US2988906A - Flat warp knitting machine - Google Patents

Description

June 20, 1961 A. w. H. PORTER FLAT WARP KNITTING MACHINE 6 Sheets-Sheet 1 Filed March 28, 1960 Inventor A W H Porter y I I Mttorneys June 20, 1961 A. w. H. PORTER FLAT WARP KNITTING MACHINE 6 Sheets-Sheet 2 Filed March 28. 1960 Inventor ,4. W/7. porfer' By Mtomeys June 20, 1961 Filed March 28, 1960 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE 6 Sheets-Sheet 3 5 5 5 2/ 2 55 -51 ii1 6/ 26 24 22 50 57 60g 25 Q 55 6 Q a? i 40 f 29 6 55 ',.g 3/3237 53 5f -2 2'7 25 /'7 /5 4/ 754 Inventor AIM/ Pan er June 20, 1961 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, 1960 6 Sheets-Sheet 4 Inventor A. W. H. Porier' Attorneys June 20, 1961 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, 1960 6 Sheets-Sheet 5 Inventor Attorneys June 20, 1961 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, l960 6 Sheets-Sheet 6 Inventor A. W H. Parfer Attorneys FLAT WARP KNITTING MACHINE William Henry Porter, Bnrton-on-Trent, England,

assignor to Hb'ourn-F.N.-F. Limited Filed Mar. 28, 1960, Ser. No. 18,039

Allan priority, application Great Britain Apr. 14, 1959 7 Claims. 01. 66-86) In flatwarp knitting machines having a row of reciprocating hooked needles and one or more rows of guides which are swungto and fro across the row of needles I, for laying the warpthreads in the hooks of the needles, "it isdesirable (for the needles to perform a movement which. includes a dwell when. the needles are at that end of-their stroke at which. the threads are laid into their .h'ooks." The needles cannot usually be motionless during 'thisdwell, but their speed should be considerably less "than that in the remainder of the stroke.

Such a .dwell is very advantageous in that it helps jto ensure that the threads are accurately laid in the .needle hooks before the needle hooks are closed. The

greater the number of guide bars which the machine l1;as,. that,is thegreater the number of rows of guide eyes, Lthe more necessary a dwell becomes to ensure ithatjthere is sufiicient time for the threads leading from all'the different rows offguide eyes to be ,laid in the needle hooks.

It is also essential that the guide eyes should remain ample, three or more guide bars, the period during {yvhichthe guides remain behind the needles must be considerable becausethe outermost row of guide eyes =must move sufliciently far to enable the innermost row nearest to the needles to perform its shogging movefn'ent before "this"row moves back again.

*According to the present invention a flat warp knitting machine with a rowof reciprocating hooked needles carried on a needle bar, and one or more pivotally mounted guide'bars which are swung'to and fro across the row of needles, has its needle bar driven from a "paifio feccentrics, which operate in parallel and one of -whichis rotated at twice the speed of the other, through two connecting rods connecting the eccentrics to a crosshead, and through a mechanism which includes a member connected to the cross-head in a position between the connections tothe cross-head of the two connecting rods and the guide bar or bars are driven from the sanie "pair of'ecoentrics through the connecting rods and the cross-head and through a further mechanism which includes a second member connected to the cross-"head in a position on the side of the connection to the crosshead of the connecting rod of the slower eccentric re- 'm'ote fromthe connecting rod of the faster eccentric.

Preferably the distance between the 'centres of the connections of the first m ember and of the connecting rod of the faster eccentric to the cross-head and the distance between the centres of the connections of the first member and of the connecting rod of the "slower eccentric to the cross-head are in the ratio of substantially 2:1. Further, the distance between 'the'centres 'of the connections o f the first member and of the connecting rod -of the"'slower eccentric and the distance between the centres of the connections of the second member and nf-the connecting rod of the slower eccentric, are substantially equal to each other.

,Un wd St s P t n .0

Patented June20, 1961 2 and some of their associated mechanism is used to drive both the needles and the guides, saves many Working parts in the knitting machine, thus making the machine more compact and cheaper to manufacture. This is an obvious advantage.

