US3668903A - Straight bar knitting machines - Google Patents

Abstract

Production of rib to plain fabric on a straight bar knitting machine having quality control mechanism for the fabric to be made at different qualities, starting the rib fabric with first and second yarns by successive motions of the frame needles after pre-setting welt quality control mechanism to an abnormally tight quality and rendering the mechanism effective by pattern control means, and having catch bar cam controlled means operable for abnormally retracting the sinkers and cam shaft shogging means for rendering the cam controlled means effective at required times.

Description

[ 1 June 13, 1972 United States atent Marriott [54] STRAIGHT BAR KNITTING MACHINES Lambach.................

wm efe n mm 0 m w 29 66 99 NH 24 1 47 83 95 63 33 2,629,993 3/1953 [72] Inventor: Eric Walter Marriott, Shepshed, England William Cotton Limited March 6, 1970 L73] Assignee:

[22] Filed:

Primary Examiner-Ronald F eldbaum Attorney-Larson Taylor & Hinds ABSTRACT 21 Appl. No.:

Production of rib to plain fabric on a straight bar knitting machine having quality control mechanism for the fabric to be g the rib fabric with first and ns of the frame needles after mechanism to an abnormally ht quality and rendering the mechanism effective by pattern g catch bar cam controlled means ble for abnormally retracting the sinkers and cam shaft ing means for rendering the cam controlled means effective at required times.

UNITED STATES PATENTS 8 Claims, 11 Drawing Figures l,878,869 9/1932 Lieberknecht................... ....66/82 PATENTEDJuu 1 3 I972 SHEET '4- UF 8 PATENTEDJUN 1 3 I972 SHEET 5 [IF 8 PATENT EDJUN 13 m2 SHEET 7 BF 8 FIG.|O

CROSS REFERENCES TO RELATED APPLICATIONS Reference is made to British Pat. application No. 12362/69 of Mar. 8th 1969, William Cotton Limited, from which priority is claimed. 1 I

. This invention is for improvements in or relating to straight bar knitting machines of a kind which are adapted by the use of frame needles and spaced machine needles for making rib fabric onto which plain fabric is knitted in the same machine.

For knitting, particularly the plain fabric, quality or stitch size adjustments to suit requirements are effected by usual quality control mechanism which adjusts the needle bar during the draw period nearer to or further away from the sinker head, i.e., nearer to or further away from the usual beard presser edge, these adjustments being possible within limits with the needles continuing to have satisfactory pressing relation with the usual beard presser edge at the 'beard pressing stage. It is usual in rib knitting forastarting edge to include a starting edge welt course which is knitted on frame needles only and is tight in order to provide a good edge for the rib. However if a certain degree of tightness is exceeded, the normal catch bar motions will either cause .undue strain on the yarn and/or prevent the needle beards from being closed properly at the pressing stage which can prevent casting off of old loops resulting in fabric faults. Consequently there is an undesirable limit to the degree of tightness that can be obtained.

An object of the invention is to provide a method of and means for knitting fabric with a desired particularly tight starting'edge.

The invention provides a method of knitting which consists in knitting rib fabric on two co'operating sets of needles of which one set is of bearded needles, knitting on to the rib fabric by the set of bearded needles any one of a range of plain fabrics having suitable different qualities by adjustment of the set of bearded needles in opposite directions arallel to a constant yarn sinking motion by sinkers, forming by the set of bearded needles a starting edge for the rib fabric at a quality which is tighter than the tightest of said different qualities, and

I for. this purpose further adjusting the set of bearded needles in the same direction as that of said yarn sinking motion so that, for the yarn feeding stage, yarn is fed to suit the tighter quality, and retracting the sinkers at the beard pressing stage to sufficient extent to allow displacement of the sunk yarn with the needles towards a presser edge so that beard pressing can be effected properly and undue strain can be avoided between the yarn and the needles. In'one arrangement forming of the starting edge for the rib fabric includes knitting on the set of bearded needles, only one complete starting edge welt course at said tighter quality. In another arrangement, forming the starting edge for the rib fabric also includes knitting, on the set of bearded needles, two or more plain stitch courses of the tighter quality, for forming the starting edge as a roll welt.

The invention also provides the production of successively knitted rib and non-rib fabric in a straight bar knitting machine having quality control means enabling the fabric to be produced at any one of a plurality of different qualities within a range of permitted tightness and slackness, wherein the fabric is started by forming at least one starting edge welt course after adjusting the welt quality control means to an abnormal tightness setting, and thereafter, during the beardpressing advance of the needles towards the sinker head, compensating for the abnormal tightness by imparting an abnormal retracting motion to the sinkers.

