US2957326A

US2957326A - Warp knitting machines

Info

Publication number: US2957326A
Application number: US726701A
Authority: US
Inventors: Porter Allan William Henry
Original assignee: HOBOURN F N F Ltd
Current assignee: HOBOURN F N F Ltd; HOBOURN-F N F Ltd
Priority date: 1957-02-26
Filing date: 1958-04-07
Publication date: 1960-10-25
Anticipated expiration: 1977-10-25

Description

Oct. 25, 1960 A. w. H. PORTER WARP KNITTING wmcumss 4 Shets-Sheet 1 Filed April 7, 1958 Inventor ALLAN \l 1.\'\. PORTER y LLmwe \LWXDO; 5 Attorney 1950 A. w. H. PORTER 2,957,326

WARP KNITTING MACHINES Filed April 7, 1958 4 Sheets-Sheet 2 Inventor LuxN w. H. PbaTE M y MML'M Attorney Oct 1960 A. w. H, PORTER 2,957,326

WARP KNITTING MACHINES Filed April '7, 1958 4 Sheets-Sheet 3 Inventor ALLAN w. H. PORTER drAfiLl MhMfls Attorney Oct. 25, 1960 A. w. H. PORTER 2,957,326

WARP KNITTING MACHINES Filed April 7, 1958 4 Sheets-Sheet 4 Inventor ALLAN W.H- P R R y L MLMJF olS Attorney United States Patent WARP KNITTING MACHINES Allan William Henry Porter, Burton-on-Trent, England, assignor to Hobourn-F.N.F. Limited Filed Apr. 7, 1958, Ser. No. 726,701 Claims priority, application Great Britain Oct. 7, 1957 7 Claims. (CI. 6686) In high speed flat warp knitting machines having a row of reciprocating hooked needles, the warp threads are commonly laid in the hooks of the needles by guide eyes which are swung to and fro transversely through the row of needles and which make lapping movements along the row of needles.

As the guide eyes swing across the row of needles, each individual eye passes through the space between two adjacent needles. For this reason, the eyes must be very thin since the space between the needles is narrow, and such conventional guide eyes generally consist of a finger stamped out of thin metal sheet with a hole stamped in the fingernear its end. The guide eyes are arranged with the holes coaxial with each other and with this common axis parallel to the row of needles, that is at right'angles to the needle shanks. Thus, the holes in the guide eyes lie in planes which are parallel to each other and parallel to the planes of the needle hooks.

In order to pass through the holes in conventional guide eyes, the warp threads undergo a double change in direction during their passages to the needles so that as the Warp threads are consumed and pass through the guide eyes, they rub against both the upper and lower edges of the holes in the guides. This rubbing is likely to cause damage to threads which consist of very fine filaments. The double change in direction of the threads also cause a frictional drag on the threads which increases their tension and reduces the effectiveness of a tension bar or any other device which may be provided to even out the tension in the threads throughout the knitting cycle.

According to the present invention, in a high speed fiat warp knitting machine which has a row of reciprocating compound needles, the warp threads are laid in the hooks of the needles by a row of guide eyes, each with an opening, which move to and fro across the row of needles and while so doing pass beyond the tops of the needle hooks, and the guide eye openings all lie in a common plane and are positioned in such a way that the movement of the warp threads through the holes takes place in planes parallel to the planes of the needle hooks. For example the openings in the guide eyes may lie in a plane perpendicular to the shanks of the needles so that the axes of the openings are substantially parallel to the shanks of the needles.

With this arrangement, the guide eyes do not interengage between the needles at any time during their movement as was previously the case and the guide eyes do not, therefore, have to be restricted in thickness. to enable them to pass between the needles.

High speed fiat warp knitting machines are commonly of a very fine gauge having twenty-eight needles to the inch, and difficulties have previously occurred due to differential expansion of the needle bar holding the row of needles and the guide bar holding the row of guides, causing interference to take place between the guides and needles. By arranging the guide eyes above the "ice 2 tops of the needles, the possibility of such interference is completely avoided.