The arrangement also has the furtherand more important advantage that it produces particularly satisfactory movements of the needles and of the guides. The curve of movement of the needles plotted against a base of the angle of rotation of the slower eccentric, which revolves once in each knitting cycle, has a very flat peak extending on both sides of the 180 degree point of the cycle of movement. The curve of movement of the guides, on the other hand, approximates to an inverse of the movement of the needles and is 180 degrees out of phase with the curve of movement of the needles.

dwell, it is only necessary. for the innermost .rowof guides, that is the row nearest the row of needles, 'to be 'just behind the row of needles when the shogging movements are -made.' The dwell in the guide movement completely obviatm the necessity, whic'h'would occur if 'the guides made a simple harmonic movement, for the guides to swing far beyond the backs of the row of needles to enable the innermost row of guides to be clear of the row of needles for long enough to enable it to make its shogging movement.

If the guides made a simple harmonic motion in this way, the outermost row of guides in a multi-bar machine would have to swing a very substantial distance away from the row of needles. The threads would therefore,

be drawn by the guides away from the shanks of the needles and this would cause the helices of thread wrapped around the shanks of the needles by the guides to be drawn down the-shanks of the needles. This is most unsatisfactory and tends to cause mislapping of the threads in the hooksof the needles. 7

With the driving mechanism in accordance with the present invention, howeverg as already-explained, the

'- guides do not need to move far beyond the backs of the knitting elements themselves removed to show the .-'Il1is"ar-rangement, by whichithe same pair of eccentrics I the needles and any tendency to drop stitches or mislap due to drawing of the'thread helices down the shanks of the needles is greatly reduced.

An example of a flat warp knitting machine constructed 'in accordance with the present invention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a front elevation of the machine with general structure more clearly; FIGURE 2 is an'end elevation of the machine complete with the knitting elements; I a v FIGURE 3 is a cross-section to a larger scale through the part of the machine showing the driving-mechanism of the needles and guidebars; 7

FIGURE 4 is a cross-section similar to that shown in FIGURE 3, but showing the driving mechanism of reciprocating tongues which open and close the hooks of the needles; v 5

FIGURE 5 is a cross-section also similar to FIGURE 3, but showing the driving mechanism of sinkers;

FIGURE 6 is a timing'diagram showing the of the needles during one knittingcycle; v 1,; FIGURE 7 is a similar diagram, but showing the momotion ,tion of the guide eyes;

FIGURE 8 is another diagram, similar to FIGURE 7, but showing a modified movement of the guide eyes; and

FIGURE 9 is a further diagram to a larger scale than FIGURES 6 to. 8 showing the movement of the needles relatively to the guides when the needles perform the movement shown in FIGURE 6 and the guides perform the movement shown in either FIGURE 7 or FIGURE .8.

The knitting machine shown in the drawings is of the kind in which the hookedknitting needles have tubular .shanks in which rod-like tongues are independently re- ;eiprocated upwards and downwards relatively to the needles to open and close the needle hooks. The invention is, however, equally applicable to flat warp knitting machines of other types. For example, those having bearded needles, latched needles or needles with tongues zlQ fltedin a groove in the needle shank.

.-A s shown in FIGURES l and 2, the machine has a ;main frame 1 extending over its full width. This frame ,is supported at both ends on legs 2 and 3 and also'intermediately on a further leg 4. Above the legs 3 and 4 the frame 1 has integral upwardly and downwardly extending supports 5 and 6 respectively on which sectional warp beams 7 and 8 are rotatably mounted.

The machine is driven in a conventional manner by an electric motor 9 mounted on the left-hand end' of the frame 1. This motor rotates the warp beams 7 and 8 by means of a headstock 10 and a similar headstock adjacent the left-hand end as seen in FIGUREl of the warp beam 8. These headstocks are rotated through a conventional transmission which is notillustrated.