The invention also provides, in a straight bar knitting machine of the kind having means for successively producing rib fabric and non-rib fabric at any one of a range of normal qualities or stitch sizes, means for causing a starting edge welt course to be of abnormal tightness comprising a welt quality control device preset to an abnormally tight quality, pattern control means for rendering the welt quality control device effective at least forthe starting edge, catch bar mechanism for control of sinkers, cam operated means including a rib cam, a

tionary cam follower roller connected to the catch bar, an axially movable cam follower roller axially coupled to the axially stationary cam follower roller, and pattern control means for operating a shifting device to shift the axially movable cam follower roller. Conveniently also the quality control device is associated with alower one of upper and lower main cam shafts, and the pattern control means for the welt quality control device is a lower one of upper and lower pattern control means. The rib cam, non-rib cam, welt cam and fashioning cam are conveniently on the upper draw cam shaft, and the pattern control means for the shifting device is the upper one of the upper and lower pattern control means.

The above and other features of the invention set out in the appended claims are incorporated in the construction which will now be described, as a specific embodiment with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic detail of a bearded frame needle and a sinker in yarn-feeding position for the first time to start forming a tight starting edge of fabric according to the inventron.

FIG. 2 is a similar view to FIG. 1 indicating sinker adjustment to allow for satisfactory conditions at the beard-pressing stage.

FIG. 3 is a similar view to FIG. 1 showing the yarn-feeding position for the second time.

FIG. 4,is an enlarged detail view showing the knock-over position after the second feed of yarn.

FIG. 5 is a general cross section of relevant parts of a straight bar knitting machine of the kind referred to.

' FIG. 6 is a detail view of means for obtaining horizontal movements of needles.

FIG. 7 is a detail view of welt quality control mechanism.

FIG. 8 is a sectional view of part of the straight bar knitting machine showing catch bar control mechanism.

FIG. 9 is a detail view showing further parts of the catch bar control mechanism.

FIG. 10 is a side view of FIG. 9.

FIG. 1 l is a detail view of cam shaft shogging means.

According to the invention a method of knitting is carried out on a machine of the kind referred to which consists in knitting rib fabric on bearded frame needles and machine needles followed by knitting on the bearded frame needles, onto the rib fabric, any one of a range of plain fabrics having suitable different qualities by adjustment of the bearded frame needles either in one direction or the other'parallel to the usual yarn sinking motion by sinkers. A starting edge for the rib fabric includes first supplying yarn to the frame and machine needles and thereafter forming one, two or more consecutive plain stitch courses on the frame needles only, at a quality which is tighter than the tightest of the different qualities of the plain fabric knitted onto the rib fabric.

For obtaining the tighter quality, the bearded frame needles 1, FIGS. 1 and 3, are adjusted further than usual in the same direction as that of said yarn sinking motion i.e., away from the usual presser edge 2 of the sinker head 3, so that, for the yarn feeding stage, yams Y and Y1 are fed to suit the tighter quality.

At a later stage, the sinkers 4 are caused to have a retracting movement to such an extent that when the bearded frame needles 1 move towards the presser edge, FIG. 2, they carry the sunk yarn Y with them and this ensures satisfactory pressing of the beards la and avoids undue strain between the needles 1 and the yarn Y, and likewise in respect of the yarn Y, so that the starting edge represented at 5 in FIG. 4 is of the required tighter quality.

A straight bar knitting machine for carrying out the method is represented in FIG. 5 showinga bearded frame needle 1 of a row of such needles in a needle bar 6, the sinker head 3 with presser edge 2 and sinkers 4. Rib or machine needles are indicated at 7 and are mounted and controlled in known manner.

The needle bar is mounted and controlled also in known manner including mounting on arms such as 8 for imparting raising and lowering movements to the needles, and on arms such as 9, FIG. 6, for imparting movements of the needles towards and away from the sinker head 3 and presser edge 2. For the latter purpose the arms 9 are connected to a lever 10 which is connected to a cam follower lever 11 with cam follower roller 12 engaging a disc cam 13 on a main cam shaft 14 of the machine. The cam follower lever 1 l is also connected to a short arm 15 on a quality shaft 16.

Welt quality control mechanism in the machine is'shown in FIG. 7 and comprises said quality shaft 16, a short arm 17 having a cam follower roller 18 engaging a quality cam 19. This mechanism is of known construction and includes a quality control adjusting screw 20 which can be pre-set to control through the intermediary of the arm 17, the quality shaft 16 and the cam follower lever l l, the quality setting of the needles 1 during the draw, that is to say it determines the distance of the needles from the sinker head 3 and presser edge 2 which in turn determines the stitch size or extent to which yarn is sunk by the sinkers between the needles.