Further, since the movement of the warp threads through the openings in the guide eyes takes place in planes parallel to the planes of the needle hooks, there is only a slight alteration of direction of the warp threads as they pass through the guide eyes so that little rubbing and consequent wear takes place and the possibility of damage occurring to the threads is lessened. There must, of course, be an alteration in the direction of the threads when the guides make shogging movements along the row of needles so that the threads lie obliquely along the row of needles, but the changein direction of the threads as they leave the guide eye opening is, of course, inherent in any Warp knitting machine andcannot be avoided.

The reduction of wear of thethreads is of particular advantage when knitting modern low twist yarns since it one of the filaments of the yarn is broken by rubbing against a guide eye, thebroken end tends not to be 03.1? ried through the eye by the remaining filaments but is bunched up in the eye until the whole thread is stretched and broken.

With conventional guide eyes, with their'holes lying in planes parallel to the planes of the needle hooks, the threads extend either from the edges of the holes furthest from the needles or from the edges of the eyes surrounding the holes and closest to the needles depending on the direction of shogging or lapping movement of the eyes. That is to say, in a machine in which the needles are vertical, the threads are laid from two diiferent heights relative to the needle hooks which is not satisfactory.

When the openings in the guide eyes are positioned in such a way that the movement of. the warp threads through the openings takes place in planes parallel to the planes of the needle hooks, the .guide eyes can be made so that no part of them-extends into the path of the warp threads after the threads have left the openings themselves, and also the eyes can be symmetrical so that the parts of the eyes on both sides of the openings are at the same distance from the hooks of the needles. Therefore, the threads leave the guide eyes at a constant distance from the hooks of the needles irrespective of thedirection of lay of the threads along the row of needles, that is irrespective of the direction of shogging or lapping movement of the eyes.

A further advantage of the feature that no part of the guide eyes extends into the path of the warp threads between the openings in the'eyes and the needles 'is that interference between the threads leaving the eyes in one guide bar and the guide eyes in other guide bars in multibar machines during the longitudinal lapping or shogging movements of the guide eyes is avoided. Any intenference'between the thread leaving any one guide eye and the adjacent guide eyes in the same guide baris also avoided.

Because interference between the various guide eyes and the-threads is avoided in this way, the relative motion between the needles and the guide eyes may be greatly simplified. Both the needles and the guidescan be reciprocated by a driving mechanism incorporating only 'a single eccentric fordriving the needles and a second single eccentric for drivng the guides. Thus, both the needles and guides execute a simple harmonic motion.

Preferably, these simple harmonic motions are in phase with each other, the guide eyes reaching the limit of their movement in front of the needles at the same time as the needles reach the limit of their movement towards the guide eyes and this produces the result that the component across the row of needles of the movement of the needles relative to the guide eyes is efiectively along a straight line. i i V In a knitting machine having two or more guide bars,

each carrying a row of guide eyes, the openings in all the guide eyes may lie in a common plane which is parallelto' the plane in which the lines. ofmovement of the needles relativeto the guide eyes lie. By arranging the openings in the guide eyes intwo difierent guide bars in thisway, the open ngsin the guide eyes in all the guide bars passacross the tops of the hooks of the. needles at the same distance as each other from the hooks and, in consequence, the threads laid around the shanksof the needles bythe eyes in the diflerent guide bars are all passed round the shanks of the needles at substantially the same height below the hooks. This helps to prevent mislapping of'the threads in the hooks of the needles since all the threads will pass into the hooks of the needles at much the same time as the needles move away from the guide eyes. 7 An' example of a machine constructed in accordance with the invention, together "with some, modifications, is illustrated in the accompanying drawings; in which: Figure 1 is a cross-section through a part'of a high speed flat warp knitting machine; a

Figure 2 .shows curves of movement of the knitting elements; Figure 3 is a cross-section through the guides, to a larger scale, showing the component across the row of needles of the movement of the needles relative to the guide eyes; J Figure 4 is a view similar to Figure 3 showing a modified form of guide eyes;

Figure 5 is a similar view to Figure 3 showing a further modified form of guide eyes;

bar 16 which is clamped to a carrier 17 which also extends across the whole width-of the machine and is supported at intervals by arms 18 which are pivoted on vertical pivoted links not shown. The arms 18 are connected at their rear ends by pivots to downwardly extending arms 19 of bell crank levers 20 carried on a shaft 21. Forwardlyv extending arms 22 of the bell crank levers 20 are connected by connecting rods 23 to further eccentrics fixed on the shaft 9.