The motor also rotates sprockets carrying pattern chains within a housing 11 at the left-hand end of the frame 1. "The pattern chains move bars 12 to and fro from left to right. The bars 12 are connected to the. guide bars of the machine which are not shown in FIGURE 1 of the drawings, to make these guide bars make shogging and lapping movements in a direction across the width of the machine. Again the pattern mechanism is quite conventional and is not therefore illustrated. Next themotor 9 rotates a roller 12a on which the knitted fabric is wound. Finally the motor 9 rotates two main driving shafts 13 and 14 enclosed within a sump 15 and extending across the whole width of the machine. The driving shafts are driv- -en by means of toothed gearing within a housing 16. The driving shafts are connected together by gearing within the housing 16 in such a way that the shaft 13 is rotated at twice the speed of the shaft 14. The shaft 14 makes the same number of revolutions per minute as the machine makes knitting cycles per minute and the shaft 13 runs at twice this speed- The driving shafts 13 and 14 operate the knitting elements (which are not shown in FIGURE 1) through driving mechanisms illustrated in detail in FIGURES 3 to 5 of the drawings. One of each of these mechanisms is contained within each of the casings 17, 18, 19 and 20 so that the knitting elements are positively driven at four different places across the width of the machine. The driving mechanisms in each of the casings 17 to 20 are the same as each other and therefore the contents of only one casing 17 is illustrated in FIGURES 3 to 5.

' As shown in FIGURE 3 of the drawings a row of hooked needles 21 having tubular shanks are fixed in a sectional die-cast block 22 which is clamped to a needle bar 23. The bar '23 extends over the whole knitting width of the machine and is carried at four separate points along its length by a bracket 24 which extends from a U-shaped lever 25. The U-shaped lever 25 is pivotally mounted by means of a pin 26 on an arm 27 which is .itself pivoted on a fixed shaft 28 which is mounted in the casing 17. A second arm 29 of the U-shaped lever 25 is pivotally connected by a pin 30 to a ball crank lever 31. The bell crank lever 31 is pivoted on a shaft 32 similar to the shaft 28, and its other arm'33 is connected by a pivot pin 34 to a cross-head 35. The left-hand end of the cross-head 35 is connected by a pivot pin 36 to a connecting rod 37. The connecting rod 37 has at its lower end a strap 38 which surrounds an eccentric 39 on the driving shaft 13. Towards its right-hand end the crosshead 35 is pivotally connected by a pin 40 to a second connecting rod 41. The connecting rod 41 has a strap 42 at its lower end which surrounds an eccentric 43 on the driving shaft 14; Six rows of guide eyes 44' are mounted on six separate guide bars 45 to 50. The guide bars 45 to 50, as already mentioned, are connected by the bars 12 to the pattern mechanism. They are mounted so that they can slide to and fro across the width of the machine, that is along the row of needles 21, on a carrier 51 which is supported by prongs 52 having a back connectingpiece 53 which is pivotally connected by a'pin 54 to arms 55 projecting upwards from the casing 17. The lower end 56 of the carrier 51 is pivotally connected by a pin 57 to a push rod 58. The right-hand end of the'push rod 58, as seen in FIGURE 3 of the drawings, is pivotally connected by a pin 59 to a bell crank lever 60. The bell crank lever'60 is mounted on a shaft 60a and is connected by an adjustable pivotal joint, which consists of a pin 61 whichpasses through a slot 62, to a further conneetingrod 63. The lower end of the connecting rod 63 is. connected by a pin 64 to the right-hand end of the cross-head 35. This end of the cross-head 35 projects beyond the pin 40 by which it is connected to the connecting rod 41.

The distance between the centres of the pins 36 and 34 is twice the distance between the centres of the pins 34 and 40 and the distance between the pins 40 .an d 64 is substantially equal to the distance between the centres of the pins 34 and 40. I I

The eccentrics 39 and '43 have the-same eccentricity aseach other and both are at their top dead centre'positions at the same instant. When the shaft 13', and with it the eccentric 39, is rotated at twice the speed of the shaft 14 and the eccentric 43, as already described, the needles 21 reciprocate in a direction along the lines-of their shanks and perform the movement shown in FIG- URE 6 of the drawings. This figure shows therheight of the needles above their bottom dead centre position plotted on a base which shows the rotation of the shaft 14 in degrees from a datum position. It will be seen from FIGURE 6 that the needles move in a direction towards the guide eyes 44 fairly rapidly. They then dwell near their uppermost position with only a very slight downward movement taking place and they then move rapidly downwards again. The guide eyes perform a curve of movement which isvery nearly an exact mirror image of that of the needles, but displaced from it by degrees. This guide movement is very important and gives very satisfactory results. Theguide eyes remain in a position at the backs of the needles, that is on the closedside of the needle hooks and the left-hand end of the swing as shown in FIGURE 3 of the drawings. They then swing rapidly to the right as shown in FIGURE 3 of the drawings to the fronts of the needles and back again to the left where they remain almost stationary for some considerable time until the cycle of movement is repeated. I