This welt quality control mechanism is brought into effect when required under control of a disc control mechanism 21 acting on a control lever 22 through a link 23 and a cam sleeve 24 to swing a finger 25 to a position under a lower projecting end 20a of the adjusting screw 20. This causes movement of the roller 19 to turn the quality shaft 16 which moves the cam follower lever 11 to move the needles to the required quality position.

ln the present instance the adjusting screw 20 is pre-set manually for the desired abnormally tight quality i.e., to set the needles spaced an abnormal distance from the presser edge 2. Thereafter the disc control mechanism 21 by a control bit on a disc acts on the control lever 22 at the required time to render the quality mechanism efi'ective for the starting course of the fabric.

For the purpose of effecting the retracting movement of the sinkers 4, modified catch bar control mechanism is provided in a manner hereinafter described.

The usual catch bar mechanism, FlG. 8, comprises the usual catch bar 3l, for releasable engagement with notches 4a in the sinkers 4, a compound cam follower lever 33 pivoted on a shaft '34 and having an axially stationary cam follower roller 35 for engaging different cams at different times on an axially movable main cam shaft 37. In this example the shaft 37 is an upper one of two such main cam shafts. There is also a second cam follower lever 38 having a cam follower roller 39 for engaging said cams on said shaft 37, and the two cam follower levers 33 and 38 are inter-connected by spring means 41.

As shown in FIG. 10 there are usually three earns 36, 40 and 42 for use when making the rib fabric, the plain fabric and when fashioning, respectively. In addition there is provided a further cam 43 for use when making said one, two or more plain stitch welt courses, and this welt cam 43 has a fall for providing the retracting movement of the sinkers. This cam 43 is engageable at the required times when the shaft 37 is shogged, i.e., moved axially, by the axially stationary cam follower roller 35 which is carried by the cam follower lever 33. There is also a cam follower roller 44 which is shiftable onto and off the cam 40 by a pattern control mechanism comprising a forked bell crank lever 45 which is connected by a link 46 to a control lever 47 which is under control of control bits on a top disc control mechanism 48, FIG. 9.

The cam shaft is adapted to be shogged when required by known shogging means such as shown in FIG. 1 l, and in which selection is obtained from pattern control mechanism which causes removal of a latch 50 from the position shown, where it holds a cam follower roller 51 clear of a side face cam 52, to an inoperative position where it allows the roller 51 to spring to the dotted position opposite the side face cam 52. As the shaft 37 rotates, the roller 51 acts an an abutment against which the cam 52 rides to cause the shaft 37 to be shogged to the right. In further rotation of the shaft 37 a cam 53 causes return of the roller 51 to its initial position and the latch is reapplied. In this position the roller 51 acts on a side face cam 54 to cause the shaft 37 to be shogged to the left.

Following operation of the welt cam 43 the cam shaft is shogged in usual manner from neutral to the right in FIG. 5 for the cam 43 to move to the right, away from the roller 35, and for the rib cam 36 to engage the roller 35 while the remainder of the rib fabric is formed. Then the cam shaft is shogged back to neutral and the roller 44 is shifted onto the plain fabric cam 40, which has a profile greater than the cam 43, and at required times the cam shaft is shogged from neutral to the left for fashioning by engagement of cam 42 with roller 35 afler which the cam shaft is shogged back to neutral. For the starting of the next rib welt the cam shaft shogs from neutral to the right to re-engage the welt cam 43 with the roller 35. Roller 44 is re-positioned to inactive position while the rib welt is formed.

It will be thus seen that when it is required to start the rib fabric, the disc control mechanism 21 renders the welt quality control mechanism effective for the required abnormally tight quality. Yarn is fed as described and thereafter the cam shaft is shogged to render the welt cam 43 operative on the roller 35 to retract the sinkers 4. This is repeated for at least a second feed of yarn to produce a complete knitted welt course at the abnormally tight quality. If a roll welt is required there are further repeats of the operations for additional yarn feeds to produce several complete plain courses at the abnormally LII tight quality.

What we claim is:

l. A method of knitting rib fabric onto which non-rib fabric is to be knitted by use of two sets of needles including a set of bearded needles and sinkers and wherein for the non-rib fabric a constant yarn sinking motion is applied to the sinkers and the bearded needles are adjustable in a direction parallel to the yarn sinking motion to provide for the non-rib fabric having any one of a plurality of different stitch qualities, which method includes forming a starting edge for the rib fabric at a stitch quality which is tighter than any of the stitch qualities of the non-rib fabric by first feeding a length of yarn to the needles to suit the tighter stitch quality, adjusting the bearded needles in the same direction as the yarn sinking motion to suit the tighter stitch quality, sinking the yarn between the needles to required limited extent, advancing the bearded needles for pressing of the needle beards, and retracting the sinkers to allow such advance in which the needles carry the sunk yarn with them.