Two rows of

guide eyes

24 and 25 are carried on

guide bars

26 and 27 respectively,

fI'he guide bars

26 and 27 are carried at intervals along their length by supports 28 i and 29 on which they are arranged to move longtiudinally bell crank lever 33 which 'is'rotatably mounted on a pin 34'. Each bell crank lever-"33 has a second arm 35 con nected by a connecting rod 36 to an eccentric 37 on the driving shaft 9.

= When the main driving shaft 9 is rotated by a driving motor, which is not shown, the eccentrics are rotated so that the needles 1 and the tongues 10 are moved upwards and downwards with a simple harmonic motion and the sinkers 14 and the

guide eyes

24 and 25 are moved to and fro across the row of needles bythe mechanisms by whichthey are respectively connected to the eccentrics on the'shaft 9.

The movement of the needles during each knitting cycle is represented by the curve A in Figure 2 from which it will beseen that the needles are at bottom dead-centre at Figure 6 is a fragmentary perspective view of one of I the rows of guide eyes shown in Figure 3; I Figure 7 is a fragmentary perspective view of the guide eyes shown in Figure 4;

Figure 8 is a fragmentary perspective view of the guide the tongues from the point p to the point q in each knitting eyes shown in Figure 5; and

Figure 9 is a view of the guide eyes as seen in the direction of the arrow IX in Figure 5.

The knitting machine illustrated by way of example in Figure l of the drawings is of the kind which has a row of reciprocating needles arranged side by side in .a

and close the hooks of the needles during different parts of the knitting cycle. Only the bed of the machine is illustrated in Figure 1 of the drawings, together with the knitting elements and their driving mechanisms. The remainder of the machine is quite conventional; that is to say, the bed is supported on a framework which also carries rotatable warp beams from which the warp threads are led over the usual tension bars to the knitting elements, whence the knitted fabric is drawn oil? by draw-ofi rollers and is wound on to a take-up roller in the usual way. I The needles .1 are cast into a bar 2 which is clamped to a carrier 3 which extends. along the whole width of the machine. The carrier 3 is supported at intervals along its length on brackets 4 which are mounted on rods '5. The rods 5 slide upwards and downwards in guides 6 fixed to the bed 7 of the machine. The lower ends of the rods 5 are each connected by a connecting rod 8 to an eccentric .(not shown) which is fixed on adriving shaft 9. Tongues 10 which move within the tubular shanks of the needles 1 are cast into a bar 11 which is clamped'to a carrier 12 which also extends across the Whole width of the machine'and is carried at intervals on brackets '13 which are hidden behind the brackets 4'and are carried on rods similar to the rods 5. The tongues 10 are reciprocated upwards and downwards in the same way as are the needles 1 by further eccentrics fixed ontheshaft 9.

Conventional sinkers 14 having nebs 15 are ca t 1 t 0 degrees in the knitting cycle and are at top dead-centre at 180 degrees. The movement of the tongues is repre sented by curve B. The tongues have a stroke equal to that of the needles, but are at top dead-centre at 260 degrees in the knitting cycle. The hooks are closedby cycle. I The movement of the guide eyes to and fro is represented by curve C in FigureZ, the guide eyes being at the limit of their movement behind the backs of the needle hooks, that is to the left as seen in Figure 1, at 0 degrees and at the limit of their movement to the fronts of the needle hooks, that is to the right as seen in Figure 1, at 180 degrees. The movement of the sinkers is represented by curve D in Figure 2 and the sinkers are moved such that the nebs 15 are in full engagement between the needles at degrees in the knitting cycle and are fully withdrawn to the fronts of the needle books at 290 degrees.