,As shown in FIGURE 4 of the drawings a row of tongues 65 which lie inside the tubular shanks of the needles 21 are fixed to a tongue bar 66. The tongue bar 66 is supported atfour points along its length .by a bracket 67 extending upwards from a U-shaped lever 68 similar to the lever 25 carrying the needles 21. The lever 68 is supported from a pivoted arm 69 similar to the arm 27 and this is also pivoted on the shaft 28. Anarm 70 of the lever 68 is pivoted by apin 71 to a bell crank lever 72 similar to the bell crank lever 33. The bell crank lever 72 is pivoted on the shaft 32. The righthand end of the bell crank lever 72 is pivotally connected by a pin 73 to a cross-head 74 which is in'turn connected by connecting rods 75 and 76 to eccentrics 77 and "78 respectively on the shafts 13 .and 14.

"The throws of the eccentrics 77 and 78 and their angular relationship with each other are adjusted so that the tongues move relatively to the needles in such a way that the hooks of the needles close just as, the needles start to move downwards at the right-hand side of their curve of movement shown in FIGURE 6 of the drawings and to a sinker-bar 82 which is supported at four points along its length on an arm 83 which is pivotally connected by a .pin 84 to a further arm 85 mounted on a fixed shaft 86. The right-hand end of the arm 83, as seen in FIG- URE 5 of the drawings, has a slot 87 through which a pin 88 passes. The pin 88 is fixed to a lever 89 which is pivoted on the shaft 32. The lever 89 is the same as the bell crank levers 33 and 72 for production reasons: in the mechanism for driving the sinkers, however, its left-hand arm 90 is not used. In the same way, in the mechanisms for driving the needles and the tongues the opening in which the pin 88 is fixed is also not used. The end of the lever 89 is connected by a pin 91 to a cross-head 92 similar to the cross-head 74. The crosshead 92 is in turn connected by connecting rods 93 and 94 to eccentrics 95 and 96 on the shafts 13 and 14. Here again the angular positions of the eccentrics 95 and 96 are adjusted to provide the required sinker movement. This may vary in accordance with the nature of the fabric being knitted, but is in general similar to that described in United States Patent No. 2,292,287, to Peel and Mor- IlSOll.

For knitting some fabrics it will not be necessary to employ all six of the guide bars 45 to 50. In many cases in fact all that will be necessary are two guide bars with their associated rows of guide eyes. Under these circumstances it is not necessary for the guides to have a long dwell whilst they are at the backs of the needles to allow the shogging movement of the guide eyes to take place, and it is better, therefore, that the movement shown in FIGURE 8 of the drawings with its long dwell and its consequent rapid acceleration of the guides should be avoided. When only two guide bars are used a simple harmonic motion is more satisfactory. The mechanism shown in FIGURE 3 of the drawings can very easily be adapted to take care of this eventuality. All that is necessary is for the rod 63 to be provided with an extension 97 shown in dotted lines in FIGURE 3 of the drawings and also the connecting rod 41 must be provided with an additional bush 98. To change the motion of the guides over from that shown in FIGURE 8 of the drawings to a simple harmonic motion shown in FIGURE 7 of the drawings, the pin 64 is removed from the position in which it is shown in FIGURE 3 and is inserted instead through the bush 98 and through a corresponding bush in the extension 97 on the rod 63. In this way the bell crank lever 60, and the remainder of the mechanism for oscillating the guide bars, is connected only to the eccentric 43. The eccentric 39 has no further effect. The guide thus performs a simple harmonic motion shown.

Curve A in FIGURE 9 shows the curves of movement of the needles and guides shown in FIGURES 6 and 8 of the drawings compounded together. In fact what has been done is to provide the needle with a movement equal in magnitude, but opposite in direction, to that of the guides at any given instant. The curve thus shows the movement of the needle relatively to the guides if the guides were fixed. It will be seen from the steep portion of the curve A at the left-hand side of the drawing that the guides remain practically at the limit of their movement to the backs, that is on the closed sides of the needle hooks, for some considerable time. The movement across the row of needles is then substantially horizontal.

