slider member adapted to reciprocate along a direction defined by its longitudinal axis towards and away from the knitting instrumentalities, control block means reciprocating with said slider member, control means mounted on said control block means operable to cause said control block means and slider member to reciprocate, means for receiving pressurized fluid from a fluid source, an elongated central yarn feeding tube adapted to receive yarn from a yarn source, a yarn guideway having a common axis with the longitudinal axis of said yarn feeding tube and disposed between said yarn feeding tube and said knitting instrumentalities, a yarn clamping member at an end of said yarn feeding tube adjacent said yarn guideway and axially reciprocal with respect to said guideway, means to axially move said clamping member relative to said guideway, means defining a yarn path radially outward around said clamping member and radially inward to an entrance end of said guideway, and an annular fluid passage surrounding said yarn guideway at an exit end thereof, said fluid passage communicating with said pressurized fluid receiving means and terminating ad jacent the exit end of said yarn guideway and adapted to direct pressurized fluid from said receiving means axially past said exit end and create a vacuum therein to thereby draw yarn through said feeder tube and guideway and direct it into said knitting instrumentalities.

11. The combination as set forth in claim 10 wherein said clamping member cooperates with the entrance end of said guideway to grip yarn passing therebetween, and stop means to hold said clamping member stationary while said yarn guideway extends toward said knitting instrumentalities.

12. The combination as set forth in claim 11 wherein said stop means is arranged to hold said clamping member stationary after said slider tube and control block have extended a predetermined distance toward said knitting instrumentalities.

13. The combination as set forth in claim 10 wherein said pressurized fluid receiving means is mounted on said control block, and said fluid passage encircles said clamping member.

Claims

1. In a knitting machine, a yarn feeding device adapted to introduce a yarn end to the hooks of knitting instrumentalities comprising a yarn guideway having an entrance portion adapted to receive yarn from a supply and an exit portion facing the hooks of adjacent knitting instrumentalities and adapted to guide yarn through its interior towards said hooks, the interior of said exit portion defining the final effective rigid guide surface engaged by said yarn before it enters said hooks, yarn terminating means within said yarn guideway axially movable from a first position at which yarn may pass through said yarn guideway to a second position at which said terminating means is effective to terminate yarn feeding, means to move said yarn terminating means between said first and second positions, and a fluid passage adjacent the exit portion of said guideway adapted to receive fluid from a fluid source and direct such fluid toward said hooks to form a vacuum in the interior of said exit portion and entrain a yarn end and direct it into said hooks.

6. In a knitting machine, a yarn feeding device for selectively introducing a yarn end to the hooks of knitting instrumentalities and for selectively interrupting the feeding of the yarn to the hooks comprising a yarn feeding tube having a longitudinal axis defining the direction of feed of a yarn end into the hooks, means to selectively drive said yarn into the hooks of said instrumentalities, axially movable yarn terminating means, surfaces adapted to guide said yarn terminating means for reciprocal motion along said longitudiNal axis between first and second positions, means for moving said yarn terminating means between said first and second positions, said yarn terminating means including means in said first position to interrupt feeding of said yarn and in said second position to permit yarn to be fed to said hooks, said yarn feeding tube being axially movable towards and away from said hooks and said yarn terminating means moving to said second position as said yarn feeding tube moves toward said hooks.

10. In a knitting machine, a yarn feeding device for selectively introducing and terminating the feeding of a yarn to the knitting instrumentalities of the machine, said device including a slider member adapted to reciprocate along a direction defined by its longitudinal axis towards and away from the knitting instrumentalities, control block means reciprocating with said slider member, control means mounted on said control block means operable to cause said control block means and slider member to reciprocate, means for receiving pressurized fluid from a fluid source, an elongated central yarn feeding tube adapted to receive yarn from a yarn source, a yarn guideway having a common axis with the longitudinal axis of said yarn feeding tube and disposed between said yarn feeding tube and said knitting instrumentalities, a yarn clamping member at an end of said yarn feeding tube adjacent said yarn guideway and axially reciprocal with respect to said guideway, means to axially move said clamping member relative to said guideway, means defining a yarn path radially outward around said clamping member and radially inward to an entrance end of said guideway, and an annular fluid passage surrounding said yarn guideway at an exit end thereof, said fluid passage communicating with said pressurized fluid receiving means and terminating adjacent the exit end of said yarn guideway and adapted to direct pressurized fluid from said receiving means axially past said exit end and create a vacuum therein to thereby draw yarn through said feeder tube and guideway and direct it into said knitting instrumentalities.