With these movements of the needles and guides, the relative positions of the needles and guides at degrees in the knitting cycle when the needles are in their top dead-centre position is shown in full lines in Figure 3. At 360 degrees in the knitting cycle, the needles have moved down to their bottom dead-centre position and the guides have swung to the backs of the needle hooks so that the relative position of the needles'and guides is as shown in chain dotted lines in Figure 3. The component across the row of needles of the movement of the tops of the needle hooks relative to'the guide eyes is illustrated by the line 38 which therefore has a slope with respect to the plane in which the needles reciprocate which represents the ratiobetween the speed of the guide members and the speed of the needles.

The two rows of guide eyes shown in Figures 1 and 3 of the drawingsare formed from two metal sheets, one edge of each of the sheets being bent round to form

cylindrical tubes

39 and 40 having an internal diameter of /1 inch and each edge is spot welded at intervals to hold it in this position. The edges of the sheets opposite to those which are bent round to form cylindrical tubes are bent round into channel-shaped sections 41 and 42. A series of

slots

43 and 44 are milled in the bottoms of the channels and these slots form the guide eye openings through each pne of which a warp thread 45 passes. The

lengths of the sheets forming the guides are equal to the 'full width of the machine so that one complete row of guide eyes is made in a single piece. The bottoms of the channels 41 and 42 are arranged so that they lie very close to and parallel to the line 38 as the guide eyes move to and fro and the needles move up and down. Both the channels will, therefore, pass at the same distance above the tops of the hooks of the needles and the clearance between the bottoms of the channels and the tops of the hooks of the needles can be made very small.

The last contact of the warp threads 45 with their guide eyes as they pass through the openings will occur with the parts of the guide eyes lying close to the line 38. Therefore, the threads will leave the guide eyes the same distance from the hooks of the needles irrespective of the direction of lay of the threads along the row of needles. It will also be seen from Figure 3 that no part of the guide eyes extends into the path of the warp threads after they have left the openings in the eyes themselves. Thus, any interference between the warp threads 45 passing through the row of guide eyes 24 and the row of guide eyes 25 is prevented and vice versa. Any interference between the threads leaving either the row of guide eyes 24 or the row of guide eyes 25 and adjacent guide eyes in the same row is also prevented.

A modified form of guide eyes which may be used instead of the guide eyes shown in Figures 3 and 6 is shown in Figures 4 and 7. In this modification, each guide eye consists of a tube 46 which is open at its lower end 47 and has a second opening 48 cut by a grinding wheel in its side wall. The machine illustrated in the example is a 28 gauge machine, that is to say it has twentyeight needles to the inch. It must also, therefore, have twenty-eight guide eyes to the inch. Therefore, the tubes 46 are of an inch in outside diameter and are arranged side by side touching each other so that they provide each other with lateral support. The upper end of each tube 49 is swaged and a number of tubes are cast into a metal block 50. A series of metal blocks 50 are arranged side by side and are clamped to the

guide bar

26 or 27. The warp threads 45 pass from the warp beam into the openings 48 and out of the open bottom ends 47 of the tubes and thence to the needles. The bottom ends of the tubes in both the rows of guide eyes attached to the guide bars 26 and 27 lie very close to and in a plane parallel to the line 38 of movement of the needles 1 relative to the guide eyes.

In a further modification shown in Figures 5, 7 and 9*, the guide eyes are formed from loops 51 of circular steel wire .010 inch in diameter. The loops 51 are formed in pairs, each pair being made out of a separate piece of wire. The ends 52 of a number of pieces of wire from which pairs of loops are formed are bent at 45 degrees to the plane of the loops and are cast into a metal block 53. The loops forming the guide eyes are thus held closely side by side as shown most clearly in Figure 9. A number of blocks 53 are fixed to the guide bar 26 to form a complete row of guide eyes.

To form a pair of guide eyes out of a single length of wire, the wire is first bent to form a single loop with its two free ends 52 lying side by side and projecting away from the loop. This single loop is then folded through approximately 180 degrees so that a pair of loops are formed separated by the two ends of the wire, approximately in the shape of a letter B.