It is during the time that'the needles are moving along \'the portion of the left-hand-side of the curve A with the guides behindthe needle hooks that shogging of the guides takes place.

Curve B in FIGURE 9 is similar to curve-A, but shows the movement ,of the needlesvrelatively tothe guides when the guides perform the simple harmonic motion shown in FIGURE 7 of the drawings.

From this it will be seen that the needle passes much more rapidly towards the guides so that the guidesjhave less clearance from the needles for a shorter time during which they can make their shogging movement.

Since,.however, the; simple harmonic motion is onlyuused whenthere aretwo rows of guide eyes, this shortening of the time does not do any harm.

I claim:

1. In a flat warp knitting machine of the type comprising a row of reciprocating hooked needles, a needle bar carrying said hooked needles, at least one guide bar, and means pivotally mounting said guide bar for swinging movement to and fro across the row of needles, the combination of first and second eccentrics, drive means for rotating said eccentrics with the second turning at twice the speed of the first, a cross-head, first and second connecting rods connecting said first and second eccentrics respectively to said cross-head at points longitudinally spaced therealong, first mechanical means connected between said needle bar and a point on said cross-head between the connections to said cross-head of said two connecting rods, and second mechanical means connected between said guide bar and a point on said cross-head lying on the side of the connection of said cross-head to said first connecting rod which is remote from its connection to said second connecting rod.

2. A flat warp knitting machine according to claim 1, in which the distance between the centers of the connections of said first mechanical means and of said second connecting rod to said cross-head, and the distance between the centers of the connections of said first mechanical means and of said first connecting rod to said crosshead, are substantially in the ratio of two to one.

3. A flat warp knitting machine according to claim 2, in which the distance between the center of the connections of said first mechanical means and of said first connecting rod to said cross-head, and the distance between the center of the connections of said second mechanical means and of said first connecting rod to said cross-head, are substantially equal to each other; whereby the connections of the two said members to the cross-head perform movements which are substantially the inverse of each other and are degrees out of phase.

4. A flat warp knitting machine according to claim 1, in which said mechanical means comprises an arm in which its pivotal connection to said cross head is located, and said arm carries an extension toward said first connecting rod, and bushes in said extension and in said first connecting rod, said bushes enabling said arm and said first connecting rod to be connected together in place of the connection between said arm and said cross-head.

5. In a flat warp knitting machine of the type comprising a row of reciprocating needles having shanks and hooks with an open and a closed side, a needle bar carrying said needles at the ends of said shanks remote from said hooks and reciprocating said needles in a direction parallel to said shanks, at least one guide bar, and means pivotally mounting said guide bar for swinging movement to and fro across said row of needles from said closed side to said open side, the combination of first and second eccentrics, drive means for rotating said eccentrics with the second turning at twice the speed of the first, a crosshead, first and second connecting rods connecting said first and second eccentrics to said cross-head at points longitudinally spaced therealong, first mechanical means connected between said needle bar and a point on said I cross headf between the connections. to" saidi cross-head of said two connecting rods; andsecondrnechanical means connected between said guide bar and: a point on said cross-head lying on the side of the connection of said 1 cross-head to said first connecting rod which is're'mote from its connectiontosaid second connecting'rod', said first mechanical means and said second'm'echanical'means being so arranged that when the needle bar is at the limit of itsmov'ement in the direction in which saidhooks lead said shanks', said guide bar is at the limit of itsmovement' inane direction in-wliich it moves from said closed side to said open side of saidneedles.

6: A flat warp knitting machineaccording" toclaim 5,

" in which said eccentrics are both at their top dead-center positionsat' the same instant, once during each-rotation of said first eccentric:

' 7. A' flat Warp-knitting machine according to claim 5, iii-which both said guide bar and said needle bar experiencea dWell-whenthey are substantially in the positions which they occupy when 'said needle bar has completedits Peel et al. Aug. 4, 1942 Held Jan; 19, 1960

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