2. A method according to claim 1 which includes, for forming the starting edge for the rib fabric, knitting on the set of bearded needles only one complete starting edge welt course at said tighter quality.

3. A method according to claim 1 which includes, for forming the starting edge for the rib fabric as a roll welt, knitting on the set of bearded needles two or more plain stitch courses of the tighter quality.

4. The production of successively knitted rib and non-rib fabric in a straight bar knitting machine having quality control means enabling the fabric to be produced at any one of a plurality of different qualities within a range of pennitted tightness and slackness, wherein the fabric is started by forming at least one starting edge welt course after adjusting the welt quality control means to an abnormal tightness setting,

and thereafter, during the beard-pressing advance of the needles towards the sinker head, compensating for the abnormal tightness by imparting an abnormal retracting motion to the sinkers.

5. A straight bar knitting machine having means for successively producing rib fabric and non-rib fabric at any one of a range of normal qualities or stitch sizes, and means for causing a starting edge welt course to be of abnormal tightness, comprising a welt quality control device pre-set to an abnormally tight quality, pattern control means for rendering the welt ,quality control device effective at least for the starting edge,

roller connected to the catch bar, an axially movable cam follower roller axially coupled to the axially stationary cam follower roller, and pattern control means for operating a shifting device for shifting the axially movable cam follower roller.

7. Means according to claim 5 wherein the quality control device is associated with a lower one of upper and lower main cam shafts, and having pattern control means for the welt quality control device comprising a lower one of upper and lower pattern control means.

8. Means according to claim 5 to wherein the rib cam, the non-rib cam, and welt cam, and the fashioning cam, are on an upper main cam shaft, and pattern control means for a shifting device comprises an the upper one of upper and lower pattern control means.

Claims (8)

1. A method of knitting rib fabric onto which non-rib fabric is to be knitted by use of two sets of needles including a set of bearded needles and sinkers and wherein for the non-rib fabric a constant yarn sinking motion is applied to the sinkers and the bearded needles are adjustable in a direction parallel to thE yarn sinking motion to provide for the non-rib fabric having any one of a plurality of different stitch qualities, which method includes forming a starting edge for the rib fabric at a stitch quality which is tighter than any of the stitch qualities of the non-rib fabric by first feeding a length of yarn to the needles to suit the tighter stitch quality, adjusting the bearded needles in the same direction as the yarn sinking motion to suit the tighter stitch quality, sinking the yarn between the needles to required limited extent, advancing the bearded needles for pressing of the needle beards, and retracting the sinkers to allow such advance in which the needles carry the sunk yarn with them.

2. A method according to claim 1 which includes, for forming the starting edge for the rib fabric, knitting on the set of bearded needles only one complete starting edge welt course at said tighter quality.

3. A method according to claim 1 which includes, for forming the starting edge for the rib fabric as a roll welt, knitting on the set of bearded needles two or more plain stitch courses of the tighter quality.

4. The production of successively knitted rib and non-rib fabric in a straight bar knitting machine having quality control means enabling the fabric to be produced at any one of a plurality of different qualities within a range of permitted tightness and slackness, wherein the fabric is started by forming at least one starting edge welt course after adjusting the welt quality control means to an abnormal tightness setting, and thereafter, during the beard-pressing advance of the needles towards the sinker head, compensating for the abnormal tightness by imparting an abnormal retracting motion to the sinkers.

5. A straight bar knitting machine having means for successively producing rib fabric and non-rib fabric at any one of a range of normal qualities or stitch sizes, and means for causing a starting edge welt course to be of abnormal tightness, comprising a welt quality control device pre-set to an abnormally tight quality, pattern control means for rendering the welt quality control device effective at least for the starting edge, catch bar mechanism for control of sinkers, cam operated means including a rib cam, a non-rib cam, a fashioning cam, and a welt cam, said welt cam having a fall for abnormal retraction of the catch bar and sinkers and selection control means for selective control of the cams including for selection of the welt cam to operate during advance of the needles towards the sinker head.

6. Means according to claim 5 wherein the selection control means comprises a pattern controlled shogging device for shogging the cam shaft, an axially stationary cam follower roller connected to the catch bar, an axially movable cam follower roller axially coupled to the axially stationary cam follower roller, and pattern control means for operating a shifting device for shifting the axially movable cam follower roller.

7. Means according to claim 5 wherein the quality control device is associated with a lower one of upper and lower main cam shafts, and having pattern control means for the welt quality control device comprising a lower one of upper and lower pattern control means.

8. Means according to claim 5 to wherein the rib cam, the non-rib cam, and welt cam, and the fashioning cam, are on an upper main cam shaft, and pattern control means for a shifting device comprises an the upper one of upper and lower pattern control means.

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