In this modification also, the loops 51 are arranged so that they lie close to the line 38 of movement of the tops of the hooks of the needles relative to the guide eyes. The loops lie in a plane parallel to the plane which contains all the lines 38 of movement of the needles in the row.

Only one row of guide eyes is shown in Figure but two or more rows may be provided each with their wire loops lying in the same plane.

Guide eyes made out of circular steel wire in this way have the advantage that the holes have edges of rounded 6 section so that the warp threads passing through them are not damaged and also since they are only supported by the upstanding free ends of the wires, of which the loops are formed, at intervals apart, the visibility of all the eyes in a multi-bar machine is particularly good.

Groups of four loops can be formed out of a single length of wire and to do this, the wire is first bent through degrees in a counter-clockwise direction and back again in a clockwise direction through 360 degrees to form a loop. A second loop is then formed adjacent the first by bending the wire through 360 degrees in a counterclockwise direction, and then a third loop is formed by a third bend through 360 degrees again in a clockwise direction; followed by a final bend through 90 degrees in a counter-clockwise direction so that the two free ends of the wire lie parallel to each other. The first and third loops thus formed lie side-by-side and the second loop lies between the two free ends of the wire in a position ofiset from the first and third loops but mid way between them. The first and third loops are then folded over through degrees towards the two free ends of the wire at right angles to the plane in which the three loops lie.

If groups of four eyes are formed out of a single length of wire in this way, the visibility of all the eyes in a multi-bar machine is still further improved but the support of the eyes is less rigid since there are fewer upstanding ends of wire to fix the loops to the guide bars.

I claim:

1. A high speed fiat warp knitting machine, including a straight row of needles including shanks mounted parallel to each other in a common plane and carrying a hook on the end of each shank, at least two rows of warp thread guide members mounted adjacent said needles for laying warp threads in the books of said needles, each of said members having an eye opening for receiving a thread and a surrounding wall defining the edge of said opening, means for reciprocating said needles in a direction along said shanks with a simple harmonic motion and means for reciprocating said warp thread guide members with a simple harmonic motion in phase with said needles from one side to the other of said common plane and in a plane perpendicular to said common plane, said guide members passing beyond the tops of said needle hooks and reaching the limit of their movement on the open side of the hooks of said needles at the same time as said needles reach the limit of their movement in a direction towards their hooked ends, at least part of each of said surrounding walls having an edge portion adjacent said needles lying in a plane having a slope with respect to the plane of movement of said needles equal to the ratio between the speed of said guide members and the speed of said needles.

2. A knitting machine according to claim 1, in which each guide eye consists of a tube having an opening in one end and a second opening in the side wall, a number of such tubes being fixed side-by-side to a carrier by their ends remote from the open ends.

3. A knitting machine according to claim 2, in which the ends of the tubes which are fixed to the carrier are swaged, the swaged ends being cast or moulded into a block which forms the carrier.

4. A knitting machine according to claim 1, in which the guides comprise a strip which extends along the row of needles, each guide eye consisting of a slot in the strip extending transversely to the row of needles, the slots in the strip being formed side-by-side and parallel to each other.

5. A knitting machine according to claim 4, in which one longitudinal edge of the strip is bent to form a tube and the other longitudinal edge is bent into a channelshaped section, the slots being formed in the bottom of the channel.

6. A knitting machine according to claim 1, in which each guide eye consists of a loop of wire.

, '7 7 j :7. A knitting machine acepfding to claim 6, in which tw o or mqre adjacent guide eyes are formed from a single piege 'of wire, the ends of which are cast or moulded into a block which forms 'a carrier.

References Cited in the file of this patent UNITED STATES PATENTS Roberts Dec. 15, 1891 Paget Apr. 1, 1930 8 Agulnek Oct; 10, 1939 Peel et a1 Aug. 4, 1942 Young Oct. 7, 1947 Eshleman Aug. 30, 1949 Wilson Sept. 26, 1950 Walford June 15, 1954 Peters Jan. 18, 1955 Feustel et a1. Oct. 11, 1955 Schoeuster Feb. 11, 1958